Synthesis and Characterization of New Symmetrical Binucleating Ligands and Their &mgr;-Phenoxo-Bridged Bicopper(II) Complexes: Structural, Electrochemical, and Magnetic Studies.
The new pentadentate binucleating ligands 2,6-Bis[N-(3,5-dimethyl-2-hydroxybenzyl)-N-methylaminomethyl]-4-chlorophenol, H(3)L(1), and 2,6-bis[N-(3,5-dichloro-2-hydroxybenzyl)-N-cyclohexylaminomethyl]-4-methylphenol, H(3)L(2), and their binuclear copper(II) complexes of the general formulas [Cu(2)L(1)(X)] (X = OMe, OH, Br (1-3)) and [Cu(2)L(2)(X)] (X = OMe, OH, Br (4-6)) have been prepared. The molecular structure of the complex [Cu(2)L(1)(OMe)].MeOH was studied by X-ray crystallography. It exists as a discrete binuclear species in which the copper atoms are in a distorted square planar environment with two oxygen bridges provided by the phenolate of the ligand and methoxy exogenous donor and the Cu.Cu distance is 3.030 Å. A cyclic voltammetric study of the complexes shows two quasireversible reduction waves at negative potentials. A cryomagnetic investigation on powdered samples of the complexes (1-6) shows moderately strong antiferromagnetic coupling (-2J in the range 120-300 cm(-)(1)). A comparison of the electrochemical and magnetic properties of the complexes prepared from both ligands is discussed. Crystal data for the complex [Cu(2)L(1)(OMe)].MeOH: molecular formula C(30)H(39)ClCu(2)N(2)O(5), monoclinic, space group P2(1)/c with a = 13.222(1) Å, b = 15.912(1) Å, c = 14.149(1) Å, beta = 91.64(1) degrees, and Z = 4.
Amudha
P.
P
Department of Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai-25, India.
Kandaswamy
M.
M
Govindasamy
L.
L
Velmurugan
D.
D