Two novel complexes {[Zn（IM4py）2（tp）（H2O）]2H2O}. 1 and {[Cd（IM4py）2（tp）- （H2O）]1.25H2O},, 2 （IM4py = 2-（4＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-l-oxyl and tp = terephthalate dianion） have been synthesized and characterized by elemental analyses, IR spectrum and single-crystal X-ray diffraction. Crystal data for complex I： monoclinic, space group C2/c, a = 20.648（7）, b = 12.130（4）, c = 14.036（4） A, β = 106.351（5）°, C32H42N6O9Zn, Mr = 720.09, V = 3373.3（2） A3, Z= 4, Dc = 1.418 g/cm^3μt（MoKα） = 0.790 mm^-1, F（000） = 1512, the final R = 0.0407 and wR = 0.0894 for 3480 independent reflections with Rint = 0.0432. Crystal data for complex 2： monoclinic, space group C2/c, a = 21.332（6）, b = 12.063（3）, c = 14.246（4） A, β = 106.704（4）°, C32H40.50N6O8.25Cd, Mr = 753.60, V= 3511.2（2） A^3, Z = 4, Dc = 1.426 g/cm^3,μ（MoKα） = 0.679 mm^--1, F（000） = 1554, the final R = 0.0419 and wR = 0.0961 for 3627 independent reflections with Rint = 0.0440. The framework structures of complexes 1 and 2 are 3-D networks via the hydrogen bonds among 1-D chains. The notable characteristics of the two complexes are that the coordination polyhedron of Zn（Ⅱ） adopts a rare distorted five-coordinate square pyramidal geometry in 1, and the Cd（Ⅱ） complex exhibits an unusual distorted seven-coordinate pentagonal bipyramid in 2.
