Four lanthanide coordination polymers were constructed from mixed ligands of phenanthroline derivative and flexible polydentate ligands, [Gd₂ (1,3-BDC)3(MOPIP) ₂]_n•nH₂O (1), [Gd(1,4-BDC)1.5(MOPIP)] _n• (2), [Yb(1,4-BDC)1.5(MOPIP)] _n• (3) and [Sm(1,4-BDC)1.5(MOPIP)] _n• (4), (MOPIP = 2-(4-methoxyphenyl)-1Himidazo[ 4,5-f ][1,10]phenanthroline, 1,3-BDC = benzene-1,3- dicarboxylic acid, 1,4-BDC = benzene-1, 4-dicarboxylic acid). The polymers have been synthesized under hydrothermal conditions and structurally characterized by single crystal X-ray diffraction analysis. Compound 1 possesses one-dimensional chain structure,and expands into the three-dimensional supramolecular architecture by π • • • π stacking and hydrogen-bonding interactions. Meanwhile, compounds 2–4 exhibit three-dimensional frameworks with pcu topology (4¹²•6³). The structural differences among such compounds show that the steric hindrances of benzene dicarboxylicacid ligands play a key role in the assembly and the structures of the title compounds. Compounds 1 and 2 act as efficient Lewis acid catalysts for the cyanosilylation of benzaldehyde in high yields, due to the strong Lewisacidity