SYNTHESIS, SPECTRA AND CRYSTAL-STRUCTURE OF S(1,10-PHENANTHROLINE)DI(MU-ALPHA-AMETHYLACRYLATO) LANTHANIDE(III)DIMERS

The homodinuclear complexes, [RE(CH2C(CH3)COO)(3)(phen)](2), (RE=La, C e, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, phen=1,10-phenant hroline), have been synthesized and characterized by elemental analysi s, molar conductance, IR and NMR. The complex [La(CH2C(CH3)COO)(3)(phe n)(HL)](2) (HL)=CH2C(CH3)COOH) crystallizes in the monoclinic space gr oup P2(1)/c with Z = 2. Cell dimensions are a = 9.878(2), b = 11.071(1 ), c = 26.528(3) Angstrom, beta = 94.02(1)degrees and the structure wa s refined to R = 0.036 for 4136 observed reflections. The structure co nsists of a centrosymmetric dinuclear molecule. Lanthanum(III) atoms a re bridged by two bidentate and two terdentate carboxylato groups with an La...La separation of 4.0456(4) Angstrom. Each lanthanum(III) atom is nine-coordinated and exhibits a slightly distorted, tricapped, tri gonal prism. The La-O and La-N bond distances are in the range 2.473-2 .738 and 2.696-2.722 Angstrom, respectively.