Syntheses, structure, and magnetic behavior of two new nickel(II) and cobalt(II) dinuclear complexes with 1,4-dicarboxylatopyridazine. MO calculations of the superexchange pathway through the pyridazine bridge

被引:62
作者
Escuer, A
Vicente, R
Mernari, B
ElGueddi, A
Pierrot, M
机构
[1] UNIV CHOUAIB DOUKKALI,FAC SCI,EL JADIDA,MOROCCO
[2] UNIV AIX MARSEILLE 3,LAB BIOINORGAN STRUCT,URA CNRS 1409,CTR SCI ST JEROME C12,F-13397 MARSEILLE 20,FRANCE
关键词
D O I
10.1021/ic9608859
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Two new dinuclear complexes of formula [M-2(dcpz)(2)(H2O)(4)] in which M is nickel(II) (1) or cobalt(II)(2) and dcpz is the bridging ligand 1,4-dicarboxylatopyridazine have been synthesized and characterized. The crystal structure for the nickel compound has been solved. Complex 1 crystallizes in the orthorombic system, space group Pbca(61), with FW = 521.7, a = 14.501(3) Angstrom, b = 13.169(3) Angstrom, c = 8.774(2) Angstrom, V = 1675(2) Angstrom(3), Z = 4, and R = 0.022. The cobalt compound is isomorphous to 1. The pyridazine ligand acts as a double bridge between the two paramagnetic centers. Magnetic measurements show moderate antiferromagnetic coupling, with J values of -33.6 cm(-1) for 1 and -11.5 cm(-1) for 2. Magnetostructural correlations have been obtained by extended-Huckel MO calculations, and several electronic or structural factors that influence the coupling were analyzed.
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页码:2511 / 2516
页数:6
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