Coupling between 2-pyridylselenyl chloride and phenylselenocyanate: synthesis, crystal structure and non-covalent interactions

A new pyridine-fused selenodiazolium salt, 3-(phenylselanyl)[1,2,4]selenadiazolo[4,5-a]pyridin-4-ylium chloride dichloromethane 0.352-solvate, C12H9N2Se2+center dot Cl-center dot 0.352CH(2)Cl(2), was obtained from the reaction between 2-pyridylselenenyl chloride and phenylselenocyanate. Single-crystal structural analysis revealed the presence of C-H center dot center dot center dot N, C-H center dot center dot center dot Cl-, C-H center dot center dot center dot Se hydrogen bonds as well as chalcogen-chalcogen (Se center dot center dot center dot Se) and chalcogen-halogen (Se center dot center dot center dot Cl-) interactions. Non-covalent interactions were explored by DFT calculations followed by topological analysis of the electron density distribution (QTAIM analysis). The structure consists of pairs of selenodiazolium moieties arranged in a head-to-tail fashion surrounding disordered dichloromethane molecules. The assemblies are connected by C-H center dot center dot center dot Cl- and C-H center dot center dot center dot N hydrogen bonds, forming layers, which stack along the c-axis direction connected by bifurcated Se center dot center dot center dot Cl-center dot center dot center dot H-C interactions.