Syntheses of Zn or Cd complexes from dicarboxylate ligand exhibiting an axial chirality and auxiliary ligand

摘要

Coordination complexes [Cd(bpy-3,3'-dc)(bibp)(H2O)(3)](n) (1), [Zn(bpy-3,3'-dc)(bibp)(H2O)(2.5)](n) (2), [Cd-2(bpy-3,3'-dc)(ptd)(2)(H2O)(6)](ClO4)(2)(H2O)(5) (3) and [Zn-2(bpy-3,3'-dc)(ptd)(2)(H2O)(6)](ClO4)(2)(H2O)(6)(CH3CN) (4) have been synthesized by the reaction of 2,2'-bipyridine-3,3'-dicarboxylic acid (H(2)bpy-3,3'-dc) and bipb or ptd with the Zn(II) or Cd(II) salts using different methods, where the bipb and ptd are 2,2'-bis(imidazol-1-ylmethyl)-biphenyl and 1,10-Phenanthroline-5,6-dione, respectively. Compound 1 featured a 1D chain, in which the metal centers bridged by bpy-3,3'-dc was chiral. Two chiral chains linked by bibp ligands were formed in a centro-symmetric fashion. Complex 2 was a two-dimensional network arising from two kinds of 2(1) helical chains. Being linked by a bpy-3,3'-dc ligand, the two metal centers in 3 and 4 exhibited the same absolute configuration. These binuclear units acted as chiral origins and were interconnected by directional hydrogen-bond interactions to form a 3D homochiral network. Significant CD signals exhibited that chiral solids were crystallized through the spontaneous resolution. (C) 2014 Elsevier B.V. All rights reserved.