f The challenge on lanthanide-transition-metal (Ln-M) coordination polymer crystals and a corresponding ligand-directed assembly strategy of crystal engineering were studied. The multi functional 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, Ce-2(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 x 0.2 x 0.2 mm(3), 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. (C) 2008 Elsevier B.V. All rights reserved.