A new calcium trimellitate coordination polymer with a chain-like structure

The calcium trimellitate, Ca(H2O)[(O2C)(2)-C6H3-CO2H], was hydrothermally synthesized from a mixture of calcium hydroxide, 1,2,4-benzenetricarboxylic (or trimellitic) acid and water at 180 degrees C for 24 h (under autogenous pressure). Its crystal structure has been determined by single-crystal X-ray diffraction analysis using synchrotron radiation (station 9.8, SRS Daresbury, UK). It consists of infinite chains of calcium bicapped trigonal prismatic polyhedra connected to each other through the 1,2,4-benzenetricarboxylate ligand. The eight-fold coordinated calcium cation is bonded to one terminal water molecule, two carboxylate groups with a chelating conformation and three carboxylate groups in a monodentating mode. One of the monodentate carboxylate is terminal with the occurrence of protonated C-OH bonding. Triclinic space group P-1 with a = 6.9073(4) angstrom, b = 6.9917(4) angstrom, c = 10.3561(6) angstrom, alpha = 87.178(1)degrees, beta = 83.233(1)degrees, gamma = 69.576(1)degrees, V = 465.41(5) angstrom(3). (C) 2007 Elsevier Masson SAS. All rights reserved.