Novel lanthanide–transition-metal coordination polymer materials: Crystal engineering challenges and a ligand-directed assembly strategy

Abstract: The challenge on lanthanide–transition-metal (Ln–M) coordination polymer crystals and a corresponding ligand-directed assembly strategy of crystal engineering were studied. The multifunctional isonicotinate with mixed donor sites was selected as the directing ligand to link lanthanide and transition-metal ions on the basis of the coordination nature of both different types of metal ions. A new three-dimensional (3D) Ln–M heterometallic coordination polymer crystal, Ce2(H2O)2(OAc)Cu4Cl3(IN)6 (1) (HIN=isonicotinic acid, HOAc=acetic acid), has been grown under hydrothermal crystal growth conditions and characterized by IR, UV–vis, photoluminescent spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. The crystal with sizes 0.8×0.2×0.2mm3, crystallizing in monoclinic C2/c space group, structurally exhibits a 3D coordination framework based on the linkage of 1D Ce−carboxylate chains and {Cu4Cl3} complexes with different geometries by IN ligands. The results show that current strategy can be used to design and grow novel heterometallic coordination polymer crystals. [Copyright &y& Elsevier]