Synthesis, crystal structures and spectroscopic properties of a trinuclear Cusub3(HL)sub2(NOsub3)sub2(Hsub2O)(CHsub2CHsub2OH) complex and a Mn(HL)(CHsub3COO)subn polymer with Hsub3L = N,N'-(2-hydroxypropane-1,3-diyl)-bis-(salicylaldimine)