Self-assembly of copper(I) and silver(I) complexes with square-grid and channel structures

Copper(I) and silver(I) complexes of 2-[bis(methylsulfanyl)methylene]propanedinitrilel (bmmp), [Cu(bmmp)(2)]ClO(4) 1 and [Ag(bmmp)(2)]ClO(4) 2, have been prepared and their molecular structures determined by X-ray crystallography. The network topology of bmmp is found to depend on the metal-ion stereochemical preference. In 1 the copper(I) ion prefers a tetrahedral co-ordination geometry comprising four nitrogen atoms from four different bmmp molecules and each bmmp in turn bridges two copper(I) centres leading to a square-grid arrangement of alternating metal cations and organic ligands. In 2, by contrast, the silver(I) ion involves an elongated octahedral environment with four N atoms forming a basal plane and two thioether S atoms occupying the axial positions; each bmmp acts as a non-chelating tridentate ligand bridging three metal centres, resulting in a three-dimensional channel structure. The influence of the metal-ion stereochemical preference on the co-ordination networks of bmmp is discussed.