Crystal structure of a mixed-ligand terbium(III) coordination polymer containing oxalate and formate ligands, having a three-dimensional fcu topology

摘要

The title compound, poly[(μ3-formato)(μ4-oxalato)terbium(III)], [Tb(CHO2)(C2O4)]n, is a three-dimensional coordination polymer, and is isotypic with the LaIII, CeIII and SmIII analogues. The asymmetric unit contains one TbIII ion, one formate anion (CHO2?) and half of an oxalate anion (C2O42?), the latter being completed by application of inversion symmetry. The TbIII ion is nine-coordinated in a distorted tricapped trigonal–prismatic manner by two chelating carboxyl-ate groups from two C2O42? ligands, two carboxyl-ate oxygen atoms from another two C2O42? ligands and three oxygen atoms from three CHO2? ligands, with the Tb—O bond lengths and the O—Tb—O bond angles ranging from 2.4165?(19) to 2.478?(3)?? and 64.53?(6) to 144.49?(4)°, respectively. The CHO2? and C2O42? anions adopt μ3-bridging and μ4-chelating-bridging coordination modes, respectively, linking adjacent TbIII ions into a three-dimensional 12-connected fcu topology with point symbol (324.436.56). The title compound exhibits thermal stability up to 623?K, and also displays strong green photoluminescence in the solid state at room temperature.