1,10-Phenanthroline-copper mediated ligand transformations: Synthesis and characterization of unusual mixed ligand complexes of copper (II)

Abstract

Abstract The present work describes the results of treatment of two pentacoordinated copper(II) complexes with 1,10-Phenanthroline (PHEN). During the course of the reaction, in situ generated PHEN-Cu complex has mediated the ligand transformations. In spite of the structural similarities of the precursor complexes used, structurally distinct unusual mixed ligand complexes viz. dichlorido (3-methyl [1,2,4] triazolo[3,4-b] [1,3] benzothiazole) 1,10-phenanthroline copper(II) and dichlorido-µ-N,N-benzimidazolato dibenzimidazole di-1,10-phenanthroline dicopper (II) chloride are formed. These complexes are characterized by IR, ESI-MS, EPR and UV–Vis spectral studies. X-ray crystal structures of both the complexes are described. Further, the observed results have inspired the synthesis of 3-methyl [1,2,4] triazolo[3,4-b] [1,3] benzothiazole, by a new synthetic approach.