Synthesis, characterization and X-ray crystal structures of trinuclear zinc (II) and cadmium(II) complexes derived from an oxovanadium(IV) complex ligand

摘要

By using a macrocyclic oxovanadium(IV) complex ligand VOL (H2L = 2,3-dioxo-5,6: 13,14-dibenzo-7,12-diphenyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as precursor, two new trinuclear complexes [(VOL)(2)Zn(CH3OH)(2)](ClO4)(2)center dot 5CH(3)OH (1) and [(VOL)(2)Cd(CH3OH)(2)](ClO4)(2)center dot 3CH(3)OH center dot 1.82H(2)O (2) have been synthesized. Their structures were determined by single-crystal X-ray diffraction and further characterized by elemental analyses, FT-IR, UV-Vis spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). In the two complexes, the central zinc(II) and cadmium(II) ions are connected with two VOL fragments via exo-cis oxamido bridge. Magnetic susceptibility studies (2-300 K) of complex 1 indicate the occurrence of weak antiferromagnetic coupling between the paramagnetic metals. The experimental data have been fitted according to Heisenberg Hamiltonian (H) over cap = 2J (S) over cap (1)(S) over cap (2), leading to J = -0.31 cm(-1), g = 2.01. (C) 2016 Elsevier B.V. All rights reserved.