Strong N–H⋯N hydrogen bonds and weak N–H⋯S C interactions in controlling the structure of the co-crystals of dithiooxamide with nitrogen heterocycles

Abstract

A series of co-crystals of dithiooxamide (dtox) with azaheterocycles 1–6 (1 = 4,4′-dipyridyl, 2 = 1,2-bis(4-pyridyl)ethane, 3 = 2,7-diazapyrene, 4 = 1,4-diazabicyclo[2.2.2]octane, 5 = 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane, 6 = 1,10-phenanthroline) were prepared and their structures were studied by X-ray crystallography. The structures of 1·dtox–5·dtox are characterized by infinite 1D assemblies of the alternating component molecules linked by the N–H⋯N hydrogen bonds whereas in the case of 62·dtox, formation of heterotrimers was observed. In the case of 1·dtox–5·dtox the dtox molecules are arranged into pleated or planar tapes by weak N–H⋯S interactions with H⋯S distances in the range of 2.80–3.15 Å and the N–H⋯S angle of 106–135°. In the crystals of 1·dtox–4·dtox a combination of the two-component chain motif with the dtox tapes generates 2D layers whereas in 5·dtox a 3D network is formed.