Induced crystallization of polymeric Cd(II)-DMPYS assemblies (DMPYS=4,6-dimethyl-pyrimidine-2-thiolato): synthesis and chaining structures of α- and β-[Cd(DMPYS)2]n

The reaction product of cadmium acetate dihydrate with 4,6-dimethyl-2-pyrimidinethiol (DMPYSH) in ethanol solubilizes by stirring with DMSO {(CH3)2SO} or ammonium diethyl dithiophosphate affording the title compounds α-(1) and β-[Cd(DMPYS)2]n (2). The slow evaporation of the ethanolic solutions allows the suitable crystallization of both polymers and their X-ray diffraction analysis. The complexes 1 and 2 crystallize in the space groups P21/c and Pca21, assembling polymeric, single chains along the crystallographic axis a (1) and b (2). The cadmium centers achieve a distorted octahedral coordination in the whole lattice with the support of four (in 1) and three (in 2) DMPYS molecules. Although in both compounds the anionic ligand DMPYS− realizes μ-S and chelating S,N(ring) bonds, in 2 the bridging S-bonds are singly strengthened by two bidentate bridging bonds of the pyrimidine N-atoms. The polymeric lattice of both compounds is unknown up to date, and probably is matured by the slow splitting of the chelating DMSO and ammonium diethyl dithiophosphate from de Cd coordination sphere of the primary insoluble complexes.