STRUCTURE AND MAGNETISM OF TETRA ACETATO BRIDGED BINUCLEAR ND-III COMPLEX

A binuclear Nd-III complex of formula [Nd-2(phen)(2)(ONO2)(2)(CH3COO)( 4)] (phen = phenanthroline) has been prepared and its structure and ma gnetism have been studied by X-ray diffraction and magnetic susceptibi lity measurements. The structure consists of two Nd-III ions bridged b y four-bidentate CH3COO- groups and coordinated by two phen and two ON O,groups to give a binuclear [Nd-2(phen)(2)(ONO2)(2) (CH3COO)(4)] unit . This molecule possesses C-2 point group symmetry and the Nd atom is 9-coordinated in an irregular polyhedron. The average Nd-N distance (2 .649 Angstrom) is longer than the average Nd-O(2.493 Angstrom). All fo ur CH3COO- groups are bidentate ligands which connect to Nd as bridges while the O(4) atom is the mu(3) bridge oxygen and links two Nd atoms . The Nd-Nd distance is relatively short (3.974 Angstrom). Cryomagneti c investigations (4.5-300 K) reveal a weak antiferromagnetic coupling with J = -0.16 cm(-1). (C) 1997 Elsevier Science Ltd.