Synthesis, crystal structures, and magnetic properties of trinuclear cobalt(II) and nickel(II) complexes with oxamido vanadium(IV)-oxo complex ligand

Abstract By using a macrocyclic vanadium(IV)-oxo complex ligand VOL (H 2 L = 2,3-dioxo-5,6:13,14-dibenzo-7,12-diphenyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as a precursor, two new trinuclear complexes [(VOL) 2 Co(C 2 H 5 OH) 2 ](ClO 4 ) 2 ·2C 2 H 5 OH (1) and [(VOL) 2 Ni(CH 3 OH) 2 ](ClO 4 ) 2 (2) have been synthesized and characterized by elemental analyses, IR spectroscopy, and power and single-crystal X-ray diffraction. In the two complexes, the central ions cobalt(II) and nickel(II) are connected with two VOL fragments via exo - cis oxamido bridge. Magnetic susceptibility measurements indicate that both complexes 1 and 2 show weak ferromagnetic interactions.