Crystal structures of {μ2-N,N′-bis[(pyridin-3-yl)methyl]ethanediamide}tetrakis(dimethylcarbamodithioato)dizinc(II) dimethylformamide disolvate and {μ2-N,N′-bis[(pyridin-3-yl)methyl]ethanediamide}tetrakis(di-n-propylcarbamodithioato)dizinc(II)

Abstract

The title structures, [Zn2(C3H6NS2)4(C14H14N4O2)]·2C3H7NO (I) and [Zn2(C7H14NS2)4(C14H14N4O2)] (II), each feature a bidentate, bridging bipyridyl-type ligand encompassing a di-amide group. In (I), the binuclear compound is disposed about a centre of inversion, leading to an open conformation, while in (II), the complete molecule is completed by the application of a twofold axis of symmetry so that the bridging ligand has a U-shape. In each of (I) and (II), the dithiocarbamate ligands are chelating with varying degrees of symmetry, so the zinc atom is within an NS4 set approximating a square-pyramid for (I) and a trigonal-bipyramid for (II). The solvent dimethylformaide (DMF) molecules in (I) connect to the bridging ligand via amide-N—H...O(DMF) and various amide-, DMF-C—H...O(amide, DMF) interactions. The resultant three-molecule aggregates assemble into a three-dimensional architecture via C—H...π(pyridyl, chelate ring) interactions. In (II), undulating tapes sustained by amide-N—H...O(amide) hydrogen bonding lead to linear supramolecular chains with alternating molecules lying to either side of the tape; no further directional interactions are noted in the crystal