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.