In situ synthesis of a series of lanthanide coordination polymers based on N-heterocyclic carboxylate ligands: Crystal structure and luminescence

A series of novel lanthanide coordination polymers (Ln-CPs) have been constructed by 2-(pyridin-2-yl-N-oxide)-1H-imidazole-4,5-dicarboxylate (H3POIDC) ligand, which derived from the partial oxidation of 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylate (H3PIDC) in situ reaction. Compounds 1–3 with the infinite left- and right-hand helices show 3D supramolecular structure constructing from 1D chains connecting each other through strong hydrogen-bond interactions. Compounds 4–7 show 2D layered structure with sql topology which are built from 4-connected nodes. Moreover, compounds 1–6 show strong luminescence emission in solid state, especially compound 1 exhibits obvious luminescence quenching for Hg2+ ion.