ZnCl3(4-methyl-4,4′-bipyridinium) with 4-methyl-4,4′-bipyridinium generated in situ: synthesis, structure and photoluminescence

A novel viologen(4,4′-bipyridinium)-based complex ZnCl3(4-methyl-4,4′-bipyridinium) (1), in which the 4-methyl-4,4′-bipyridinium (MQ+) was generated in situ, has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. The title complex features an isolated structure, based on the MQ+ ligand coordinating to a zinc atom that is further terminally bound by three chlorine atoms. Photoluminescence investigation reveals a strong emission in blue region, which may originate from π → π∗ charge-transfer interaction of the MQ+ ligand.