[N,N’-diethyl-4,4′-bipyridinium][CdX4] (X = Cl or Br) with N,N’-diethyl-4,4′-bipyridinium generated in situ: An Effective Route to Viologen Compounds

Abstract

Two viologen (4,4‘-bipyridinium) compounds, [MQ2+][CdX4] (X = Cl or Br; MQ2+=N,N’-diethyl-4,4′-bipyridinium) with the MQ2+ generated in situ, have been synthesised via solvothermal reactions and structurally characterised by single-crystal X-ray diffraction. The MQ2+ moieties and [CdX4]2– anions are interconnected by hydrogen bonding to form a supramolecular framework. Both compounds exhibit broad and strong emission in the yellow region which, following theoretical investigation, is ascribed to ligand-to-ligand charge transfer.