Short communication Synthesis and Characterization of Co(II) Complexes of N-Thiophosphorylated Thioureas RC(S)NHP(S)(O/Pr)2 (R = Me2N, 2-MeC6H4NH, 2,6-Me2C6H3NH, 2,4,6-Me3C6H2NH) Maria G. Babashkina,1 Damir A. Safin,1* Michael Bolte2 and Axel Klein1 1 Institut für Anorganische Chemie, Universität zu Köln, Greinstrasse 6, D-50939 Köln, Germany 2 Institut für Anorganische Chemie J.-W.-Goethe-Universität, Frankfurt/Main, Germany * Corresponding author: E-mail: damir.safin @ksu.ru Received: 24-08-2009 Abstract Reaction of the potassium salts of N-thiophosphorylthioureas RC(S)NHP(S)(Oi'Pr)2 (R = Me2N, HL1; 2-MeC6H4NH, HL11; 2,6-Me2C6H3NH, HL111; 2,4,6-Me3C6H2NH, HLIV) with Co(II) cations in aqueous EtOH leads to the comp4exes [Co(LI-IV-5,5')2] ([CoLI-IV2]). The structures of the complexes were studied by IR, UV-Vis spectroscopy and microanalysis. The crystal and molecular structure of [CoLI2] was elucidated by single crystal X-ray diffraction. The metal center is found in a tetrahedral S4 environment formed by the C=S and P=S sulfur atoms of two deprotonated ligands LI. Magnetic properties of [CoLI2] were also investigated. Keywords: Cobalt(II), crystal structure, N-thiophosphorylthiourea, magnetic properties 1. Introduction Phosphorylated amides and ureas, and their thioana-logs of the general formula RC(X)NHP(Y)R'2 (X, Y = O, S) form fairly stable coplexes with a series of double-charged metal ions, in particular, with Co(II).1 The presence of (thio)carbonyl and (thio)phosphoryl groups and of a relatively acidic proton in molecules of V-(thio)-phosphorylated (thio)ureas and (thio)amides predetermines the possibility of chelating coordination of these li-gands through the sulfur and oxygen donor centers with the formation of a stable six-membered chelate ring.2,3 Recent progress in the synthesis and characterization of metal phosph(on)ate compounds has been driven by the need to understand the novel physical properties and their interesting magnetic, catalytic and ionexchange properties.4-8 Thiophosphorylated thioamides RC(S)NHP(S)R'2 and thioureas R1R2NC(S)NHP(S)R'2 have long attracted attention of researchers due to their ability to form stable complexes with IB, IIB, and VIIIB group transition metal cations. These compounds and their complexes exhibit antiviral activity.9 Herein we describe Co(II) complexes of N-thiophosp-horylated thioureas RC(S)NHP(S)(OiPr)2 (R = Me2N, 2-MeC6H4NH, 2,6-Me2C6H3NH, 2,4,6-Me3C6H2NH). The data presented is a continuation of investigations devoted to the structures and magnetic properties of Co(II) complexes with N-(thio)phosphorylthioamides and thioureas.10-21 2. Experimental N-Thiophosphorylated thioureas HLI-IV were prepared according to previously described techniques.21-23 The complex [CoLI2] was prepared according to the previously described method.21 2. 1. Synthesis of [CoLII-IV2] A suspension of HLIIIV (0.768, 1.038, 1.080 or 1.122 g, respectively; 3 mmol) in 96% aqueous EtOH (20 mL) was mixed with an 96% aqueous EtOH solution of KOH (0.185 g, 3.3 mmol). An aqueous (20 mL) solution of Co(NO3)2 x 6H2O (0.582 g, 2 mmol) was added dropwise under vigorous stirring to the resulting potassium salt. The mixture was stirred at room temperature for a further 3 h and left overnight. The resulting complex was extracted with CH2Cl2, washed with water and dried with anhydrous MgSO4. The solvent was then removed in vacuo. A precipitate was isolated from a CH2Cl2 solution by slowly adding n-hexane. [CoL"2]. Yield 0.889 g (79%), green viscous oil. IR: v 602 (P=S), 1002 (POC), 1569 (SCN), 3283 (NH) cm1. UV-Vis Amax (e, mol1 dm3 cm-1): 559 (302), 608 (327), 670 (163) nm. Anal. Calcd for C28H44CoN4O4P2S4: C 44.76, H 5.96, N 7.39. Found: C 44.85, H 5.91, NT 7.47. [CoLm2]. Yield 1.072 g (92%), green viscous oil. IR: v 599 (P=S); 1011 (POC); 1558 (SCN); 3299 (NH) cm-1. UV-Vis Amax (e, mol-1 dm3 cm-1): 567 (294), 602 (339), 661 (157) nm. Anal. Calcd for C30H48CoN4O4P2S4: C 46.32, H 6.22, N 7.20. Found: C 46.40, H 6.17, N 7.141. [CoLIV2]. Yield 1.051 g (87%), green viscous oil. IR: v 606 (P=S); 998 (POC); 1549 (SCN); 3270 (NH) cm-1. UV-Vis Amax (e, mol-1 dm3 cm-1): 562 (292), 611 (337), 672 (165) nm. Anal. Calcd for C32H52CoN4O4P2S4: C 47.69, H 6.50, N 6.95. Found: C 47.782, H 6.61, N 7202. UK; fax: (+44) 1223-336-033; or e-mail: deposit @ ccdc.cam.ac.uk. 3. Results and Discussion Complexes [CoLII-IV2] were prepared by the following procedure: the corresponding ligand was converted into the potassium salt and followed by reaction with Co(NO3)2 in aqueous EtOH (Scheme 1). The compounds [CoLII-IV2] are viscous oils, which are soluble in most polar solvents. R - Me;N (hl1. |CoLl3]>; 2-MeC,,HjNH (HL11, jC«Ll!,|); 2. 2. Physical Measurements Infrared spectra (Nujol) were recorded with a Spe-cord M-80 spectrometer in the range 400-3600 cm-1. Electronic absorption spectra of CH2Cl2 solutions were recorded in the range 200-900 nm on a Perkin-Elmer Lambda 35 spectrophotometer. Magnetic susceptibility measurements were performed on MPMS-5 Quantum Design instrument in the temperature range 1.9-300 K and field range 0-5 T using polycrystalline samples of [CoLI2]. Elemental analyses were performed on a Perkin-Elmer 2400 CHN microanalyzer. 2. 3. Crystal Structure Determination and Refinement The X-ray data were collected on STOE IPDS-II diffractometer with graphite-monochromatized Mo-Ka radiation generated by fine-focus X-ray tube operated at 50 kV and 40 mA. The images were indexed, integrated and scaled using the X-Area data reduction package.24 Data were corrected for absorption using the PLATON program.25 The structure was solved by direct method using the SHELXS-97 program26 and refined on F2 with full-matrix least-squares using SHELXL-97.27 CCDC 692850 contains the supplementary crystal-lographic data for [CoLI2]. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/re-trieving.html, or from the Cambridge Crystallograp-hic Data Centre, 12 Union Road, Cambridge CB2 1EZ, Scheme 1 The IR spectra of [CoLII-IV2] exhibit bands for the P=S group of the anionic forms LII-IV at 599-606 cm-1. There is also an intense band at 1549-1569 cm-1 corresponding to the conjugated SCN fragment. This fact confirms unequivocally the complex formation. Furthermore broad intense bands were observed for the POC group at 998-1011 cm-1. This confirms the conservation of the structure of the ligands in the obtained complexes. There is no band for the PNH group, which testifies the deproto-nated form of the ligands. The band for the arylNH group was found at 3270-3299 cm-1. In the UV-Vis spectra of [CoLII-IV2] in CH2Cl2 solution there is a structured absorption with maxima at 559-567 (emax 292-302 mol-1 dm3 cm-1), 602-611 (emax 327-339 mor1 dm3 cm-1), and 661-672 (emax 157-165 mol-1 dm3 cm-1) nm. The band corresponds to a transition from the ground state 4A2 to the 4T1(P) state. The fine structure is caused by the spin-orbital interaction as a result of which, first, there is a splitting of the state 4T1(P) and, second, there are resolved transitions in the next doublet states with the same intensity. Other possible transitions, namely 4A2 ^ 4T2 and 4A2 ^ 4T1(F) are outside the visible area. The UV-data confirm the tetrahedral environment of the Co(II) cation in [CoLII-IV2].13-15 The variable temperature magnetic susceptibility data for the crystalline sample of [CoLI2] were measured in the temperature range 1.9-300 K with an applied field of 0.1 T. The temperature dependence of the magnetic susceptibility (xM), the reciprocal magnetic susceptibility (XM-1), and the product xMT are shown in Figure 1. o J £ o N 1,0 0,6 0,4 0,2 0,0 o 0 jrtfft1 ^□□□□□oljou dooodd _ ' § J? ii>o S rV 81 y J h 5 so o" „o" - 3 fl £ jû ~ ■w / - W š 30 0 . ✓ - 0 50 [00 150 250 300 - T (K) 1 1 1 30000000000000000 ....... 3,4 3,2 3,0 2,8 2,6 2,4 2,0 o 3 0 50 100 150 200 250 300 T