Supramolecular architectures based on 6-purinethione complexes

In this work we have isolated and characterized by X-ray diffraction two complexes of two metal ions, Cu(I) and Cd(II), with 6-purinethiones as ligands. The structures of these complexes show the metal ions coordinated to 6-mercaptopurine (6-MPH) and 6-thioguanine (6-ThioGH) via S6 in a monodentate fashion and N7–S6 as a chelate ligand, respectively. The compounds show significant differences in the coordination modes and different nuclearity, leading to the formation of mononuclear and tetranuclear structures. Both compounds show an extended one dimensional supramolecular network via self-complementary intermolecular N9(H)⋯N3 hydrogen bonding interactions for two adjacent 6-MPH, and a ribbon like disposition of the complexes by means of pairs of symmetry-related N2(H)⋯N3 hydrogen bonding interactions between two adjacent 6-ThioGH.