Poly[[aquatris(μ4-benzene-1,2-dicarboxylato)dilanthanum(III)] hemihydrate]

Abstract

The asymmetric unit of the title coordination polymer, {[La2(C8H4O4)3(H2O)]·0.5H2O}n, contains two independent LaIII atoms, one of which is surrounded by eight carboxylate-O atoms from six benzene-1,2-dicarboxylate (BDC) anions in a bicapped trigonal–prismatic geometry. The other LaIII atom is nine-coordinated in a tricapped trigonal–prismatic geometry, formed by eight carboxylate-O atoms from six BDC anions and a coordinated water molecule. The BDC anions bridge the LaIII atoms, forming a two-dimensional polymeric complex parallel to (001). The crystal structure contains weak O—H...O and non-classical C—H...O hydrogen bonds. A C—H...π interaction is also present in the crystal structure. The uncoordinated water molecule shows half-occupation.