Synthesis, Characterization and Crystal Structure of a Novel Complex of Maleic Acid with Gadolinium(III)

Abstract

A novel ionic complex of gadolinium(III) with maleic acid, [Gd(C₄H₃O₄)₂(H₂O)₇](C₄H₃O₄).H₂O, was synthesized and characterized by elemental analysis, molar conductance, TG, DTA and IR. The structure of the complex was determined by single-crystal X-ray diffraction methods and refined to R = 0.024, R _w = 0.029 for 4906 reflections with I ≥ 3[sgrave] (I). Crystals are triclinic with a= 10.317(2), b=16.627(3), c = 7.192(3)A, α = 91.99(2), β= 109.18(2), γ = 72.00(2)[ddot], μ(MoK_x) = 31.047cm⁻¹, and Z = 2. The space group is P _r The gadolinium ion is coordinated by two bimaleates and seven waters forming a positive complex, and another bimaleate anion compensates for charge. The metal coordination number is nine and the coordination polyhedron is a distorted, monocapped square antiprism.

Key Words:

• GadoIinium(III)
• maleic acid
• synthesis
• crystal structure