Synthesis of lanthanide coordination polymers with benzophenone-4,4′-dicarboxylate:: Effect of lanthanide contraction on structures

Four lanthanide coordination polymers with benzophenone-4,4'-dicarboxylic acid (H(2)bpndc) and 1,10-phenanthroline (phen), [Ln(2)(bpndc)(3)(phen)] (Ln=La (1), Pr (2) and Th (3)), [Yb(bpndc)(1.5)(phen)](.)0.5H(2)O (4) were obtained through solvothermal synthesis. The crystallographic data show that 1, 2, and 3 are isostructural, the Ln(III) ions in 1, 2 and 3 are all eight- and ten-coordinated, respectively, and thus the Ln(III) ions are connected by bpndc ligands, resulting in an interpenetrating 3D structure. While in 4, the Yb(III) ions are eight-coordinated and connected by bpndc ligands into a 3D structure with 1D rhombic channels, which result from the effect of lanthanide contraction from La(III) to Yb(III) ions, and the bpndc ligands in 1, 2, 3, and 4 display three types of coordination modes.