Book of Abstract Book Of Abstracts FLUORINE FRONTIERS: A Symposium Honoring the Legacy of Boris Žemva September 9-11, 2024 Jožef Stefan Institute, Ljubljana, Slovenia Book of Abstracts FLUORINE FRONTIERS: A Symposium Honoring the Legacy of Boris Žemva Publisher: Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia Organizer: Jožef Stefan Institute, Department of Inorganic Chemistry and Technology, Jamova cesta 39, Ljubljana, Slovenia Editor: Evelin Gruden Editorial board: Gašper Tavčar, Melita Tramšek, Evelin Gruden Graphic designer: Lenka Trdina Online edition Ljubljana, September, 2024 CIP Kataložni zapis o publikaciji (CIP) pripravili v Narodni in univerzitetni knjižnici v Ljubljani COBISS.SI-ID 206738179 ISBN 978-961-264-294-5 (PDF) CONTENTS Introduction .................................................................................................................................5 Timetable ....................................................................................................................................7 Program .......................................................................................................................................8 Abstracts - Lecture sessions ......................................................................................................15 Abstracts - Student session .......................................................................................................43 INTRODUCTION Fluorine Frontiers: A Symposium Honoring the Legacy of Boris Žemva Welcome to “Fluorine Frontiers: A Symposium Honoring the Legacy of Boris Žemva”. We are delighted that you are able to join us to celebrate Boris Žemva’s life and to explore his pioneering contributions to the field of fluorine chemistry. To begin, we would like to give you a brief overview of his life and achievements. Prof. Dr. Boris Žemva’s remarkable scientific journey began at the University of Ljubljana, where he pursued his passion for chemistry and earned his Ph.D. in 1971. His academic pursuits led him to the Jožef Stefan Institute, where he delved into the intriguing world of noble-gas chemistry and focussed on the reactions between xenon and fluorine. This research laid the foundation for his distinguished career as a prominent figure in the field. Throughout his tenure from 1983 to 2006 as the head of the Department of Inorganic Chemistry and Technology at the Jožef Stefan Institute, Prof. Žemva’s leadership and vision extended far beyond the confines of fluorine chemistry. Under his guidance, the department addressed a multitude of scientific challenges, ranging from basic research in fluorine chemistry to tech-nological advancements. His commitment to education in chemistry further demonstrated his passion for cultivating knowledge and innovation in future generations of scientists. It is note-worthy that his involvement in this sphere is exemplified by his continued participation in the International Postgraduate School at the Jožef Stefan Institute, which served to emphasize his dedication to nurturing scientific excellence. The collaborative efforts between research groups in Ljubljana and Berkeley paved the way for ground-breaking research that led to the syntheses of thermodynamically unstable high-oxidation-state fluorides. Prof. Žemva’s impactful contributions in this area, alongside his colleague Prof. Neil Bartlett, were recognized by Nobel Laureate in Chemistry, Prof. Roald Hoffmann, who underscored their pioneering work on high-energy oxidants. Prof. Žemva’s influence extended globally, with over 150 published articles, numerous invited lectures, and pivotal editorial roles in esteemed scientific journals. His research results significantly contributed to our understanding of chemistry and are often described and cited in contemporary inorganic chemistry textbooks. His involvement in organizing international sym-posiums and conferences further solidified his role in the international fluorine chemistry community. He collaborated closely with numerous scientists and research groups from around the world, including Japan, Germany, France, Poland, the USA, and Canada. He often mentioned that close collaboration with people worldwide is invaluable and should be nurtured. He greatly enjoyed the company of his international friends and colleagues. Notable accolades such as the Boris Kidrič Award, Alexander von Humboldt Research Award, American Chemical Society (ACS) Award, and the prestigious Zois Award exemplified the recognition of his outstanding contributions to the field of fluorine chemistry. Beyond his scientific endeavours, Prof. Žemva found joy in diverse interests, including outdoor pursuits like hiking and skiing, appreciation of music, and savouring good food and wine. 5 A gathering at the Jožef Stefan Institute in Ljubljana is being organized to celebrate Prof. Žem-va’s illustrious career and scientific achievements in the field of fluorine chemistry. This event will serve as a tribute to his legacy, emphasizing the importance of his research and the impact he had on the scientific community. Your presence in Slovenia at this gathering of friends and colleagues is warmly anticipated, and promises to be a memorable and scientifically enriching experience that will provide opportunities for collaborations and reflection on the enduring legacy of Prof. Dr. Boris Žemva. Sincerely yours, The Symposium Organizing Committee: Assoc. Prof. Gašper Tavčar Dr. Evelin Gruden Dr. Hélène P. A. Mercier Prof. Gary J. Schrobilgen Dr. Melita Tramšek 6 TIMETABLE Sunday September 8 18:00–21:00 Welcome Reception & Registration Monday Tuesday Wednesday September 9 September 10 September 11 8:00–9:00 Registration Registration Registration 9:00–9:30 Welcome Address & 9:30–10:00 Opening Session Lecture Session 4 Lecture Session 8 10:00–10:30 10:30–11:00 Coffee Break Coffee Break 11:00–11:30 Coffee Break 11:30–12:00 Lecture Session 1 Lecture Session 5 Student Session 12:00–12:30 12:30–13:00 Lunch Break Lunch Break & Group Photo Closing Remarks 13:00–13:30 & Lunch 13:30–14:00 14:00–14:30 Lecture Session 2 Lecture Session 6 14:30–15:00 15:00–15:30 Coffee Break Coffee Break 15:30–16:00 16:00–16:30 Lecture Session 3 Lecture Session 7 16:30–17:00 Tour of Ljubljana 17:00–17:30 17:30–18:00 19:00–22:00 Symposium Dinner 7 PROGRAM Sunday, September 8, 2024 18:00–21:00 Welcome Reception & Registration Gallery Monday, September 9, 2024 8:00–9:00 Registration Gallery 9:00–9:30 Welcome Address Main Lecture Hall OPENING SESSION Main Lecture Hall 9:30–10:00 Melita Tramšek & Gašper Tavčar 10:00–10:30 Hélène P. A. Mercier & Gary J. Schrobilgen 10:30–11:00 Coffee Break Gallery LECTURE SESSION 1 Main Lecture Hall The Intermediates of the Schmidt Reaction and a 11:00–11:30 L1 Pictorial of Boris Karl O. Christe, Thomas Saal, Antonina Nazarova, p. 17 Ralf Haiges, David Dixon A Personal Journey into Applications of XeF2 in Synthetic 11:30–12:00 L2 Organic Chemistry and the Quest for the Xe-C Bond p. 18 Yurii L. Yagupolskii 12:00–12:30 L3 Fluoride ion and Alcohols: Good friends? Kazuhiko Matsumoto, Nozomi Yoneda, Kohei Tada p. 19 12:30–13:30 Lunch Break Gallery 8 LECTURE SESSION 2 Main Lecture Hall 13:30–14:00 L4 My Fluorine Chemistry and Ljubljana Konrad Seppelt p. 20 14:00–14:30 L5 Fluorine-Forged Friendship Olga Boltalina, Sebastian Balser, Steven H. Strauss p. 21 Nucleophilic Fluorination Reagents Based on 14:30–15:00 L6 Difluorosilicates and Difluoroimidazoles Jaroslav Kvíčala, Markéta Rybáčková, Šárka Bouzková, p. 22 Adam Hroch, Michal Trojan, G. Tavčar 15:00–15:30 Coffee Break Gallery LECTURE SESSION 3 Main Lecture Hall Chemical In-Depth Analysis of (Ca/Sr)F2 Core-Shell Like 15:30–16:00 L7 Nanoparticles by X Ray Photoelectron Spectroscopy with Tunable Excitation Energy p. 23 E. Kemnitz, A. Müller, Th. Krahl, B. Ritter, W. E. S. Unger 16:00–16:30 L8 Simplifying Fluoroalkylation Reactions with Nickel David A. Vičič, Cherry Mae Ravidas, Scott T. Shreiber p. 24 RuF6, a stronger Oxidizing Agent than PtF6: Oxidation of 16:30–17:00 L9 Halogen Pentafluorides with RuF6 p. 25 Florian Kraus, Björn N. Koch 9 Tuesday, September 10, 2024 8:00–9:00 Registration Gallery LECTURE SESSION 4 Main Lecture Hall Structural Peculiarities of some d-Transition Compounds 9:00–9:30 L10 in Fluorinated Environments p. 26 Alain Tressaud 9:30–10:00 L11 α-Silyl Carbanions Stabilized by Pentafluoroethyl Groups Berthold Hoge, Julia Landwehrmann p. 27 Fluorochemicals with Uniquely Important Applications in 10:00–10:30 L12 Electronics p. 28 Robert (Bob) G. Syvret 10:30–11:00 Coffee Break Gallery LECTURE SESSION 5 Main Lecture Hall Adventures in Xenon- and Mercury-Chemistry with 11:00–11:30 L13 Weakly Coordinating Perfluoroalkoxyaluminate Anions p. 29 Ingo Krossing, Konstantin Kloiber Novel two-dimensional quantum magnets based on Ag(II) 11:30–12:00 L14 Wojciech Grochala, Mateusz Domanski, Daniel Jezierski, p. 30 Zoran Mazej Tris(pentafluoroethyl)difluorophosphorane: 12:00–12:30 L15 A Versatile Fluoride Acceptor for Transition Metal Chemistry p. 31 Udo Radius 12:30–13:20 Lunch Break Gallery 13:20–13:30 Group Photo Stairs in front of IJS main building 10 LECTURE SESSION 6 Main Lecture Hall Unusual Fluorine Containing Compounds: 13:30–14:00 L16 from Oxyfluorides and High Potential Oxidizers p. 32 Sebastian Riedel Fluorinated aminophospohonates and amino acids with 14:00–14:30 L17 olefinic motif – versatile peptidomimetics Henryk Koroniak, Marcin Kaźmierczak, p. 33 Katarzyna Koroniak-Szejn, Karolina Paszek One Of The Smallest Elements Of The Periodic Table, But 14:30–15:00 L18 The Diamond Of Our Life, Element F2 Dayal T. Meshri, Sanjay D. Meshri, Elena Shembel, p. 34 Ritesh Jain, Prakash Iyer 15:00–15:30 Coffee Break Gallery LECTURE SESSION 7 Main Lecture Hall Rhodium-Mediated C-H and C-F Bond Activation to 15:30–16:00 L19 Access Fluorinated Alkene Derivatives Thomas Braun, Cortney von Hahmann, Maria Talavera, p. 35 Soodeh Mollasalehi Unusual Reactivity Triggered By Fluorine – From Exotic Complexes To Novel Reaction Mechanisms 16:00–16:30 L20 Przemysław J. Malinowski, p. 36 Magdalena Grochowska-Tatarczak, Michał Jadwiszczak, Kacper Koteras, Piotr J. Leszczyński 16:30–17:00 L21 Theranostic Applications of Fluorinated Dendrimers Pierangelo Metrangolo p. 37 19:00–22:00 Symposium Dinner Ljubljana Castle 11 Wednesday, September 11, 2024 8:00–9:00 Registration Gallery LECTURE SESSION 8 Main Lecture Hall Electrochemical Fluorination: 9:00–9:30 L22 Synthesis of Fluorine-Containing Building Blocks Maik Finze, Nikolai V. Ignat’ev, Leon N. Schneider, p. 38 Tanja Knuplez, Younes K. J. Bejaoui, Roland Graf 9:30–10:00 L23 High-pressure chemistry and physics of fluorides Dominik Kurzydłowski p. 39 Chloroimidazolium Deoxyfluorination Reagent with H2F3-10:00–10:30 L24 Anion as a Sole Fluoride Source p. 40 Gašper Tavčar, Jernej Iskra Do We Still Need To Determine Crystal Structures 10:30–11:00 L25 Experimentally? p. 41 Horst Borrmann 11:00–11.30 Coffee Break Gallery 12 STUDENT SESSION Main Lecture Hall Phase Transitions in Compressed Palladium Trifluoride 11:30–11:37 S1 Sylwia Olszewska, Deepak Upadhyay, Sharad Babu Pillai, Kinga Zdun, Jakub Drapała, Klemen Motaln, Matic Lozinšek, p. 45 Dominik Kurzydłowski Preparation and Structural Characterisation of Salts 11:37–11:44 S2 Containing the Unique [ MF3(XeF2)3]+ ( M = Pd, Pt) Adduct Cations p. 46 Klemen Motaln, Matic Lozinšek Pyridine and pentafluoropyridine as ligands in transition 11:44–11:51 S3 metal complexes p. 47 Michał J. Jadwiszczak, Przemysław J. Malinowski Protective Role of Aluminium Against Fluoride Toxicity in 11:51–11:58 S4 THP-1 Monocytes Anja Pavlovič, Larisa Janžič, Lucija Sršen, p. 48 Andreja Nataša Kopitar, Maja Ponikvar-Svet Hydrosilylation of olefins on highly reactive calcium cation 11:58–12:05 S5 Magdalena Grochowska-Tatarczak, Kacper Koteras, p. 49 Krzysztof Kazimierczuk, Przemysław J. Malinowski Novel XeII−N-bonded compounds derived from cyanogen 12:05–12:12 S6 Erik Uran, Kristian Radan, Miha Virant, Mirela Dragomir, p. 50 Matic Lozinšek Trifluoromethylthiolation: A Strategy for Hydrophobic 12:12–12:19 S7 Peptide Development Jure Gregorc, Nathalie Lensen, Gregory Chaume, p. 51 Thierry Brigaud, Jernej Iskra Carboxylic Acids to Acyl Fluorides: An Easy Access for 12:19–12:26 S8 Amides and Esters Jan Jelen, Griša Prinčič, Nina Cankar, Jernej Iskra, p. 52 Gašper Tavčar 12:30–14:00 Closing remarks & Lunch Gallery 16:00–18:00 Tour of Ljubljana Ljubljana city center 13 ABSTRACTS Lecture sessions L1 FLUORINE FRONTIERS 2024 The Intermediates of the Schmidt Reaction and a Pictorial of Boris Karl O. Christe,1* Thomas Saal,1 Antonina Nazarova,1 Ralf Haiges,1 David Dixon2 1 Loker Research Institute and Department of Chemistry, University of Southern California, Los Angeles, CA 90089-1661,USA, 2 Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, AL 35487-0336, USA *e-mail: kchriste@usc.edu Abstract Boris was not only a brilliant scientist but also enjoyed life to the fullest. A series of pictures will be presented, demonstrating his joie de vivre. A summary will be given about the isolation and characterization of the intermediates of the Schmidt reaction. Acyl azides, RCON3, are the starting materials for both the Schmidt reaction and the Curtius rearrangement. However, these two reactions are very different. The Curtius rearrangement, the conversion of an acyl azide to an acyl isocyanate, RCON3 → RNCO + N2 (1) is a simple one-step, intramolecular, thermal rearrangement with N2 elimination. In contrast, the Schmidt reaction, the conversion of an acyl azide to an alkyl amine involving N2 and CO2 eliminations, RCON3 + H2O → RNH2 + N2 + CO2 (2) is a low-temperature, acid catalyzed, multi-step reaction whose complex mechanism had not been established before. 17 Abstracts L2 A Personal Journey into Applications of XeF2 in Synthetic Organic Chemistry and the Quest for the Xe-C Bond Prof. Dr. Yurii L. Yagupolskii * Institute of Organic Chemistry National Academy of Sciences Of Ukraine, 5 Academic Valery Kukhar str, Kyiv 02098, Ukraine *e-mail: yurii.yagupolskii@gmail.com Among the pages of my research career that have been of most importance to me are those that chronicle the time I spent exploring the reactivity of XeF2: Perfluoroalkyl sulfur and selenium difluoride substituent ArS(orSe)F2CF3 construction [1]: ArS(Se)CF3 + XeF2 → Ar SF2(SeF2)CF3 The syntheses of N-F compounds (RfCO2)2NF [2]: (RfCO)2NH + XeF2 → (RfCO)2NF Long term search for Xe-N and Xe-C containing stable molecules [3]: These were great and unforgettable times [4], which carry with them great memories of cooperations, meetings and friends in the fluorine community. Among them, it was the wise and friendly smile of Professor Boris Zemva. References [1] Yu.L.Yagupol’skii, T.I. Savina, Reaction of aryl trifluoromethyl sulfides and selenides with xenon difluoride // Zh. Org. Khim.- 1979.- Vol. 15(2).- P. 438-439 (Russ). (CA – Vol. 90 – 203618p). [2] Yu. L.Yagupol'skii, T. I. Savina, Reaction of imides of perfluorodicarboxylic acids with xenon difluoride // J. Org. Chem. USSR (English Translation).- 1981.- Vol. 17(6).- P. 1180 – 1181. (Zh. Organ. Khim.- 1981.- Vol. 17(6).- P. 1330 – 1331). [3] Yu.L.Yagupolskii, W.Tyrra, R.Gnann, N.Maggiarosa, Naumann D. 2,6-Difluorphenylxenon(II) bis(fluorsulfonyl)amid, -bis(trifluormethylsulfonyl)amid, tris(fluorsulfonyl)methanid und - bis(trifluormethylsulfonyl)methanid - neue C-Xe-N- und C-Xe-C-Verbindungen? // J. Fluorine Chem.- 2002.- Vol. 113, № 2.- P. 143-146. [4] Yu.L. Yagupolskii, Introduction of Fluorine with Noble Gas Fluorides / Organo-Fluorine Compounds (Houben-Weyl). / Eds. B.Baasner, H.Hagemann, J.C.Tatlow.- Stuttgart, New York: Theme, 2000.- Vol. E 10a.- P. 219-233. 18 L3 FLUORINE FRONTIERS 2024 A Personal Journey into Applications of XeF2 in Synthetic Organic Fluoride ion and Alcohols: Good friends? Chemistry and the Quest for the Xe-C Bond Kazuhiko Matsumoto,1* Nozomi Yoneda,1 Kohei Tada2 Prof. Dr. Yurii L. Yagupolskii * 1 Graduate School of Energy Science, Kyoto University, Yoshida, Sakyo-ku, Kyoto, JAPAN 2 Institute of Organic Chemistry National Academy of Sciences Of Ukraine, 5 Academic Valery Kukhar str, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, JAPAN Kyiv 02098, Ukraine *e-mail: matsumoto.kazuhiko.4c@kyoto-u.ac.jp *e-mail: yurii.yagupolskii@gmail.com Interactions of alcohols and fluoride are of interest for researchers in view of its importance in Among the pages of my research career that have been of most importance to me are those that the design of chemical[1,2] and electrochemical[3,4] reactions. In such systems, the interaction chronicle the time I spent exploring the reactivity of XeF2: between fluoride ion and hydroxy group is a key factor to determine the activity of fluoride ion, and thus the structural insights on it attracts significant attentions. This study discusses the Perfluoroalkyl sulfur and selenium difluoride substituent ArS(orSe)F2CF3 construction [1]: impact of fluorination of alcohols on their interaction with fluoride ion through experimental and theoretical data. The CsF-hexafluoroisopropanol (HFIP) system exhibits a significantly ArS(Se)CF3 + XeF2 → Ar SF2(SeF2)CF3 larger interaction energy than that of the CsF-isopropanol (IP) system (Figure 1) as indicated by the activity coefficient measurements.[5] The syntheses of N-F compounds (RfCO2)2NF [2]: (RfCO)2NH + XeF2 → (RfCO)2NF Long term search for Xe-N and Xe-C containing stable molecules [3]: Figure 1. Comparison between interaction energies Figure 2. Activity coefficients of These were great and unforgettable times [4], which carry with them great memories of of HFIP---F− and IP---F−.[5] alcohols for the CsF−IP and cooperations, meetings and friends in the fluorine community. Among them, it was the wise CsF−HFIP systems at 25 °C[5] and friendly smile of Professor Boris Zemva. References References [1] J. W. Lee, M. T. Oliveira, H. B. Jang, S. Lee, D. Y. Chi, D. W. Kim, C. E. Song, Chem. Soc. Rev. 45, 4638- [1] Yu.L.Yagupol’skii, T.I. Savina, Reaction of aryl trifluoromethyl sulfides and selenides with xenon difluoride 4650, 2016. // Zh. Org. Khim.- 1979.- Vol. 15(2).- P. 438-439 (Russ). (CA – Vol. 90 – 203618p). [2] K. M. Engle, L. Pfeifer, G. W. Pidgeon, G. T. Giuffredi, A. L. Thompson, R. S. Paton, J. M. Brown, V. [2] Yu. L.Yagupol'skii, T. I. Savina, Reaction of imides of perfluorodicarboxylic acids with xenon difluoride // J. Gouverneur, Chem. Sci. 6, 5293-5302, 2015. Org. Chem. USSR (English Translation).- 1981.- Vol. 17(6).- P. 1180 – 1181. (Zh. Organ. Khim.- 1981.- Vol. [3] R. Francke, D. Cericola, R. Kötz, D. Weingarth, S. R. Waldvogel, Electrochim. Acta 62, 372-380, 2012. 17(6).- P. 1330 – 1331). [4] N. Shida, H. Takenaka, A. Gotou, T. Isogai, A. Yamauchi, Y. Kishikawa, Y. Nagata, I. Tomita, T. Fuchigami, [3] Yu.L.Yagupolskii, W.Tyrra, R.Gnann, N.Maggiarosa, Naumann D. 2,6-Difluorphenylxenon(II) S. Inagi, J. Org. Chem. 86, 16128-16133, 2021. bis(fluorsulfonyl)amid, -bis(trifluormethylsulfonyl)amid, tris(fluorsulfonyl)methanid und - [5] N. Yoneda, H. Iyama, T. Nagata, M. Katahira, Y. Ishii, K. Tada, K. Matsumoto, R. Hagiwara J. Phys. Chem. bis(trifluormethylsulfonyl)methanid - neue C-Xe-N- und C-Xe-C-Verbindungen? // J. Fluorine Chem.- 2002.- Vol. Lett. 15 , 1677-1685, 2024. 113, № 2.- P. 143-146. [4] Yu.L. Yagupolskii, Introduction of Fluorine with Noble Gas Fluorides / Organo-Fluorine Compounds (Houben-Weyl). / Eds. B.Baasner, H.Hagemann, J.C.Tatlow.- Stuttgart, New York: Theme, 2000.- Vol. E 10a.- P. 219-233. 19 Abstracts L4 My Fluorine Chemistry and Ljubljana Konrad Seppelt Institut für Chemie und Biochemie, Freie Universität Berlin, Germany Fabeckstrasse 34 - 36, 14195 Berlin, Germany *e-mail: seppelt@chemie.fu-berlin.de The accidental isolation of the pentafluoro-selenic acid HOSeF5 in 1972 has been our starting point of more than 50 years of our fluorine chemistry [1]. I had the honor to present my work at the first European Symposium on Fluorine chemistry in Ljubljana the same year. I also participated in the Symposia on Fluorine chemistry in Bled and again Ljubljana, which had been organized by Boris Zemva. Our work advanced with the worldwide advance in fluorine chemistry. We have tried to focus as much as possible on fundamental problems in the field. The experimental work ended 50 years later with investigations on BrO2F [2]. References [1] K. Seppelt, Angew. Chem. Int. Ed. 11, 630, 1972 [2] K. Seppelt, Angew. Chem. Int. Ed. 58, 189286, 2019 20 L5 FLUORINE FRONTIERS 2024 Fluorine-Forged Friendship Olga Boltalina, Sebastian Balser, Steven H. Strauss Department of Chemistry, Colorado State University, Fort Collins, USA *e-mail: ovbolt@colostate.edu The author’s collaboration with Boris Zemva has started at the pivotal period of her research of the new class of fluorinated carbon compounds – fluorofullerenes, following her serendipitous discovery of the selective fullerene fluorination with transition metal fluorides as mild fluorinating reagents. At that time, all the local resources of fluorinating reagents that the author’s team could make or receive from collaborators in Russian institutions have been exhausted, while many unanswered fundamental questions regarding the reactivity of fullerenes and the mechanisms of their fluorination remained. As often happens in the fluorine community, it was at the 11th ESFC in Slovenia that Boris and I met and I asked him if he would be interested in collaborating. His answer was swift and positive and in no time we started receiving unique samples of various metal fluorides that we used in our lab to continue the quest for the best fluorinating agents for the fluorination of C60. This collaboration yielded several publications, conference presentations and lab visits.[1-4] The highlights of this research will be presented in this lecture. In the second part of the lecture, the current results of our synthetic efforts towards fluorinated carbon-rich materials for organic optoelectronics will be presented. Recently, a drastic turn from gas/solid, solvent-free, high-temperature, and hence - thermodynamically controlled fluorinations and perfluoroalkylations, that we were mastering in our labs for years, has been made. This new direction involves light-induced room-temperature perfluoroalkylations of polycyclic (hetero)- aromatic substrates in organic solvents. In the past few years, photochemical perfluoroalkylations have become one of the most intensely studied reactions among synthetic fluoroorganic chemists.[5,6] Initial results involving an array of PAH substrates, perfluoroalkylating reagents and photocatalysts under varying experimental conditions will be discussed, with the focus on intramolecular fluorocyclizations. References [1] N. I. Denisenko, S. I. Troyanov, A. A. Popov, I. V. Kuvychko, B. Zemva, E. Kemnitz, S. H. Strauss, O. V. Boltalina, J. Am. Chem. Soc. 126, 1618-1619, 2004. [2] A. A. Goryunkov, I. E. Kareev, I. N. Ioffe, A. A. Popov, I. V. Kuvychko, V. Y. Markov, I. V. Goldt, A. S. Pimenova, M. G. Serov, S. M. Avdoshenko, P. A. Khavrel, L. N. Sidorov, S. F. Lebedkin, Z. Mazej, B. Zemva, S. H. Strauss, O. V. Boltalina, J. Fluorine Chem. 127, 1423-1435, 2006. [3] A. A. Goryunkov, V. Y. Markov, O. V. Boltalina, B. Zemva, A. K. Abdul-Sada, R. Taylor, J. Fluorine Chem. 112, 191-196, 2001. [4] A. A. Goryunkov, Z. Mazej, B. Zemva, S. H. Strauss, O. V. Boltalina, Mendeleev Commun. 16, 159-161, 2006. [5] N. J. Straathof, D. J. van Osch, A. Schouten, X. Wang, J. C. Schouten, V. Hessel, T. Noël, J. Flow Chem. 4, 12-17, 2014. [6] T. Liu, J. Liu, J. He, Y. Hong, H. Zhou, Y.-L. Liu, S. Tang, Synthesis 54, 1919-1938, 2022. 21 Abstracts L6 Nucleophilic Fluorination Reagents Based on Difluorosilicates and Chemical In-Depth Analysis of (Ca/Sr)F2 Core-Shell Like Nanoparticles Difluoroimidazoles by X-Ray Photoelectron Spectroscopy with Tunable Excitation Energy Jaroslav Kvíčala,1* Markéta Rybáčková,1 Šárka Bouzková,1 Adam Hroch,1 Michal Trojan,1 G. E. Kemnitz1), A. Müller2), Th. Krahl1), B. Ritter1), W. E. S. Unger2), Tavčar2 1) Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin 1 2) Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203, Berlin Prague 6, Czech Republic 2 Department of Inorganic Chemistry and Technology, ”Jožef Stefan” Institute, Jamova cesta 39, Ljubljana, *e-mail erhard.kemnitz@chemie.hu-berlin.de Slovenia The fluorolytic sol-gel synthesis [1] is applied with the intention to obtain two different types *e-mail: kvicalaj@vscht.cz of core-shell nanoparticles, namely SrF2-CaF2 and CaF2-SrF2. In two separate fluorination steps for core and shell formation, the corresponding metal lactates are reacted with anhydrous HF Fluorination of secondary and phenolic substrates belongs to the most tedious processes of in ethylene glycol [2]. Scanning transmission electron microscopy (STEM) and dynamic light organofluorine chemistry. We studied fluorination of secondary substrates, especialy bromides and mesylates, with modified difluorosilicates, and fluorination of activated phenols with scattering (DLS) confirm the formation of particles with mean dimensions between 6.4 and difluorobenzimidazole, modified with 4-tolyl groups. 11.5 nm. The overall chemical composition of the particles during the different reaction steps is monitored by quantitative Al Kα excitation X-ray photoelectron spectroscopy (XPS). Here, the formation of stoichiometric metal fluorides (MF2) is confirmed, both for the core and the final core-shell particles[3]. Furthermore, an in-depth analysis by synchrotron radiation XPS (SR-XPS) with tunable excitation energy is performed to confirm the core-shell character of the nanoparticles. In principle, core-shell like structures are formed, but without a sharp interface between calcium Figure 1: Fluorination of secondary substrates with modified difluorosilicates and of activated phenols with modified difluorobenzimidazole and strontium containing phases. Surprisingly, the in-depth chemical distribution of the two types of nanoparticles is equal within the error of the experiment. Both comprise a SrF2-rich First part dealt with modifications of the TBAT reagent, developed by Pilcher at al. [1]. We core domain and CaF2-rich shell domain with an intermixing zone between them. Consequently, found that substitution of the tetrabutylammonium cation, prone to elimination, for other more the internal structure of the final nanoparticles seems to be independent from the synthesis stable quaternary ammonium cations did not improve fluorination yields [2]. On other hand, chronology. modification of the phenyl ring by electron donating methoxy group(s) improved the fluorination selectivity, while electron accepting trifluoromethyl group had adverse effect [3]. In the second part, we studied new difluoroimidazole compound, an analogue of successful Ritter’s PhenoFluorTM reagent [4], the synthesis of which does not require intermediary NHC species. The reagent gave moderate yields of fluorobenzenes with activated phenols, while large amounts of the corresponding diphenyl ethers were formed as side products [5]. Experimental results were accompanied by DFT calculations attempting to explain the differences in reactivity compared to the commercial reagents. References [1] A.S. Pilcher, H.L. Ammon, P. DeShong, J. Am. Chem. Soc. , 117, 5166-5167, 1995. References (Bold, 11pt, Align Left) [2] M. Trojan, K. Kučnirová, Š. Bouzková, J. Cvačka, J. Čejka, G. Tavčar, M. Rybáčková, J. Kvíčala, Org. & [1] E. Kemnitz; U. Groß; S. Rüdiger; C. S. Shekar, Angew. Chem. 115, 4383, 2003; Angew. Chem. Int. Ed. 42, Biomol. Chem. , 22, 1047-1056, 2024. 4251, 2003. [3] M. Trojan, A. Hroch, E. Gruden, J. Cvačka, J. Čejka, G. Tavčar, M. Rybáčková, J. Kvíčala, RSC Adv. , 14, [2] S. Rüdiger; E. Kemnitz, Dalton Trans. 1117, 2008,. 22326-22334, 2024. [3] B. Ritter; T. Krahl; K. Rurack; E. Kemnitz, J. Mater. Chem. C, 2, 8607, 2014. [4] P. Tang, W. Wang, T. Ritter, J. Am. Chem. Soc. , 133, 11482-11484, 2011. [5] Š. Bouzková, J. Cvačka, J. Čejka, G. Tavčar, J. Kvíčala, M. Rybáčková, manuscript in preparation. 22 L7 FLUORINE FRONTIERS 2024 Chemical In-Depth Analysis of (Ca/Sr)F2 Core-Shell Like Nanoparticles by X-Ray Photoelectron Spectroscopy with Tunable Excitation Energy E. Kemnitz1), A. Müller2), Th. Krahl1), B. Ritter1), W. E. S. Unger2), 1) Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin 2) Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203, Berlin *e-mail erhard.kemnitz@chemie.hu-berlin.de The fluorolytic sol-gel synthesis [1] is applied with the intention to obtain two different types of core-shell nanoparticles, namely SrF2-CaF2 and CaF2-SrF2. In two separate fluorination steps for core and shell formation, the corresponding metal lactates are reacted with anhydrous HF in ethylene glycol [2]. Scanning transmission electron microscopy (STEM) and dynamic light scattering (DLS) confirm the formation of particles with mean dimensions between 6.4 and 11.5 nm. The overall chemical composition of the particles during the different reaction steps is monitored by quantitative Al Kα excitation X-ray photoelectron spectroscopy (XPS). Here, the formation of stoichiometric metal fluorides (MF2) is confirmed, both for the core and the final core-shell particles[3]. Furthermore, an in-depth analysis by synchrotron radiation XPS (SR-XPS) with tunable excitation energy is performed to confirm the core-shell character of the nanoparticles. In principle, core-shell like structures are formed, but without a sharp interface between calcium and strontium containing phases. Surprisingly, the in-depth chemical distribution of the two types of nanoparticles is equal within the error of the experiment. Both comprise a SrF2-rich core domain and CaF2-rich shell domain with an intermixing zone between them. Consequently, the internal structure of the final nanoparticles seems to be independent from the synthesis chronology. References (Bold, 11pt, Align Left) [1] E. Kemnitz; U. Groß; S. Rüdiger; C. S. Shekar, Angew. Chem. 115, 4383, 2003; Angew. Chem. Int. Ed. 42, 4251, 2003. [2] S. Rüdiger; E. Kemnitz, Dalton Trans. 1117, 2008,. [3] B. Ritter; T. Krahl; K. Rurack; E. Kemnitz, J. Mater. Chem. C, 2, 8607, 2014. 23 Abstracts L8 Simplifying Fluoroalkylation Reactions with Nickel David A. Vičič,* Cherry Mae Ravidas, Scott T. Shreiber Lehigh University, Bethlehem, PA USA *e-mail: vicic@lehigh.edu Simple nickel salts have been prepared that either bear only fluoroalkyl ligands or fluoroalkyl ligands with solvent a co-ligands.[1-3] These complexes were characterized by a variety of analytical techniques in order to provide insights into their electronic structures and reactivities. Trifluoromethyl and perfluoroethyl derivatives were prepared in order to compare and contrast their reactivities and fundamental properties. Reactivities that will be discussed include catalytic C-H perfluoroalkylations of electron rich arenes, stereoselective perfluoroalkylation of natural products, and stubborn reductive eliminations involving the perfluoroalkyl groups. Figure 1: Trifluoromethyl and perfluoroethyl nickel complexes bearing simple supporting co-ligands. References [1] S. T. Shreiber and D. A. Vicic Angew. Chem. Int. Ed. 2021, 60, 18162-18167 . [2] S. T. Shreiber and D. A. Vicic Tetrahedron Lett. 2022, 97, 153795 . [3] C. M. Ravidas and D. A. Vicic, Organometallics 2024, 43, 706-712. 24 L9 FLUORINE FRONTIERS 2024 RuF6, a stronger Oxidizing Agent than PtF6: Oxidation of Halogen Pentafluorides with RuF6 Florian Kraus,1* Björn N. Koch1 1Fachbereich Chemie, Philipps-Universität Marburg, Germany *e-mail: F.kraus@uni-marburg.de Platinum hexafluoride is known for its enormous oxidizing power. It gained its popularity mainly due to its ability to oxidize Xe, forming the first noble gas compound “XePtF6”.[1] It was only a few years later that the actual composition of the reaction products could be determined, which was a mixture of [XeF][PtF6] and [XeF][Pt2F11].[2] In addition to Xe, PtF6 is also able to oxidize various other compounds whose oxidation seemed impossible at the time. For example, NF3 or ClF5 can be oxidized to the coordinatively saturated cations [NF4]+ or [ClF6]+.[3,4] However, the formation of [BrF6]+ by the reaction of BrF5 and PtF6 is not possible. To oxidize BrF5, even stronger oxidizing agents such as [KrF]+ or [NiF3]+ generated in situ are required.[5] Our work shows that RuF6 is able to oxidize all known halogen pentafluorides X F5 ( X = Cl, Br, I) at room temperature to the respective [ X F6]+ salts, according to equation (1). X F5 + 2 RuF6 [ X F6][Ru2F11] (1) The compounds obtained were characterized using various methods, e.g. Raman spectroscopy and single-crystal X-ray structure analysis. References (Bold, 11pt, Align Left) [1] N. Bartlett, Proc. Chem. Soc. 1962, 218–218. [2] L. Graham, O. Graudejus, N. K. Jha, N. Bartlet , Coord. Chem. Rev. 2000, 197, 321–334. [3] K. O. Christe, W. W. Wilson, E. C. Curtis, Inorg. Chem. 1983, 22, 3056–3060. [4] F. Q. Roberto, Inorg. Nucl. Chem. Lett. 1972, 8, 737–740. [5] T. Schroer, K. O. Christe, Inorg. Chem. 2001, 40, 2415–2419. 25 Abstracts L10 Structural Peculiarities of some d-Transition Compounds in Fluorinated Environments Alain Tressaud,1 1 ICMCB-CNRS, University Bordeaux, France & EurASc, Brussels, Belgium *e-mail: atressaud@gmail.com This work focuses on two singular examples: i) the room-temperature structure of Pd(II) compounds synthesized in aHF, and ii) one of the very rare Jahn-Teller Cu(II) compounds in which divalent copper is located in a compressed octahedral environment, These data are based on results obtained over years in cooperative works between ICMCB and IJS. - Palladium element is known to exhibit various oxidation states, e.g. II to IV, in fluorinated environments. In the case of PdIIF2 , besides the rutile-type form obtained from room pressure reactions, a high-pressure (HP) form had been isolated in reactions conducted in a HP “belt” system around 50 kbar. This HP form was shown to derive from the fluorite type by a rhombohedral distortion of the cubic environment of the cation [1]. A similar structural network has been obtained via a LT route, by mixing Pd(AsF6)2 and CsF in anhydrous HF [2]. A minimum of reciprocal susceptibility occurs around 180 K, a value which is similar to the Néel temperature of HP-PdF2 ( T N = 190 K), as determined by neutron diffraction experiments. Another Pd(II) compound: Pd(AsF6)2, can be obtained in AsF5/aHF superacidic medium either by oxidising metallic palladium as solvated Pd2+ cations or by adding elemental fluorine into a suspension of PdO, from which Pd(AsF6)2 could be isolated. The crystal structure of Pd(AsF6)2 confirms the presence of highly distorted (AsF6)- anions as predicted by vibrational spectroscopy [3]. The network is derived from the LiSbF6 type (ordered ReO3) with ordered vacancies for half of the cationic sites, i.e. Pd0.5□0.5AsF6. In the series of transition-metal difluorides the sequence: fluorite > LT-PdF2 > rutile is followed, and may explain why the LT form is stabilized with respect to the rutile form via a LT process. - In Cu(II)-based fluorides, the crystal structures and magnetic properties of CuFAsF6 and CsCuAlF6, prepared in aHF medium or by solid state reaction respectively, illustrate two rare examples of Cu(II) compounds with a compressed tetragonal geometry of [CuF6]4- octahedra. Both structural networks are composed of 1-dimensional infinite [CuF 3n-5]n chains of [CuF6]4- octahedra sharing opposite corners. Their magnetic behavior can be compared to those of other 1D networks containing Cu(II) in which a non-compensation of magnetic moments occur at low temperature, as also in CrF4 [5]. Acknowledgements – The author is indebted to cooperative programs such as French-Slovenian Proteus Program, Funfluos European Network. References [1] A. Tressaud, G. Demazeau, High Temp. High Press., 16, 303, 1984. [2] Z. Mazej, A. Tressaud, J. Darriet, J. Fluorine Chem. 110, 139 (2001). [3] Z. Mazej, P. Benkič, A. Tressaud, B. Žemva, Europ. J. Inorg. Chem., 1827 (2004). [4] Z. Mazej, I. Arčon, P. Benkič, A. F. Kodre, A. Tressaud, Chem. Eur. J., 10, 5052 (2004). [5] Z. Mazej, J. Darriet, J. Grannec, K. Lutar, A. Tressaud, B. Žemva, J. Fluorine Chem. 99, 25 (1999). 26 L11 FLUORINE FRONTIERS 2024 α-Silyl Carbanions Stabilized by Pentafluoroethyl Groups Berthold Hoge,* Julia Landwehrmann, Bielefeld University, Center for Molecular Materials, Bielefeld, Germany *e-mail: b.hoge@uni-bielefeld.de As early as 1947, GRIGNARD reagents were used by SOMMER et al. to synthesize α-silyl carbanion-equivalent compounds [1]. Since then, various methods have been developed to generate α-silyl carbanions in situ [2][3][4][5]. Due to the instability of these compounds, it has only been possible to structurally characterize α-silyl carbanions in two cases [6][7]. In this lecture, the synthesis of isolable α-silyl carbanions stabilized by pentafluoroethyl groups on the silicon atom will be presented and their reactivity will be discussed. With regard to reactivity, particular attention will be paid to the reaction with carbonyl compounds, based on Peterson olefination. Figure 1: α-Silyl carbanions stabilized by pentafluoroethyl groups. References [1] L. H. Sommer, G. M. Goldberg, J. Gold, F. C. Whitmore, J. Am. Chem. Soc. 1947, 69, 980. [2] D. J. Ager, J. Org. Chem. 1984, 49, 168. [3] K. Itami, K. Mitsudo, J. Yoshida, Tetrahedron Lett. 1999, 40, 5533. [4] D. J. Peterson, J. Org. Chem. 1968, 33, 780. [5] T. Takeda (Ed.) Modern Carbonyl Olefination. Methods and Applications, Wiley-VCH, Weinheim, 2003. [6] T. Kawashima, N. Iwama, R. Okazaki, J. Am. Chem. Soc. 1992, 114, 7598. [7] J. L. Robison, W. M. Davis, D. Seyferth, Organometallics 1991, 10, 3385. 27 Abstracts L12 Fluorochemicals with Uniquely Important Applications in Electronics Robert (Bob) G. Syvret, Ph.D., FACS Fluorine Chemistry and Technology (F2ChemTech) LLC, Allentown, PA USA *e-mail: syvretrg@f2chemtech.com Processing of semiconductor materials that are used in the fabrication of integrated circuits and computer chips is heavily dependent on the use of many different fluorochemical products employed at various critical stages throughout the fabrication lifecycle. For example, WF6 is used for tungsten metal deposition; NF3 and other fluorocarbons are used for chamber cleaning; and many different fluorocarbons, including fluoroalkanes and hydrofluorocarbons are used for various reactive-ion etching steps that collectively create the intricate electronic circuitry on a silicon wafer that results in a computer chip. And the semiconductor industry’s dependence on fluorine technology has never been stronger than it is today. For example, atomic layer deposition, ALD, is a well-known and widely used technology for precision control of atomic layer by layer deposition. The complimentary process, atomic layer etching (ALE), has emerged as a critical enabling technology required for controlled and systematic layer by layer etching of device features as the required dimensions shrink to well-below 10 nm. One area of great need and especially for thermal ALE is the development of new fluorinated materials and methodologies that will improve efficiency, selectivity and self-limiting characteristics while reducing cycle times and collateral damage that is so often the result when plasma-assisted ALE processing is employed. In addition to the “common” fluorochemicals traditionally used in semiconductor materials processing, there currently are several emerging fluorine compounds under development that provide both sustainable and environmentally friendly alternatives to the legacy materials used in semiconductor technology. An overview of fluorochemicals’ importance to the electronics industry including some recent advances in technology development will be highlighted in this presentation. 28 L13 FLUORINE FRONTIERS 2024 Fluorochemicals with Uniquely Important Applications in Electronics Adventures in Xenon- and Mercury-Chemistry with Weakly Coordinating Perfluoroalkoxyaluminate Anions Robert (Bob) G. Syvret, Ph.D., FACS Ingo Krossing,1* Konstantin Kloiber.1 Fluorine Chemistry and Technology (F2ChemTech) LLC, Allentown, PA USA 1 Institute for Inorganic and Analytical Chemistry, Albert-Ludwigs-Universität Freiburg, Germany, Albertstr. *e-mail: syvretrg@f2chemtech.com 21, 79104 Freiburg. Processing of semiconductor materials that are used in the fabrication of integrated circuits and *e-mail: krossing@uni-freiburg.de computer chips is heavily dependent on the use of many different fluorochemical products employed at various critical stages throughout the fabrication lifecycle. For example, WF6 is This lecture will honor the achievements of Boris Zemva and hence report on our own used for tungsten metal deposition; NF3 and other fluorocarbons are used for chamber cleaning; adventures in trying to prepare the seemingly simple ‘naked’ Hg[WCA]2 salt as well as upon and many different fluorocarbons, including fluoroalkanes and hydrofluorocarbons are used for investigating the deelectronation capability of the mixture XeF2 + 2 Li[WCA] to formally give various reactive-ion etching steps that collectively create the intricate electronic circuitry on a 2 LiF, Xe gas and two positive charges (WCA = [ pf]– ([Al(ORF)4]–) or [ alfal]– ([RFO)3Al-F-silicon wafer that results in a computer chip. And the semiconductor industry’s dependence on Al(ORF)3]–) and RF = C(CF3)3). fluorine technology has never been stronger than it is today. For example, atomic layer deposition, ALD, is a well-known and widely used technology for precision control of atomic Hence, the reaction of XeF2 + 2 Li+ in fluorobenzenes xFB (x = 1,2,3) intermediately led to layer by layer deposition. The complimentary process, atomic layer etching (ALE), has radicals, from which the [Xe((C6FxH5-x))]+ salts formed and which subsequently reacted already emerged as a critical enabling technology required for controlled and systematic layer by layer at low temperatures (–40 °C) to the biphenyl radical cation salts shown in Figure 1. The pathway etching of device features as the required dimensions shrink to well-below 10 nm. One area of and intermediates are reported and rationalized as well as the scope of these partially extremely great need and especially for thermal ALE is the development of new fluorinated materials and deelectronating cations like tetrafluorobiphenyl ( E°’ = 1.80 V vs. Fc+/Fc) and methodologies that will improve efficiency, selectivity and self-limiting characteristics while hexafluorobiphenyl ( E°’ = 2.10 V vs. Fc+/Fc) is delineated. reducing cycle times and collateral damage that is so often the result when plasma-assisted ALE processing is employed. The seemingly simple ‘naked’ Hg[WCA]2 salt should be an attractive starting material for further Hg2+ coordination chemistry. Yet, most of the hitherto tested routes to such salts ended In addition to the “common” fluorochemicals traditionally used in semiconductor materials up with the formation of chain-cations [Hgn]2+ (n = 2, 3, 4), which include two 1-coordinated processing, there currently are several emerging fluorine compounds under development that xFB solvents as ingredient. Scope and limits are explained and it is shown that xFB solutions provide both sustainable and environmentally friendly alternatives to the legacy materials used containing the ‘naked’ Hg2+ cation react with the latter already at very low temperature under in semiconductor technology. An overview of fluorochemicals’ importance to the electronics C-H bond activation to give monocations [Hg(C6FxH5-x)]+ and also do activate silicon grease industry including some recent advances in technology development will be highlighted in this based on (Me2SiO)n with formation of the [Hg(Me)]+ cation salts. So, exclude silicon grease! presentation. Figure 1: Final outcome of the delineated reactions. InOx = Innocent Oxidant, e.g. [C10F8]+·. References: All of this work is hitherto unpublished and credits go to the excellent PhD student M.Sc. Chem. Konstantin Kloiber. 29 Abstracts L14 Novel two-dimensional quantum magnets based on Ag(II) Wojciech Grochala,1* Mateusz Domanski,1 Daniel Jezierski,1 Zoran Mazej2 1 Center of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland 2 Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia *e-mail: w.grochala@cent.uw.edu.pl There is an upsurge of interest in Ag(II)-based materials, in particular two-dimensional ones [1]. The focus is on magnetic properties of these systems as Ag(II) is a powerful spin-polarizer which often shows strong antiferromagnetic superexchange (SE) even via fluoride ligands (the least polarizable monoatomic ligands known). Superexchange between Ag(II) and other transition metal cations is also of interest but only very few cations may withstand the oxidizing power of Ag(II). We have recently successfully prepared two novel Ag(II) based systems, AgCoF5 [2] and CuAg(SO4)2 [3]. The first one is characterized by a strong Ag(II)/Co(III) SE with the SE constant of ca. –62 meV, which is similar to the value for pristine AgF2 of –70 meV [1]. Our calculations predict that similar isostructural monoclinic AgAgF5 featuring high-spin Ag(III) could also be prepared and it should host even stronger SE interactions (−100 meV for Ag(II)/Ag(III) and −93 meV for Ag(III)/Ag(III)) [2]. On the other hand, CuAg(SO4)2 shows a two-dimensional [Ag(SO 2– 4)2 ] sublattice (Figure 1) with SE constant of ca. −11.1 meV; here, SE is transmitted via a larger sulphate ligand, just like for AgSO4 [4]. Despite that, SE could be quite strong for some as yet hypothetical members of the M(II)Ag(SO4)2 family (for example ca. −49 meV for M=Ba [3]). While predominant magnetic SE interactions are antiferromagnetic in these compounds, their magnetic properties may be quite complex. CuAg(SO4)2 has recently been postulated to be one of very few systems which host a new form of magnetism called altermagnetism [5]. Figure 1: The two-dimensional [Ag(SO 2– 4)2 ] sublattice of CuAg(SO4)2. References [1] J. Gawraczyński et al., Proc. Nat. Acad. Sci. USA 116(5), 1495-1500, 2019. [2] M. Domański, Z. Mazej, W. Grochala, Chem. Eur. J. 29(62), e202302042, 2023. [3] D. Jezierski, Z. Mazej, W. Grochala, Dalton Trans. , in press 2024. [4] P. J. Malinowski et al., Angew. Chem. Int. Ed. Engl. 49(9), 1683-1686, 2010. [5] H. O. Jeschke, M. Shimizu, I. I. Mazin, Phys. Rev. B 109(22), L220412, 2024. 30 L15 FLUORINE FRONTIERS 2024 Tris(pentafluoroethyl)difluorophosphorane: A Versatile Fluoride Acceptor for Transition Metal Chemistry Prof. Dr. Udo Radius,1 1 Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany *e-mail: udo.radius@uni-wuerzburg.de Fluoride abstraction reactions from different types of transition metal fluoride complexes [LnM−F] using the Lewis acid tris(pentafluoroethyl)difluorophosphorane (C2F5)3PF2[1] to yield cationic transition metal complexes with the weakly coordinating tris(pentafluoroethyl)trifluorophosphate counterion (FAP anion, [(C2F5)3PF3]−) are presented (see Figure 1).[2] Some basic (stereo-electonic) properties of the phosphorane will be discussed as well as NHC adducts of this phosphorane.[3] (C2F5)3PF2 reacts with NHC (= N-Heterocyclic Carbene) nickel fluorides, with titanocene difluoride, and with NHC copper fluorides to yield cationic organometallic complexes with the FAP counterion.[2] First investigations concerning the reactivity of these salts and their application in catalysis will be presented. F F C2F5 F C L 2F5 C nM F + 2F5 P LnM P C2F5 C2F5 C2F5 F F readily available weakly coordinating fluoride acceptor anion Figure 1: Fluoride abstraction from transition metal fluorides with the Lewis acid tris(pentafluoroethyl)difluorophosphorane. References [1] N. Ignat’ev, P. Sartori, J. Fluorine Chem. 2000, 103, 57; N. V. Ignat’ev, J. Bader, K. Koppe, B. Hoge, H. Willner, J. Fluorine Chem. 2015, 171, 36; N. Ignat’ev, Electrochemical Fluorination: A Powerful Tool for the Preparation of Organofluorine Compounds, in: Modern Synthesis Processes and Reactivity of Fluorinated Compounds, (Eds.: H. Groult, F. R. Leroux, A. Tressaud), Elsevier., London, 2016, 71–123; J. Bader, B. Neumann, H.-G. Stammler, N. Ignat’ev, B. Hoge, Chem. Eur. J. 2018, 24, 6975; J. Bader, B. Neumann, H.-G. Stammler, N. Ignat’ev, B. Hoge, J. Fluorine Chem. 2018, 207, 12. [2] S. A. Föhrenbacher, M. J. Krahfuß, L. Zapf, A. Friedrich, N. Ignat’ev, M. Finze, U. Radius, Chem. Eur. J. 2021, 27, 3504; M. Riethmann, S. A. Föhrenbacher, H. Keiling, N. V. Ignat’ev, M. Finze, U. Radius, Inorg. Chem. 2024, 63, 8351. [3] S. A. Föhrenbacher, V. Zeh, M. J. Krahfuss, N. Ignat’ev, M. Finze, U. Radius, Eur. J. Inorg. Chem. 2021, 1941. 31 Abstracts L16 Unusual Fluorine Containing Compounds: from Oxyfluorides and High Potential Oxidizers Sebastian Riedel,1 1 Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany *e-mail: s.riedel@fu-berlin.de In recent years, several unusual fluorinated compounds have been investigated under cryogenic conditions using matrix-isolation spectroscopy in conjunction with quantum-chemical calculations, confirming experimental assignments and providing fruitful information on the stability and properties of such species. Here we will provide new insights into the formation of single oxygen atom coordination by Lewis-acids as well as hypervalent coordinated oxygen atoms. Furthermore, we will show that fluorine atoms are able to undergo heavy atom tunneling processes. Figure 1: Heavy atom tunneling in polyfluorides 32 L17 FLUORINE FRONTIERS 2024 Unusual Fluorine Containing Compounds: Fluorinated aminophospohonates and amino acids with olefinic motif – from Oxyfluorides and High Potential Oxidizers versatile peptidomimetics Sebastian Riedel,1 Henryk Koroniak,1* Marcin Kaźmierczak,1 Katarzyna Koroniak-Szejn,1 Karolina Paszek 1 1 Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany 1 Faculty of Chemistry, Adam Mickiewicz University *e-mail: s.riedel@fu-berlin.de Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland In recent years, several unusual fluorinated compounds have been investigated under cryogenic *e-mail:koroniak@amu.edu.pl conditions using matrix-isolation spectroscopy in conjunction with quantum-chemical calculations, confirming experimental assignments and providing fruitful information on the stability and properties of such species. Here we will provide new insights into the formation Aminophosphonates are compounds showing pronounced and interesting biological activity of single oxygen atom coordination by Lewis-acids as well as hypervalent coordinated oxygen (e.g. are potent drugs against osteoporosis). Especially, considering the acidity and a steric atoms. Furthermore, we will show that fluorine atoms are able to undergo heavy atom tunneling impact, fluorinated phosphonates are frequently used as the non-hydrolysable and stable processes. mimics of naturally occurring phosphates. Similarly fluorine modified carbohydrates (e.g. hyaluronic acid monomers) display interesting biological activity. The search for a new strategies of the synthesis of these compounds is a consequence of the previous studies in our group. Our research has been focused on new approach to a stereocontrolled synthesis of several mono and difluorinated aminophosphonates and later their dipeptides analogues. As a key strategic intermediates for a stereoselective synthesis, aziridine, oxirane or imine derivatives of fluorophosphonates were prepared and their transformations had been studied. Peptidomimetics are compounds derived from peptides obtained by structure modification using unnatural amino acids and/or conformational restraints. Modified fluorinated amino acids are of great interest as the building blocks for the preparation of peptidomimetics. Herein we would like to report the synthesis of fluorinated analogues of amino acids bearing olefinic moiety with the use of the synthetic sequence with Horner-Wadsworth-Emmons reaction as a key reaction. Figure 1: Heavy atom tunneling in polyfluorides Figure 1. Examples of some intermediates used in the fluorophosphonates preparation 33 Abstracts L18 One Of The Smallest Elements Of The Periodic Table, But The Diamond Of Our Life, Element F2 Dr. Dayal T. Meshri,1 Sanjay D. Meshri,2 Professor Elena Shembel,3 Dr. Ritesh Jain,4 Dr. Prakash Iyer5 1 4546 S. Columbia Avenue Tulsa, Oklahoma USA Dr.meshri@yahoo.com 2 2200 S. Utica Place Suite 405 Tulsa, OK USA sanjay@meshri.org 3 Enerize Corporation, Coral Springs, Florida USA eshembel@enerize.com 4 Dow-Houston, Texas USA ritsjain@hotmail.com 5 Inhance Technologies 22008 N. Berwick Drive Houston, TX USA piyer@inhancetechnologies.com The occurrence, discovery, isolation of element fluorine and its contributions to the field of space exploration, refrigeration, surface treatment, dental hygiene, health, agriculture and high-energy density lithium and lithium ion batteries, lubrication etc. will be discussed in this presentation. 34 L19 FLUORINE FRONTIERS 2024 One Of The Smallest Elements Of Rhodium-Mediated C-H and C-F Bond Activation to Access The Periodic Table, But The Diamond Of Our Life, Element F2 Fluorinated Alkene Derivatives Dr. Dayal T. Meshri,1 Sanjay D. Meshri,2 Professor Elena Shembel,3 Thomas Braun,1* Cortney von Hahmann,1 Maria Talavera,1 Soodeh Mollasalehi1 Dr. Ritesh Jain,4 Dr. Prakash Iyer5 1 Department of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany 1 4546 S. Columbia Avenue Tulsa, Oklahoma USA Dr.meshri@yahoo.com *e-mail: thomas.braun@cms.hu-berlin.de 2 2200 S. Utica Place Suite 405 Tulsa, OK USA Useful methods for a metal-mediated derivatization of fluorinated molecules are often based on sanjay@meshri.org C−H or C−F bond activation reactions.[1] In order to make C−F bond cleavage steps feasible, 3 Enerize Corporation, Coral Springs, Florida USA other strong element−fluorine bonds such as H−F or Si−F bonds have to be formed. Thus, at eshembel@enerize.com rhodium, highly reactive Rh(I) species such as [Rh(H)(PEt3)3], [Rh{Si(OEt)3}(PEt3)3] or [Rh(GePh3)(PEt3)3] can serve as suitable tools to induce a C−F bond activation step, but also 4 Dow-Houston, Texas USA C−H bond activation reactions.[2] Stoichiometric studies at the rhodium complexes as well as ritsjain@hotmail.com initial catalytic reactions for the hydrodefluorination, silylation or germylation of olefinic 5 Inhance Technologies 22008 N. Berwick Drive Houston, TX USA precursors will be described (Figure). In another spin-off catalytic cross-coupling reactions piyer@inhancetechnologies.com were developed, which are characterized by an outer-sphere C-C coupling step. The occurrence, discovery, isolation of element fluorine and its contributions to the field of space exploration, refrigeration, surface treatment, dental hygiene, health, agriculture and high-energy density lithium and lithium ion batteries, lubrication etc. will be discussed in this presentation. Figure: A Rh germyl complex for the germylation of a fluorinated olefin. References [1] T. Ahrens, J. Kohlmann, M. Ahrens, T. Braun, Chem. Rev. 2015, 115, 931-972; M. Talavera, T. Braun, Synlett 2020, 31, 1760-1774. [2] M. Talavera, T. Braun T., Chem. Sci. 2022, 13, 1130-1135; M. Talavera, R. Müller, T. Ahrens C. N. von Hahmann, B. Braun-Cula, M. Kaupp, T. Braun, Faraday Discuss. 2019, 220, 328-349; M. Talavera, C. N. von Hahmann, R. Mül er, M. Ahrens, M. Kaupp, T. Braun, T. Angew. Chem. Int. Ed. 2019, 58, 10688-10692; M. Talavera, S. Mollasalehi ,T. Braun, Chem. Sci. 2024, 15, 8472–8477. 35 Abstracts L20 Unusual Reactivity Triggered By Fluorine – From Exotic Complexes To Novel Reaction Mechanisms Przemysław J. Malinowski*,1 Magdalena Grochowska-Tatarczak,1 Michał Jadwiszczak,1 Kacper Koteras,1 Piotr J. Leszczyński1 1 Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw, Poland *e-mail: malin@cent.uw.edu.pl One of the peculiarities of fluorine is that on one hand it is the most reactive element, but on the other, its compounds are often ranked as the most inert. This feature is used to form so-called weakly coordinating anions (WCAs), which are typically perfluorinated species.[1] Their properties render typical cations extraordinarily reactive which opens new possibilities in chemistry. The presentation shows our recent advancements enabled by pairing simple metal cations with the most advanced WCAs. This includes the synthesis of novel, otherwise unstable metal complexes containing exotic ligands like N2 (Fig. 1a)[2] but also noble gas atoms. But salts of WCAs, even those containing simple metal cations can also efficiently catalyze organic reactions, at times according to novel mechanisms (Fig. 1b).[3] Figure 1: a) Crystal structure of Cu+-N2 complex stabilized with perfluorinated alkoxyaluminate; b) Transition state structure of reaction of olefin hydrosilylation catalyzed by Ca2+ cation. . References [1] I. Riddlestone, A. Kraft, J. Schaefer, I. Krossing, Angew. Chem. Int. Ed. , 57 (43), 13982-14024, 2018. [2] J. Willrett, M. Schmitt, M. Sellin, V. Zhuravlev, P. J. Malinowski, I. Krossing, Angew. Chem. Int. Ed. , e202405330, 2024 [3] M. Grochowska-Tatarczak, K. Koteras, K. Kazimierczuk, P. J. Malinowski, Chem. Eur. J., e202401322, 2024. 36 L21 FLUORINE FRONTIERS 2024 Theranostic Applications of Fluorinated Dendrimers Pierangelo Metrangolo Laboratory of Supramolecular and Bio-Nanomaterials (SBNLab), Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, 20131 Milan, Italy *e-mail: pierangelo.metrangolo@polimi.it Janus-type dendrimers (JDs) are dendritic macromolecules bearing two domains of different polarity. A tailored balance between the two portions allows to control their physico-chemical properties, and therefore their functions. The use of fluorinated chains is a powerful tool to increase JDs colloidal stability and influence their self-assembling properties [1]. Moreover, the use of branched fluorinated moieties can be exploited for non-invasive in vivo monitoring by 19F-MRI to develop new theranostic nanosystems [2]. In this lecture, I will show how the balance between a perfluoro- tert-butyl moiety and polyester dendrons of generations 1-3 can strongly affect self-assembling behavior of a family of Fluorinated JDs (FJDs) [3], see Figure 1, and how the final physico-chemical properties can be exploited to synthesize an ionizable fluorinated JD for gene delivery applications [4]. Figure 1: The three fluorinated JDs (Gen. 1 to 3) showed different magnetic properties at 19F-NMR depending on their self-assembly in water media. Acknowledgements: The project INNOVA “Italian network of excellence for advanced diagnosis”, Hub life science - Diagnostica Avanzata (LSH-DA), PNC-E3-2022-23683266 is gratefully acknowledged. References [1] C. Chirizzi, et al. , J. Am. Chem. Soc. , 143, 12253-12260, 2021. [2] M. Rosati, et al. , Macromolecules, 55, 2486-2496, 2022. [3] A. K. Singh, et al. , Macromol. Biosci. , 22, 2200108, 2022. [4] F. Baldelli Bombelli, P. Metrangolo, G. Cavallo, N. Bono, G. Candiani, M. Rosati, G. Pinter Lauria, S. Marcuzzo, Non-Viral Vectors for Gene Therapy. WO2023170543A1. 37 Abstracts L22 Electrochemical Fluorination: Synthesis of Fluorine-Containing Building Blocks Maik Finze,* Nikolai V. Ignat’ev, Leon N. Schneider, Tanja Knuplez, Younes K. J. Bejaoui, Roland Graf Institute of Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), University of Würzburg, Am Hubland, 97924 Würzburg, Germany *e-mail: maik.finze@uni-wuerzburg.de The incorporation of fluorine into molecules and materials typically results in unique properties, which are relevant for applications, e.g. pharmaceuticals, agrochemicals, and energy-related materials [1]. The electrochemical fluorination (ECF, Simons process) is an efficient process for the synthesis of fluorinated molecules [2,3]. Per- and polyfluorinated compounds that are accessible via ECF include CF3SO2N(CF3)2 and CF3SO2N(CF2H)2 [4], FSO2(CF2) n SO2F ( n = 1–3) [5], and (C2F5)3PF2 [6]. Recently, we have adopted the ECF for the preparation of partially fluorinated alkyl triflates, e.g. CF3SO2OCH2F and CF3SO2OCHF2 [7]. The aforementioned fluorinated molecules are versatile building blocks for organic, coordination, and materials chemistry. For example, copper and silver complexes with the bis(trifluoromethyl)amido ligand were established as N(CF3)2-transfer reagents [8] and ionic liquids (ILs) with the [(C2F5)3PF3]– (FAP) anion [2,3,9] or cyclic perfluoroalkylsulfonylimide anions [10] have been developed. References [1] P. Kirsch, Modern Fluoroorganic Chemistry, Weinheim: Wiley-VCH Verlag GmbH & Co. KGaA, 2013. [2] N.V. Ignat’ev, “Electrochemical Fluorination: A Powerful Tool for the Preparation of Organofluorine Compounds” in Modern Synthesis Processes and Reactivity of Fluorinated Compounds, H. Groult, F. Leroux, A. Tressaud, London: Elsevier Inc., 2016. [3] N.V. Ignat’ev, H. Willner, P. Sartori, J. Fluorine Chem. , 130, 1183–1191, 2009. [4] P. Sartori, N. Ignat’ev, S. Datsenko, J. Fluorine Chem. , 75, 157–161, 1995. [5] R. Jüschke, D. Velayutham, P. Sartori, J. Fluorine Chem. , 83, 145–149, 1997. [6] N. Ignat’ev, P. Sartori, J. Fluorine Chem. , 103, 57–61, 2000. [7] T. Knuplez, L.N. Schneider, T. Preitschopf, Y.K.J. Bejaoui, L. Zapf, N. Schopper, K.A.M. Maibom, J.A.P. Sprenger, F. Gehrke, S. Lorenzen, R. Graf, R. Bertermann, I. Fischer, N.V. Ignat’ev, M. Finze, Chem. Eur. J. , 29, e202302701, 2023. [8] L.N. Schneider, E.-M. Tanzer Krauel, C. Deutsch, K. Urbahns, T. Bischof, K.A.M. Maibom, J. Landmann, F. Keppner, C. Kerpen, M. Hailmann, L. Zapf, T. Knuplez, R. Bertermann, N.V. Ignat’ev, M. Finze, Chem. Eur. J. , 27, 10973–10978, 2021. [9] N.V. Ignat’ev, M. Finze, J.A.P. Sprenger, C. Kerpen, E. Bernhardt, H. Wil ner, J. Fluorine Chem. , 177, 46– 54, 2015. [10]Y.K.J. Bejaoui, F. Philippi, H.-G. Stammler, K. Radacki, L. Zapf, N. Schopper, K. Goloviznina, K.A.M. Maibom, R. Graf, J.A.P. Sprenger, R. Bertermann, H. Braunschweig, T. Welton, N.V. Ignat’ev, M. Finze, Chem. Sci. , 14, 2200–2214, 2023. 38 L23 FLUORINE FRONTIERS 2024 High-pressure chemistry and physics of fluorides Dominik Kurzydłowski1* 1 Faculty of Mathematics and Natural Sciences Cardinal Stefan Wyszyński University in Warsaw, 01-938, Warsaw, Poland *e-mail: d.kurzydlowski@uksw.edu.pl Current diamond anvil cell (DAC) techniques enable performing routine measurements on solids compressed to 100 GPa (million atmospheres). At such conditions the pressure-volume work term ( pV) becomes comparable to covalent bond energies therefore considerably affecting the chemistry, structure, and properties of compounds that are otherwise well known and characterized under ambient conditions. In addition, species that are hard to attain or even yet unknown can be stabilized by high pressure. [1,2] Theoretical studies hint at the increased electronegativity and reactivity of fluorine at high pressure (p > 1GPa), and hence the possibility of formation of exotic species, such as NF5, [3] AuF6, [4] or IF8. [5] On the other hand, well known fluorides (e.g. NaMgF3) have been shown to be excellent low-pressure analogues (LPAs) of silicates, which are the major component of rocky planets. [6] In an attempt to better understand the high-pressure reactivity and properties of halogen fluorides, which are archetypical compounds used for testing fundamental chemical concepts (e.g. molecular orbital theory or the VSEPR model) we performed a computational study on the high-pressure behavior of bromine fluorides. [7] We found that at a moderately high pressure of 15 GPa, the bonding preference in the Br/F system should change considerably with BrF3 becoming thermodynamically unstable and two novel compounds emerging as stable species: BrF2 and BrF6. In another study, combining both experiment and calculations, we show that above 30 GPa Na2CuF4 adopts a Th3P4-like structure, and that the high-pressure properties of this polymorph closely mimic those of an analogous structure of Mg2SiO4 – a compound that is predicted to form in the mantle of rocky planets under sub-TPa conditions. [8] References [1] W. Grochala, R. Hoffmann, J. Feng, N. W. Ashcroft, Angew. Chemie Int. Ed. 46, 3620, 2007. [2] L. Zhang, Y. Wang, J. Lv, Y. Ma, Nat. Rev. Mater. 2, 17005. J. Lin, X. Du, M. Rahm, H. Yu, H. Xu and G. Yang, Angew. Chemie Int. Ed., 59, 9155–9162, 2020. [3] D. Kurzydłowski, P. Zaleski-Ejgierd, Sci. Rep. 6, 36049, 2016. [4] J. Lin, S. Zhang, W. Guan, G. Yang, Y. Ma, J. Am. Chem. Soc. 140, 9545, 2018. [5] A. Tressaud, N. Bartlett, J. Solid State Chem. , 2001, 162, 333–340. [6] R. Dutta, E. Greenberg, V. B. Prakapenka, T. S. Duffy, Proc. Natl. Acad. Sci. 116, 19324, 2019. [7] M. H. Dalsaniya, D. Upadhyay, K. J. Kurzydłowski, D. Kurzydłowski, Phys. Chem. Chem. Phys. 26, 1762, 2024. [8] D. Upadhyay, S. B. Pil ai, J. Drapała, Z. Mazej, D. Kurzydłowski, Inorg. Chem. Front. 11, 1882, 2024. 39 Abstracts L24 Chloroimidazolium Deoxyfluorination Reagent with H2F3- Anion as a Sole Fluoride Source Gašper Tavčar1, Jernej Iskra2 1 Department of Inorganic Chemistry and Technology, “Jožef Stefan” Institute, Jamova cesta 39, Ljubljana, Slovenia 2 University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia. *e-mail: jernej.iskra@fkkt.uni-lj.si The selective and efficient introduction of fluorine is still an unresolved challenge. Direct fluorination via the “electrophilic” route has problems with selectivity, as there are usually several reaction sites available. On the other hand, the nucleophilic pathway is a selective process as the reaction site is defined by a substituent. However, the fluoride anion is a difficult nucleophile, and several approaches have recently been developed to overcome the disadvantage of nucleophilic fluorination and provide a general and cost-effective method [1] Fluorination with imidazolium-based fluoride reagents has evolved since the 2000s. The best known members of this reagent family include PhenoFluor [2] and its air-stable successor AlkylFluor, [3] which appear to be the favoured reagents for the deoxyfluorination of phenols and aliphatic alcohols, respectively. The use of dihidrotrifluoride anions as a source of fluorine atoms in NHC-based reagents has been developed as a shelf-stable fluoride source with the properties of a free fluorine reagent. [4] It has been further developed into a renewable fluorinating reagent for the fluorination of various organic substrates (benzyl halides, aliphatic halides, tosylates, mesylates, α-haloketones, a silyl chloride, acyl and sulfuryl chlorides, and a nitroarene).[5] We discuss the use of imidazolium-based reagent 1 for fluorination of substrates containing – OH or P(V)OH groups, such as alcohols, carboxylic acids and phosphates, to convert them to their respective fluorides without additional fluoride sources. We also investigated the mechanism of oxygen transfer to form imidazolone 2. Figure 1. Deoxyfluorination with chloroimidazolium H - 2F3 reagent [1] R. Britton, V. Gouverneur, J.-H. Lin, M. Meanwell, C. Ni, G. Pupo, J.-C. Xiao, J. Hu, Nat. Rev. Methods Primers 1, 47, 2021. [2] P. Tang, W. Wang, T. Ritter, J. Am. Chem. Soc. 133, 11482-11484, 2011. [3] N. W. Goldberg, X. Shen, J. Li, T. Ritter, Org. Lett. 18(23), 6102-6104, 2016. [4] B. Alič, G. Tavčar, J. Fluor. Chem. 192, 141-146, 2016. [5] B. Alič, J. Petrovčič, J. Jelen, G. Tavčar, J. Iskra, J. Org. Chem. 87(9), 5987-5993, 2022. 40 L25 FLUORINE FRONTIERS 2024 Chloroimidazolium Deoxyfluorination Reagent with H2F3- Anion as a Sole Do We Still Need To Determine Crystal Structures Experimentally? Fluoride Source Horst Borrmann Gašper Tavčar1, Jernej Iskra2 retired from Max Planck-Institute for Chemical Physics of Solids, Dresden, Germany 1 Department of Inorganic Chemistry and Technology, “Jožef Stefan” Institute, Jamova cesta 39, Ljubljana, *e-mail: horst.borrmann@cpfs.mpg.de Slovenia 2 University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia. First structural information on LiAuF4 was derived from X-ray powder diffraction data in 1970 *e-mail: jernej.iskra@fkkt.uni-lj.si [1]. A tentative model in monoclinic space group C/ c was suggested and compared to tetragonal KBrF4-type structure. Symmetry of the monoclinic model was further reduced in 1991 based The selective and efficient introduction of fluorine is still an unresolved challenge. Direct on single crystal data [2]. However, in a footnote in 1998 Neil Bartlett and coworkers mentioned fluorination via the “electrophilic” route has problems with selectivity, as there are usually the model in C 2/ c being the correct one [3]. A single crystal selected from this very sample was several reaction sites available. On the other hand, the nucleophilic pathway is a selective used to evaluate single crystal diffractometers suitable for K1 at IJS in 1996. This obviously process as the reaction site is defined by a substituent. However, the fluoride anion is a difficult simple crystal structure proved very challenging for the application labs of all major vendors nucleophile, and several approaches have recently been developed to overcome the involved. The fact that both monoclinic models are still present in major data bases calls for disadvantage of nucleophilic fluorination and provide a general and cost-effective method [1] some clarification. Even more as this confusing information is being incorporated in newer Fluorination with imidazolium-based fluoride reagents has evolved since the 2000s. The best types of data compilations like Materials Project [4]. known members of this reagent family include PhenoFluor [2] and its air-stable successor Clearly a deeper understanding of specific experimental details for this peculiar structure very AlkylFluor, [3] which appear to be the favoured reagents for the deoxyfluorination of phenols likely will help to deal with any challenging case. A quite recent example is demonstrated for and aliphatic alcohols, respectively. The use of dihidrotrifluoride anions as a source of fluorine the metallic delafossite PdRhO2 [5]. atoms in NHC-based reagents has been developed as a shelf-stable fluoride source with the properties of a free fluorine reagent. [4] It has been further developed into a renewable References fluorinating reagent for the fluorination of various organic substrates (benzyl halides, aliphatic [1] R. Hoppe, R. Homann, Z. Anorg. Allg. Chem. , 379, 193 - 198, 1970. [2] U. Engelmann, B.G. Müller, Z. Anorg. Al g. Chem. , 598, 103 - 110, 1991. halides, tosylates, mesylates, α-haloketones, a silyl chloride, acyl and sulfuryl chlorides, and a [3] G.M. Lucier, J.M. Whalen, N. Bartlett, J. Fluorine Chem. , 89, 101 - 104, 1998. nitroarene).[5] [4] A. Jain, S.P. Ong, G. Hautier, W. Chen, W.D. Richards, S. Dacek, S. Cholia, D. Gunter, D. Skinner, G. We discuss the use of imidazolium-based reagent 1 for fluorination of substrates containing – Ceder, K.A. Persson, APL Mater. 1, 011002, 2013. OH or P(V)OH groups, such as alcohols, carboxylic acids and phosphates, to convert them to [5] P. Kushwaha, H. Borrmann, S. Khim, H. Rosner, P.J.W. Moll, D.A. Sokolov, V. Sunko, Yu. Grin, A.P. their respective fluorides without additional fluoride sources. We also investigated the Mackenzie, Cryst. Growth Des. , 17 (8), 4144 - 4150, 2017. mechanism of oxygen transfer to form imidazolone 2. Figure 1. Deoxyfluorination with chloroimidazolium H - 2F3 reagent [1] R. Britton, V. Gouverneur, J.-H. Lin, M. Meanwell, C. Ni, G. Pupo, J.-C. Xiao, J. Hu, Nat. Rev. Methods Primers 1, 47, 2021. [2] P. Tang, W. Wang, T. Ritter, J. Am. Chem. Soc. 133, 11482-11484, 2011. [3] N. W. Goldberg, X. Shen, J. Li, T. Ritter, Org. Lett. 18(23), 6102-6104, 2016. [4] B. Alič, G. Tavčar, J. Fluor. Chem. 192, 141-146, 2016. [5] B. Alič, J. Petrovčič, J. Jelen, G. Tavčar, J. Iskra, J. Org. Chem. 87(9), 5987-5993, 2022. 41 ABSTRACTS Student session Phase Transitions in Compressed Palladium Trifluoride Sylwia Olszewska,1 Deepak Upadhyay,1 Sharad Babu Pillai,1 Kinga Zdun,1 Jakub Drapała,2 Klemen Motaln,3,4 Matic Lozinšek3,4, Dominik Kurzydłowski1* 1 Faculty of Mathematics and Natural Sciences Cardinal Stefan Wyszyński University in Warsaw, 01-938, Warsaw, Poland 2 Faculty of Chemistry, Warsaw University of Technology, 00-664, Warsaw, Poland 3 Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia 4 Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia *e-mail: d.kurzydlowski@uksw.edu.pl Fluorides are model systems for the study of pressure-indcued structural transitions, as well as compression-induced reactivity. [1,2] In particular, transition metal fluorides can exhibit high-pressure transformations involving both electronic and magnetic degrees of freedom. [3] Palladium trifluoride adopts at ambient conditions a distorted ReO3-type structure with two inequivalent Pd sites exhibiting II and IV valency. [4] This charge ordering leads to different electron counts and spin population at both sites ‒ Pd2+ with a d8 count has two unpaired electrons, while Pd4+ (d6) has no unpaired electrons. Recent theoretical investigation suggest that this compound should undergo two consecutive phase transitions at 19 and 57 GPa, [5] a prediction yet to be verified. Moreover, the question whether large compression will force Pd(II)Pd(IV)F6 into a metallic state, or rather a spin-1/2 semiconductor state with genuine Pd3+ cations, is still open. Our Raman measurements indicate that palladium trifluoride retains the ambient pressure R−3 structure up to 41 GPa. Above this pressure a transformation occurs into new phases containing Pd3+ cations therefore exhibiting a crossover from mixed valency (II and IV) to single valency (III). References [1] J. Lin, X. Du, M. Rahm, H. Yu, H. Xu and G. Yang, Angew. Chemie Int. Ed., 59, 9155–9162, 2020. [2] D. Kurzydłowski, S. Kobyakov, Z. Mazej, S. B. Pillai, B. Chakraborty, P. K. Jha, Chem. Commun., 56, 4902–4905, 2020. [3] S. López-Moreno, A. H. Romero, J. Mejía-López, A. Muñoz, Phys. Chem. Chem. Phys. , 18, 33250–33263, 2016. [4] A. Tressaud, N. Bartlett, J. Solid State Chem. , 2001, 162, 333–340. [5] S. Ma, L. Zhao, S. Li, T. Gao, F. Peng, Phys. Chem. Chem. Phys. , 25, 6726–6732, 2023. S1 FLUORINE FRONTIERS 2024 Phase Transitions in Compressed Palladium Trifluoride Sylwia Olszewska,1 Deepak Upadhyay,1 Sharad Babu Pillai,1 Kinga Zdun,1 Jakub Drapała,2 Klemen Motaln,3,4 Matic Lozinšek3,4, Dominik Kurzydłowski1* 1 Faculty of Mathematics and Natural Sciences Cardinal Stefan Wyszyński University in Warsaw, 01-938, Warsaw, Poland 2 Faculty of Chemistry, Warsaw University of Technology, 00-664, Warsaw, Poland 3 Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia 4 Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia *e-mail: d.kurzydlowski@uksw.edu.pl Fluorides are model systems for the study of pressure-indcued structural transitions, as well as compression-induced reactivity. [1,2] In particular, transition metal fluorides can exhibit high-pressure transformations involving both electronic and magnetic degrees of freedom. [3] Palladium trifluoride adopts at ambient conditions a distorted ReO3-type structure with two inequivalent Pd sites exhibiting II and IV valency. [4] This charge ordering leads to different electron counts and spin population at both sites ‒ Pd2+ with a d8 count has two unpaired electrons, while Pd4+ (d6) has no unpaired electrons. Recent theoretical investigation suggest that this compound should undergo two consecutive phase transitions at 19 and 57 GPa, [5] a prediction yet to be verified. Moreover, the question whether large compression will force Pd(II)Pd(IV)F6 into a metallic state, or rather a spin-1/2 semiconductor state with genuine Pd3+ cations, is still open. Our Raman measurements indicate that palladium trifluoride retains the ambient pressure R−3 structure up to 41 GPa. Above this pressure a transformation occurs into new phases containing Pd3+ cations therefore exhibiting a crossover from mixed valency (II and IV) to single valency (III). References [1] J. Lin, X. Du, M. Rahm, H. Yu, H. Xu and G. Yang, Angew. Chemie Int. Ed., 59, 9155–9162, 2020. [2] D. Kurzydłowski, S. Kobyakov, Z. Mazej, S. B. Pillai, B. Chakraborty, P. K. Jha, Chem. Commun., 56, 4902–4905, 2020. [3] S. López-Moreno, A. H. Romero, J. Mejía-López, A. Muñoz, Phys. Chem. Chem. Phys. , 18, 33250–33263, 2016. [4] A. Tressaud, N. Bartlett, J. Solid State Chem. , 2001, 162, 333–340. [5] S. Ma, L. Zhao, S. Li, T. Gao, F. Peng, Phys. Chem. Chem. Phys. , 25, 6726–6732, 2023. 45 Abstracts S2 Preparation and Structural Characterisation of Salts Containing the Pyridine and pentafluoropyridine as ligands in transition metal complexes Unique [ MF3(XeF2)3]+ ( M = Pd, Pt) Adduct Cations Michał J. Jadwiszczak,1 Przemysław J. Malinowski1 Klemen Motaln,1,2,* Matic Lozinšek1,2 1 Centre of New Technologies, University of Warsaw, Banacha 2c, 02-093 Warsaw, Poland 1 Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia 2 Jožef Stefan International Postgraduate School, Jamova cesta 39, Ljubljana, Slovenia *e-mail: ŵ͘ũĂĚǁŝƐnjĐnjĂŬΛĐĞŶƚ͘Ƶǁ͘ĞĚƵ͘Ɖů *e-mail: klemen.motaln@ijs.si Pyridine is a commonly used basic solvent in organic chemistry that can donate coordination bonds via its nitrogen atom. Transition metal complexes with pyridine have been studied for The reactions of XeF2 with Lewis acidic tetra- and pentafluorides has been a subject of interest decades. [1] Replacing hydrogen atoms with five fluorine atoms in pyridine increases steric since the discovery of noble-gas reactivity, where the interaction of Xe with PtF6 resulted in the hindrance and significantly reduces electron density at the nitrogen atom, weakening its Lewis formation of compounds of XeF2 with platinum in either +4 or +5 oxidation states [1,2]. base properties. Consequently, complexes with pentafluoropyridine (PFP) are rare, with only a Investigations of XeF2– M F5 systems have revealed a plethora of compounds with 2:1, 1:1 and few known platinum complexes [2-5], which may act as efficient oligomerization catalysts [5]. 1:2 stoichiometries, which were shown to be ionic species with discrete structures [3,4]. Conversely, crystallographically characterised XeF2– M F4 ( M = Ti, Cr, Mn) adducts display In our research, we successfully synthesized Ag(C + + 5F5N)4 and Ag(C5F5N)3 cations supported considerably greater structural diversity, exhibiting either oligo- or polymeric structures [5–8]. by weakly coordinating alkoxyaluminate anion – [Al(OC(CF3)3)4]-. [6] We extended this In the present work, we report on the synthesis and structural characterisation of research to attempt the synthesis of divalent cation salts containing pentafluoropyridine. [Xe2F3][ M F3(XeF2)3][AsF6]2 ( M = Pd, Pt). The [ M F3(XeF2)3]+ adduct cations are composed of Although most attempts were futile, we successfully obtained a Fe salt (Figure 1). We also octahedrally coordinated M IV centres, with three of the coordinating F atoms provided by synthesized the corresponding pyridine complexes, and all compounds were analyzed using fac- coordinated XeF2 ligands (Figure 1). These unique compounds represent the first example DFT calculations to determine their Lewis acidity (fluorine ion affinity, FIA) and enthalpy of of multiple XeF2 molecules bonded to a single M IV centre as well as the only example where formation. These findings highlight the challenges and potential of pentafluoropyridine in coordination of XeF2 to M IV results in a mononuclear species. Moreover, the [PtF3(XeF2)3]+ coordination chemistry, paving the way for further exploration of its applications in catalysis adduct cation is the first crystallographically characterised case of XeF2 coordination to PtIV. and material science. (a) (b) Figure 1: Crystal structure of [Xe Figure 1: Obtained molecular compound containing Fe(II) cation and 3 pentafluoropyridine 2F3][PtF3(XeF2)3][AsF6]2 (50% probability ellipsoids). molecules: whole molecule (a) and highlighted metal coordination sphere (b) References [1] N. Bartlett, Proc. Chem. Soc. , 218, 1962. References: [2] L. Graham, O. Graudejus, N. K. Jha, N. Bartlett, Coord. Chem. Rev. , 197, 321–334, 2000. [1] R.V. Biagetti, H.M. Haendler, Inorg. Chem. 5 (3), 383–386, 1966. [3] F. O. Sladky, P. A. Bul iner, N. Bartlett, J. Chem. Soc. A, 2179–2188, 1969. [2] M. W. Holtcamp, L. M. Henling, M. W. Day, J. A. Labinger, J. E. Bercaw, Inorg. Chim. Acta 270, 467–478, [4] H. St. A. Elliott, J. F. Lehmann, H. P.A. Mercier, H. D. B. Jenkins, G. J. Schrobilgen, Inorg. Chem. , 49, 1998. 8504–8523, 2010. [3] J. J. Adams, N. Arulsamy, D. M. Roddick, Organometallics 28, 1148–1157, 2009. [5] K. Radan, E. Goreshnik, B. Žemva, Angew. Chem. Int. Ed., 53, 13715–13719, 2014. [4]M. A. Bowring, R. G. Bergman, T. D. Tilley, Organometallics 32 (19), 5266–5268, 2013. [6] K. Lutar, I. Leban, T. Ogrin, B. Žemva, Eur. J. Solid State Inorg. Chem., 29, 713–727, 1992. [5] S. Basu, N. Arulsamy, D. M. Roddick, Organometallics 27, 3659–3665, 2008. [7] K. Lutar, H. Borrmann, B. Žemva, Inorg. Chem. , 37, 3002–3006, 1998. [6] M.J. Jadwiszczak, P.J. Malinowski, Chem. Eur. J. 29, e202202976, 2023. [8] K. Motaln, K. Gurung, P. Brázda, A. Kokalj, K. Radan, M. Dragomir, B. Žemva, L. Palatinus, M. Lozinšek, ACS Cent. Sci. , 2024, doi: 10.1021/acscentsci.4c00815. 46 S3 FLUORINE FRONTIERS 2024 Pyridine and pentafluoropyridine as ligands in transition metal complexes Michał J. Jadwiszczak,1 Przemysław J. Malinowski1 1 Centre of New Technologies, University of Warsaw, Banacha 2c, 02-093 Warsaw, Poland *e-mail: ŵ͘ũĂĚǁŝƐnjĐnjĂŬΛĐĞŶƚ͘Ƶǁ͘ĞĚƵ͘Ɖů Pyridine is a commonly used basic solvent in organic chemistry that can donate coordination bonds via its nitrogen atom. Transition metal complexes with pyridine have been studied for decades. [1] Replacing hydrogen atoms with five fluorine atoms in pyridine increases steric hindrance and significantly reduces electron density at the nitrogen atom, weakening its Lewis base properties. Consequently, complexes with pentafluoropyridine (PFP) are rare, with only a few known platinum complexes [2-5], which may act as efficient oligomerization catalysts [5]. In our research, we successfully synthesized Ag(C + + 5F5N)4 and Ag(C5F5N)3 cations supported by weakly coordinating alkoxyaluminate anion – [Al(OC(CF3)3)4]-. [6] We extended this research to attempt the synthesis of divalent cation salts containing pentafluoropyridine. Although most attempts were futile, we successfully obtained a Fe salt (Figure 1). We also synthesized the corresponding pyridine complexes, and all compounds were analyzed using DFT calculations to determine their Lewis acidity (fluorine ion affinity, FIA) and enthalpy of formation. These findings highlight the challenges and potential of pentafluoropyridine in coordination chemistry, paving the way for further exploration of its applications in catalysis and material science. (a) (b) Figure 1: Obtained molecular compound containing Fe(II) cation and 3 pentafluoropyridine molecules: whole molecule (a) and highlighted metal coordination sphere (b) References: [1] R.V. Biagetti, H.M. Haendler, Inorg. Chem. 5 (3), 383–386, 1966. [2] M. W. Holtcamp, L. M. Henling, M. W. Day, J. A. Labinger, J. E. Bercaw, Inorg. Chim. Acta 270, 467–478, 1998. [3] J. J. Adams, N. Arulsamy, D. M. Roddick, Organometallics 28, 1148–1157, 2009. [4]M. A. Bowring, R. G. Bergman, T. D. Tilley, Organometallics 32 (19), 5266–5268, 2013. [5] S. Basu, N. Arulsamy, D. M. Roddick, Organometallics 27, 3659–3665, 2008. [6] M.J. Jadwiszczak, P.J. Malinowski, Chem. Eur. J. 29, e202202976, 2023. 47 Abstracts S4 Protective Role of Aluminium Against Fluoride Toxicity in THP-1 Hydrosilylation of olefins on highly reactive calcium cation Monocytes Magdalena Grochowska-Tatarczak,1* Kacper Koteras,1 Krzysztof Kazimierczuk,1 Anja Pavlovič,1,2,* Larisa Janžič,3 Lucija Sršen,3 Andreja Nataša Kopitar,3 Przemysław J. Malinowski,1 Maja Ponikvar-Svet1 1 Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland 1 Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia 2 Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia *e-mail: m.grochowska@cent.uw.edu.pl 3 Institute for Microbiology and Immunology, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia Olefin hydrosilylation is a process, in which an addition of the Si-H bond to the multiple C=C *e-mail: anja.pavlovic@ijs.si bond takes place. The organosilicon compounds, which are formed afterward, can be found in Monocytes are ideal targets for the assessment of chemical toxicity due to their crucial role in a wide range of substances, such as adhesives, coatings, and antifoams, to name just a few. the immune system, sensitivity to environmental stressors and ability to reveal systemic Hydrosilylations that are performed at a commercial scale usually rely on precious metal toxicological effects. As precursors of macrophages and dendritic cells, monocytes circulate in catalysts, which can boost their final price by as much as 30%.[1] Therefore, there are ongoing the bloodstream and can respond rapidly to toxic exposures, providing early indicators of efforts towards designing a new class of catalysts, that would be cheap and efficient, but also immune activation and damage. When exposed to toxic substances such as fluoride (F–) and as versatile as possible, hopefully with a low toxicity profile. aluminium (Al), monocytes show changes in viability, cytokine production and oxidative stress markers [1,2]. These responses can be measured quantitatively to assess the extent of toxicity. The pseudobinary calcium salt of a Weakly Coordinating Anion (WCAs), Ca[Al[OC(CF3)3]4]2 There are few studies investigating the toxicity of F– and Al on monocytes/macrophages, but (1) seems to fulfill these criteria. Upon dissolution in 1,2-difluorobenzene, it forms a highly the toxicity of aluminium-fluoride complexes (AlF acidic Ca(C x) formed in aqueous solutions remains 6H4F2)6 2+ complex, with the FIA value comparable to SbF5. Thanks to the totally largely unexplored. perfluorinated surface and in the presence of weakly solvating solvents, the salt has proved to catalyze often demanding hydrosilylations, with sterically-hindered substrates. The key stage, To fill this gap, we investigated and compared the toxicity of F‒, Al and AlFx using THP-1 as confirmed by both 1H NMR monitoring and DFT calculations, is the olefin coordination to monocytes in vitro. The cells were treated for 48 hours with standard solutions of F‒, Al and the calcium cation, which leads to C=C bond polarization, which ensues with the subsequent AlFx at concentrations ranging from 2 to 2000 µM. Flow cytometric analyses and annexin H- abstraction from the silane molecule and its coordination to the olefin-Ca2+ complex V/propidium iodide (PI) assays were used to determine the early and late stages of apoptosis (Figure 1). Quantitative NMR studies, carried out for several hydrosilylation systems give hope and necrosis. The greatest differences in toxicity were observed a 2000 µM concentration for developing a new class of catalysts, which can exhibit unique properties in a weakly (Figure 1). F‒ showed the highest toxicity, while Al showed the lowest toxicity. The presence solvating environment. [2] of Al appears to attenuate the toxicity of F– due to the formation of AlFx. Figure 1: Hydrosilylation pathway for a propene/triethylsilane model system catalyzed by (1). TS denotes the transition state, in which alkyl anion is formed, binding eventually to the Figure 1: Percentage (%) of apoptotic and necrotic cells after 48 h stimulation with 2000 µM olefin-Ca2+ complex. F‒, Al and AlFx standards. The values are given as mean ± SD. References [1] L.D. Almeida, H. Wang, X. Cui, M. Beller, Angewandte Chemie International Edition, 60 (2), (550-65), References 2020. [2] M. Grochowska-Tatarczak, K. Koteras, K. Kazimierczuk, P.J. Malinowski, Chemistry – A European Journal, [1] S. Zhu, W.Wei, Front. Immunol. , 15, 1394161, 2024. e202401322, 2024 [2] J.D. Masson, G. Badran, M.A. Domdom, et al., Sci. Rep. , 13, 3198, 2023. 48 S5 FLUORINE FRONTIERS 2024 Hydrosilylation of olefins on highly reactive calcium cation Magdalena Grochowska-Tatarczak,1* Kacper Koteras,1 Krzysztof Kazimierczuk,1 Przemysław J. Malinowski,1 1 Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland *e-mail: m.grochowska@cent.uw.edu.pl Olefin hydrosilylation is a process, in which an addition of the Si-H bond to the multiple C=C bond takes place. The organosilicon compounds, which are formed afterward, can be found in a wide range of substances, such as adhesives, coatings, and antifoams, to name just a few. Hydrosilylations that are performed at a commercial scale usually rely on precious metal catalysts, which can boost their final price by as much as 30%.[1] Therefore, there are ongoing efforts towards designing a new class of catalysts, that would be cheap and efficient, but also as versatile as possible, hopefully with a low toxicity profile. The pseudobinary calcium salt of a Weakly Coordinating Anion (WCAs), Ca[Al[OC(CF3)3]4]2 (1) seems to fulfill these criteria. Upon dissolution in 1,2-difluorobenzene, it forms a highly acidic Ca(C6H4F2)6 2+ complex, with the FIA value comparable to SbF5. Thanks to the totally perfluorinated surface and in the presence of weakly solvating solvents, the salt has proved to catalyze often demanding hydrosilylations, with sterically-hindered substrates. The key stage, as confirmed by both 1H NMR monitoring and DFT calculations, is the olefin coordination to the calcium cation, which leads to C=C bond polarization, which ensues with the subsequent H- abstraction from the silane molecule and its coordination to the olefin-Ca2+ complex (Figure 1). Quantitative NMR studies, carried out for several hydrosilylation systems give hope for developing a new class of catalysts, which can exhibit unique properties in a weakly solvating environment. [2] Figure 1: Hydrosilylation pathway for a propene/triethylsilane model system catalyzed by (1). TS denotes the transition state, in which alkyl anion is formed, binding eventually to the olefin-Ca2+ complex. References [1] L.D. Almeida, H. Wang, X. Cui, M. Beller, Angewandte Chemie International Edition, 60 (2), (550-65), 2020. [2] M. Grochowska-Tatarczak, K. Koteras, K. Kazimierczuk, P.J. Malinowski, Chemistry – A European Journal, e202401322, 2024 49 Abstracts S6 Novel XeII−N-bonded compounds derived from cyanogen Erik Uran,1,2* Kristian Radan,1 Miha Virant,1 Mirela Dragomir,1,2 Matic Lozinšek1,2 1 Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia 2 Jožef Stefan International Postgraduate School, Jamova cesta 39, Ljubljana, Slovenia *e-mail: Erik.Uran@ijs.si Compounds containing XeII−N bond can be synthesized by reactions of Lewis acidic xenon(II) derivatives such as [XeF]+ and [XeOTeF5]+ with oxidatively resistant nitrogen bases [1–6]. However, only one xenon(II) moiety could be coordinated to the corresponding Lewis base. To investigate the possibility of bonding multiple xenon(II)-based moieties to a polytopic nitrogen Lewis base, the reaction between the simplest ditopic nitrogen base cyanogen and [XeF][AsF6] was carried out at low temperatures. This led to the isolation of [FXeNCCNXeF][AsF6]2 in which a nearly linear cation [FXeNCCNXeF]2+ (Figure 1a) has the longest Xe−N and the shortest Xe−F bonds in the series of crystallographically characterized [R≡NXeF]+ adduct cations [4,5]. The [FXeNCCNXeF][AsF6]2 compound undergoes a formal fluoride rearrangement, similar to the one observed in [F3SNXeF][AsF6] [7], yielding [XeNC(F)C(F)NXe][AsF6]2 (Figure 1b), which features a unique C=N−Xe bonding modality. This compound is remarkably stable at room temperature and could be used as a suitable starting material for further studies of xenon–nitrogen chemistry due to the presence of σ-holes on the XeII atoms. This was demonstrated by the low-temperature synthesis of its acetonitrile adduct, [CH3CN···XeNC(F)C(F)NXe···NCCH3][AsF6]2 (Figure 1c), which is, in addition to [F4SNXe···NSF3][AsF6] [8], the only other crystallographically characterized example of an N−Xe−N linkage. Figure 1: Compounds isolated from NCCN–[XeF][AsF6] system. In a) and c) the anions are omitted for clarity. References [1] A. A. A. Emara, G. J. Schrobilgen, J. Chem. Soc., Chem. Commun. , (21), 1644–1646, 1987. [2] A. A. A. Emara, G. J. Schrobilgen, J. Chem. Soc., Chem. Commun. , (4), 257–259, 1988. [3] G. J. Schrobilgen, J. Chem. Soc., Chem. Commun. , (22), 1506–1508, 1988. [4] B. Fir, M.S. Thesis, McMaster University, 1999. [5] G. L. Smith, H. P. A. Mercier, G. J. Schrobilgen, Inorg. Chem. , 46 (4), 1369–1378, 2007. [6] A. N. Toraman, L. Fischer, A. Pérez-Bitrián, A. Wiesner, K. F. Hoffmann, S. Riedel, Chem. Commun. , 60 (13), 1711–1714, 2024. [7] G. L. Smith, H. P. A. Mercier, G. J. Schrobilgen, J. Am. Chem. Soc. , 131 (21), 7272–7286, 2009. [8] G. L. Smith, G. J. Schrobilgen, Inorg. Chem. , 48 (16), 7714–7728, 2009. 50 S7 FLUORINE FRONTIERS 2024 Trifluoromethylthiolation: A Strategy for Hydrophobic Peptide Development Jure Gregorc,1,2 Nathalie Lensen,2 Gregory Chaume,2 Thierry Brigaud,2 Jernej Iskra1* 1 Chair of Organic Chemistry, FCCT, University of Ljubljana, 113 Večna Pot, 1000 Ljubljana, Slovenia 2 CY Cergy Paris Université, BioCIS, 5 mail Gay-Lussac, 95000 Cergy Pontoise, France *e-mail: jernej.iskra@fkkt.uni-lj.si The incorporation of fluorinated motifs has become an essential strategy in the pharmaceutical and agrochemical industries in recent decades. In addition, the integration of fluorine atoms into peptides often leads to improved metabolic stability, increased side-chain hydrophobicity and membrane permeability, as well as stabilization of the desired secondary structures [1]. Due to the rapidly growing significance of peptide therapeutics, the synthesis of diverse fluorinated amino acids (F-AAs) in enantiomerically pure form and their selective incorporation into peptides represents an important area of innovation. Most reported F-AAs are either monofluorinated or consist of the trifluoromethyl group [2]. However, other fluorinated groups, especially in combination with chalcogen atoms, are still largely unexplored in the peptide arena. The trifluoromethylthio group (CF3S–) is particularly intriguing due to its high lipophilicity parameter, a strong electron-withdrawing effect and a favorable pharmacological profile [3]. Therefore, the synthesis of trifluoromethylthiolated amino acids and their incorporation into peptides is a promising strategy to improve the bioavailability of peptide-based drugs. We will highlight the development of a method for direct trifluoromethylthiolation of aromatic AAs such as tyrosine (Tyr) and tryptophan (Trp) and their related monoamine derivatives (Scheme 1). This strategy has also been applied for the selective late-stage functionalization of Trp-containing peptides and the trifluoromethylthiolated building blocks have been successfully used in the solid-phase peptide synthesis of endomorphin-based neuropeptides. Scheme 1: Direct trifluoromethylthiolation of aromatic AA residues. References [1] A. A. Berger, J.-S. Völler, N. Budisa, B. Koksch, Acc. Chem. Res. , 50, 2093-2103, 2017. [2] M. Zhou, Z. Feng, X. Zhang, Chem. Commun. , 59, 1434-1448, 2023. [3] X.-H. Xu, K. Matsuzaki, N. Shibata, Chem. Rev. , 115, 731-7364, 2015. 51 Abstracts S8 Carboxylic Acids to Acyl Fluorides: An Easy Access for Amides and Esters Jan Jelen,1 Griša Prinčič,2 Nina Cankar,1,2 Jernej Iskra,2 Gašper Tavčar1* 1 Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia 2 Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia *e-mail: gasper.tavcar@ijs.si Fluorine plays a detrimental role in organic chemistry as it imparts unique properties to organic compounds. Not only is it a key component in modern pharmaceuticals and drug design, fluorine also finds application among synthetic chemistry. Acyl fluorides, a carboxylic acid derivatives, are prominent stable synthetic intermediates due to their superior reactivity/stability profile compared to other acid derivatives such as acyl chlorides. Accordingly, they are regarded as easy-to-handle and valuable reagents used as acyl sources. Acyl fluorides have been successfully employed in synthesis of amides, esters, and even in solid-phase peptide synthesis [1,2]. Amides and esters, commonly present motifs in biologically-active compounds, are accessed from carboxylic acids by use of traditional coupling methods that often suffer from limited applicability, high reagent prices, use of toxic chemicals, poor atom economy and impractical procedures. Our research focuses on the development of carboxylic acid deoxyfluorination protocol for acyl fluoride synthesis with an easy-to-handle, cost-effective reagent previously reported by our group [3]. Furthermore, this will provide a new, simple method for accessing amides and esters (Figure 1). via O R F Deoxyfluorination Easy access to amides and esters Acyl Fluorides moisture insenstitive operationally-friendly O great reactivity/stability profile O O and R OH Traditional coupling methods R NR2 R OR Carboxylic Acids not generally applicable use costly reagents Amides Esters side product formation problems with purification air-/moisture-sensitive poor atom economy Our research Achievements i-Pr i-Pr mild conditions DIPEA N N O O O F MeCN, rt, 2h F Cl i-Pr i-Pr F F 98% O O H 98% 89% 82% 2F3 amide synthesis Key points: O pyrrolidine, DIPEA Cost-effective reagent N MeCN, rt, 4h measured kinetics second order rate law 96% Simple reagent preparation reaction profile obtained Acyl fluoride synthesis methyl esterification O O DIPEA Amidation/Esterification protocol O MeOH, rt, 2h O 1 Mild ambient conditions H NMR 1H NMR Figure 1: Deoxyfluorination of carboxylic acids to acyl fluorides for access of amides/esters. References [1]. Y. Ogiwara, N. Sakai, Angew. Chem. Int. Ed. , 59 (2), 574-594, 2020. [2] C.Bonnefoy et al . , Eur. J. Org. Chem. , 27 (18), e202400142, 2024 [3] G. Prinčič, B. Omahen, J. Jelen, E. Gruden, G. Tavčar, and J. Iskra, J. Org. Chem. , 89 (15) 10557–61, 2024 52 FLUORINE FRONTIERS 2024 Carboxylic Acids to Acyl Fluorides: An Easy Access for Amides and Esters Jan Jelen,1 Griša Prinčič,2 Nina Cankar,1,2 Jernej Iskra,2 Gašper Tavčar1* 1 Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia 2 Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia *e-mail: gasper.tavcar@ijs.si Fluorine plays a detrimental role in organic chemistry as it imparts unique properties to organic compounds. Not only is it a key component in modern pharmaceuticals and drug design, fluorine also finds application among synthetic chemistry. Acyl fluorides, a carboxylic acid derivatives, are prominent stable synthetic intermediates due to their superior reactivity/stability profile compared to other acid derivatives such as acyl chlorides. Accordingly, they are regarded as easy-to-handle and valuable reagents used as acyl sources. Acyl fluorides have been successfully employed in synthesis of amides, esters, and even in solid-phase peptide synthesis [1,2]. Amides and esters, commonly present motifs in biologically-active compounds, are accessed from carboxylic acids by use of traditional coupling methods that often suffer from limited applicability, high reagent prices, use of toxic chemicals, poor atom economy and impractical procedures. Our research focuses on the development of carboxylic acid deoxyfluorination protocol for acyl fluoride synthesis with an easy-to-handle, cost-effective reagent previously reported by our group [3]. Furthermore, this will provide a new, simple method for accessing amides and esters (Figure 1). via O R F Deoxyfluorination Easy access to amides and esters Acyl Fluorides moisture insenstitive operationally-friendly O great reactivity/stability profile O O and R OH Traditional coupling methods R NR2 R OR Carboxylic Acids not generally applicable use costly reagents Amides Esters side product formation problems with purification air-/moisture-sensitive poor atom economy Our research Achievements i-Pr i-Pr mild conditions DIPEA N N O O O F MeCN, rt, 2h F Cl i-Pr i-Pr F F 98% O O H 98% 89% 82% 2F3 amide synthesis Key points: O pyrrolidine, DIPEA Cost-effective reagent N MeCN, rt, 4h measured kinetics second order rate law 96% Simple reagent preparation reaction profile obtained Acyl fluoride synthesis methyl esterification O O DIPEA Amidation/Esterification protocol O MeOH, rt, 2h O 1 Mild ambient conditions H NMR 1H NMR Figure 1: Deoxyfluorination of carboxylic acids to acyl fluorides for access of amides/esters. References [1]. Y. Ogiwara, N. Sakai, Angew. Chem. Int. Ed. , 59 (2), 574-594, 2020. [2] C.Bonnefoy et al . , Eur. J. Org. Chem. , 27 (18), e202400142, 2024 [3] G. Prinčič, B. Omahen, J. Jelen, E. Gruden, G. Tavčar, and J. Iskra, J. Org. Chem. , 89 (15) 10557–61, 2024 Notes FLUORINE FRONTIERS 2024 Notes FLUORINE FRONTIERS 2024 Notes FLUORINE FRONTIERS 2024