SYNTHESES AND MAGNETISM OF LINEAR TRINUCLEAR COPPER(II) COMPLEXES WITH STRONG ANTIFERROMAGNETIC INTERACTION

Four novel trinucleat copper(II) complexes were synthesized, namely {[Cu(pba)] [Cu(L)](2)}(ClO4)(2), where pba denotes 1,3-propylenebis(oxamato) and L is 2,2'-bipyridyl (bpy), 4,4'-dimethyl-2,2'-bipyridyl (Me(2)bpy), 1,10-phenanthroline(phen) or 5-nitro-1,10-phenanthroline (NO2-phen). Based on IR, elemantry analyses, conductivity measurements and electronic spectra, these complexes were proposed to have oxamido-bridged structures and to consist of three copper(II) ions in which each copper(II) ion has a square planar envionment. The temperature dependence of the magnetic susceptibility of {[Cu(pba)][Cu (NO2-phen)](2)}(ClO4)(2) has been studied in the range from 4.1 to 300 K, giving the exchange interval J=-124 cm(-1). The result reveals the operation of a strong antiferromagnetic spin-exchange interaction between the adjacent copper ions.