Synthesis and crystal structure of two new rare earth trimesate complexes:ErTMA(H2O)(5)center dot 3.5H(2)O and YTMA(H2O)(6)

Two lanthanide complexes with trimesic acid have been obtained and structur ally characterised. Er[C6H3(COO)(3)](H2O)(5). 3.5H(2)O crystallises in the monoclinic space group C2/c with unit cell dimensions of: a = 14.7396(15), b = 16.9874(15), c = 14.4591(14) Angstrom, beta = 118.754(9)degrees and Z = 8. Y[C6H3(COO)(3)](H2O)(6) crystallises in the monoclinic space group Cc w ith unit cell dimensions of: a = 11.373(2), b = 17.850(3), c = 7.134(1) Ang strom, beta = 119.14(3)degrees and Z = 4. Both structures consist of an ext ended network of metal ions coordinated by trimesate ions. The observations are analysed in terms of steric crowding about lanthanide atom using a con e-packing model. (C) 1999 Elsevier Science S.A. All rights reserved.