Unusual Substitution in Hydrazinobenzoic Acid upon Complexation. Crystal and Molecular Structure of Hydrazinobenzoic Acid Hydrochloride

Abstract The crystal and molecular structure of 2-hydrazinobenzoic acid was determined. In solution in the presence of copper(II) chloride, 2-hydrazinobenzoic acid is transformed into 2-chlorobenzoic acid (HL 1 ) and is coordinated to copper(II) cations to form the binuclear structure [Cu(H 2 O)] 2 (µ-L 1 ) 4 with bridging carboxylate groups of the ligand (L 1 ) – . Three complexes of HL 1 with Fe(II), Co(II), and Zn(II) were isolated in the crystalline state and studied by spectroscopic methods. It was found that the organic molecules are involved in the complexes in the monodeprotonated chelating form.