Hydrothermal Synthesis and Crystal Structure of a New Dimeric Lanthanum (Ⅲ) Complex

A new dimeric lanthanum （Ⅲ） complex [La2（phen）2（C7H3N2O6）6] （phen=1, 10-phenanthroline） was synthesized by the hydrothermal method and determined by single crystal X-ray diffraction analysis. The La（Ⅲ） ion is coordinated to seven oxygen atoms from five carboxylate groups and two nitrogen atoms from a phen ligand, forming a monocapped square antiprismatic geometry. Six carboxylate groups coordinate to two La（Ⅲ） ions in three modes which are chelating bidentate, bridging bidentate and bridging tridentate. The crystal is triclinic with space group P-1, a=1.2030（4） nm, b=1.2962（5） nm, c=1.3330（5） nm, α=104.410（5）°, β=114.048（4）°, γ=100.054 （4）°, V=1.7467 （10） nm3, Mr=952.46, Z=2, Dc=1.811 g·cm-3, F（000）=944, S=1.017, μ=1.320 mm-1, with R1=0.0298 and wR2=0.0625.