The in situ formation of a Cu(II) mesoionic complex via unexpected ring closure and investigation of its magnetic properties

Abstract

The reaction of diphenylthiocarbazone, picolinic acid (HL1) with Cu(OAc)2·H2O under base condition yields a mesoionic complex [Cu(II)(L1)2(L2)]·MeOH, where L2, mesoionic ligand 2,3-diphenyltetrazole-5-thione ligand, derived from an unusual cyclization of diphenylthiocarbazone. Crystallographic studies show that the mesoionic ligand L2 is weakly interacted with a planar Cu(II) complex via S…Cu electrostatic force while S donor atom sits on the top of a pyramidal geometry of five-coordinated Cu complex. π-contacts between two adjacent mesoionic ligands L2 in the crystal are also observed. The complex is characterized by IR, UV/vis, Powder XRD, and SQuID magnetometry studies on magnetic property of the powder sample are also discussed.