Crystal structures of 2,2′-bipyridine adducts of two cadmium O-alkyl dithiocarbonates: Rationalisation of disparate coordination geometries based on different crystal packing environments

Abstract

Two distinct coordination geometries are found in the structures of Cd(S2COR)2(2,2′-bipyridine). For R = CH 2CH2OCH3 (1) a N2S2 donor set defines a distorted tetrahedral geometry for cadmium as the xanthate ligands adopt a monodentate coordination mode. By contrast, a N 2S3 donor set is found in the structure where R is butyl (2) as one of the xanthate ligands is chelating. An analysis of the crystal structures shows that both lattices feature extensive C-H...π interactions and that in (1) there are C-H...O interactions that are not present in (2). In (2) there are π...π interactions that are absent in (1). A qualitative argument based on crystal packing considerations is proposed to explain the differences in molecular structures.