First example of lanthanide coordination polymer of 2,5-pyrazinedicarboxylate

A lanthanum coordination polymer, [La(2,5-PZDC)(1.5)(H2O)](n), (2,5-PZDC = 2,5-pyrazinedicarboxylate) has been synthesized by using the reaction of LaCl3 center dot 7H(2)O with 2,5-pyrazinedicarboxylic acid under hydrothermal condition and structurally characterized by X-ray diffraction method. It crystallizes in the triclinic system P (1) over bar with a = 6.297(2) angstrom, b = 6.762(2) angstrom, c = 13.450(4) angstrom, alpha = 82.984(5)degrees, beta = 83.164(5)degrees, gamma = 63.260(4)degrees, V = 506.3(3) angstrom(3), Z = 2. The La3+ ion is nine-coordinate in a N2O7 environment, with a tricapped trigonal prism geometry, and the ligand 2,5-pyrazinedicarboxylate adopts two coordination modes, through which lanthanum ions are linked together to form a three-dimensional structure.