CRYSTAL-STRUCTURE, MAGNETIC-PROPERTIES AND ORBITAL INTERACTIONS OF THE BINUCLEAR FUMARATO-BRIDGED DIETHYLAMINO)ETHYL)-SALICYLIDENAMINATO)COPPER(II)] COMPLEX

The title compound of formula [CU2(SalNEt2)2(CH2O4)], where NEt2=N-(2- (diethylamino)ethyl)-salicylidenaminate, has been synthesized and its structure solved at room temperature. It crystallizes in the monoclini c system, space group P2(1)/c, with a = 10.463(2), b = 16.048(2), c = 9.434(l) angstrom, beta = 106.91(l)-degrees and Z = 2. In the molecula r structure of this centrosymmetric compound the two equivalent copper (II) ions are bridged by the fumarato ligand coordinated in an amphimo nodentate mode. The local geometry around both copper(II) ions is appr oximately square planar. Magnetic susceptibility data for the complex as a function of temperature show weak exchange interactions. The fitt ing of these data to the HDVV (H = -2JS1S2), s1 = s2 = 1/2 spin exchan ge model, yields a 2J value of - 1.8 cm-1. An orbital interpretation o f the observed weak antiferromagnetic interactions is presented based on the results of extended Huckel calculations on a model compound.