Crystal structure and luminescence of a europium coordination polymer {[Eu(p-MOBA)3•2H2O]-0.5H2O•0.5(4,4′-bipy)}∞

The structure of the complex [Eu ( p-MOBA)(3) - 2H(2)O]. 0.5H(2)O.0.5(4,4'-bipy)}(x) (p-MOBA: p-methoxybenzoate, 4,4'-bipy: 4,4'-bipyridine) was determined by single crystal X-ray diffraction study. Each europium atom is coordinated with two oxygen atoms of the chelated carboxyl group, four oxygen atoms of the four bidentate bridging carboxylate groups and two oxygen atoms of two water mole-cules, forming an infinite polymeric chain structure. Excitation and luminescence spectra were observed at 77 K. The high resolution spectrum of the complex shows that the europium ion site in the crystal has low symmetry. The complex displays intense luminescence which may be related to the p-MOBA ligand and the polymeric coordination.