Synthesis and Characterization of 2,3-Dioximino-1,2,3,4-tetrahydroquinoxaline Complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and UO2(VI)

Abstract

A vic-dioxime, 2,3-dioximino-1,2,3,4-tetrahydroquinoxaline, was prepared as a mixture of dichloroglyoxime and 1,2-phenylendiamine (H₂L). The mononuclear metal complexes have been synthesized with Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) salts. H₂L forms mononuclear complexes [(HL)₂M] with a metal ligand ratio of 1:2 with M= Co(II), Ni(II) and Cu(II). Zn(II), Cd(II) and Hg(II) form with H₂L complexes [(H₂L)MCl₂], which have a metal ligand ratio of 1:1. The results indicated that the metal ions are coordinated through the two N atoms of the ligand, as in most of the vicdioximes. H₂L forms the dinuclear complex [(H₂L)(OH)₂M₂] and a metal ligand ratio of 1:1 with M = UO₂(VI). The composition and the structural formula of the ligand and of the resulted complexes were confirmed by elemental analysis, IR, MS and NMR spectroscopy methods.