SYNTHESIS AND STRUCTURE OF DINUCLEAR COMPLEXES OF TERBIUM(III) WITH 4-ACETYLBISPYRAZOLONE

Two novel dinuclear complexes of terbium(III) with henyl-3'-methyl-5'- pyrazolone-4')-1,5-pentanedione (H(2)L), Tb(2)L(3).6H(2)), Tb(2)L(3).5 DMF, have been synthesized. The crystal structure of Tb(2)L(3).5DMF wa s determined by X-ray diffraction methods. Crystals are triclinic, spa ce group P ($) over bar 1 with a = 16.957(5), b = 17.877(7), c = 18.26 9(2)Angstrom, alpha = 110.35(2), beta = 101.29(2), gamma = 111.00(2)de grees, V = 4511(6)Angstrom(3), Mr = 2010.76, Z = 2, Dx = 1.48 g cm(-3) , mu = 16.45 cm(-1), F(000) = 2,052, R = 0.058 with 6574 reflections u sed in refinement. In the complex, L acts as a bridging ligand and bon ds two terbium atoms with its two P-diketone groups. Each terbium ion bonds to two DMF solvent molecules. The coordination number of the two terbium ions is eight. The eight oxygen atoms around the terbium make a distorted square antiprismatic coordination polyhedron.