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, C 12 H 9 N 2 Se 2 + ·Cl − ·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...N, C—H...Cl − , C—H...Se hydrogen bonds as well as chalcogen–chalcogen (Se...Se) and chalcogen–halogen (Se...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...Cl − and C—H...N hydrogen bonds, forming layers, which stack along the c -axis direction connected by bifurcated Se...Cl − ...H—C interactions.