Synthesis and Uncommon Structural Characterization of Novel Zinc and Cadmium Complexes with Imino Nitroxide Radical

摘要

Two novel complexes {[Zn(IM4py)2(tp)(H2O)]·2H2O}n 1 and {[Cd(IM4py)2(tp)- (H2O)]·1.25H2O}n 2 (IM4py=2-(4'-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-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 1: 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) (A)3, Z=4, Dc=1.418 g/cm3, μ(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/cm3, 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.