Structure and luminescence of a 2-dimensional 2,3-pyridinedicarboxylate coordination polymer constructed from lanthanide(III) dimers

A new two-dimensional lanthanide coordination polymer, [Ln(C7H3NO4)(C7H4NO4)(H2O)]n (Ln = trivalent Pr, Nd, Sm, Eu, and Tb) has been hydrothermally synthesized from reaction with 2,3-pyridinedicarboxylic acid. The compound crystallizes in the P21/c space group and is built from sheets composed of carboxylate-bridged Ln dimers stacked along the [1 0 0] direction and held together by hydrogen bonding between carboxylic acid groups. The organic component is successful at sensitizing lanthanide emission in the Sm, Eu, and Tb compounds with quantum yields experimentally determined of 0.60, 4.6, and 2.6%, respectively.