Synthesis and structure of bis{(mu-benzoato-O,O,O ')(mu-benzoato-O,O ')(nitrato-O,O ')(2,2 '-dipyridyl)neodymium(III)}

dThe complex [Nd-2(mu -C6H5CO2)(4)(NO3)(2)(Dipy)(2)] was synthesized and ch aracterized by IR spectroscopy and X-ray crystallography. Crystals are tric linic: a = 10.245(2) Angstrom, b = 11.005(2) Angstrom, c = 11.0421(2) Angst rom, alpha = 81.91(3)degrees, beta = 76.60(3)degrees, gamma = 70.87(3)degre es, space group P (1) over bar. In the centrosymmetric dimeric molecule, th e Nd-Nd' distance is 3.988 Angstrom, and the coordination number of neodymi um is 9. The dimer is formed by two bidentate benzoate bridges (Nd-O(1), 2. 408(2) Angstrom; Nd-O(2)', 2.404(2) Angstrom) and two tridentate chelating benzoate bridges (Nd-O(3), 2.463(2) Angstrom; Nd-O(4), 2.693(2) Angstrom; N d-O(4)', 2.411(2) Angstrom). The coordination of neodymium is completed by the bidentate chelating nitrate ion (Nd-O(5), 2.526(2) Angstrom; Nd-O(6), 2 .577(2) Angstrom) and the 2,2'-dipyridyl molecule (Nd-N(1), 2.626(2) Angstr om; Nd-N(2), 2.648(2) Angstrom). The coordination polyhedron of neodymium i s a distorted monocapped square antiprism. The aromatic rings of the coordi nated ligands are involved in pi-pi interaction.