Novel Lanthanide (III) Complexes Derived from an Imidazole-Biphenyl-Carboxylate Ligand: Synthesis, Structure and Luminescence Properties.

A series of neutral mononuclear lanthanide complexes (Ln = La, Ce, Nd, Eu, Gd, Dy, Ho) with rigid bidentate ligand, HL (4'-(1-imidazol-1-yl)biphenyl-4-carboxylic acid) were synthesized under solvothermal conditions. The coordination compounds have been characterized by infrared spectroscopy, thermogravimetry, powder X-ray diffraction and elemental analysis. According to X-ray diffraction, all the complexes are a series of isostructural compounds crystallized in the monoclinic space group. Additionally, solid-state luminescence measurements of all complexes show that complex displays the characteristic emission peaks of Eu(III) ion at 593, 597, 615, and 651 nm.