Synthesis and crystal structures of Zn(II) and Cd(II) coordination polymers derived from the flexible N-(4-carboxyphenyl)iminodiacetic acid and auxiliary ligands

Abstract

Abstract Two coordination polymers [Cd3(CPIDA)2(bib)(H2O)2] n 1 and {[Zn6(CPIDA)4(bix)3]·8H2O} n 2 (H3CPIDA = N-(4-carboxyphenyl) iminodiacetic acid, bib = 1,4-bis(N-imidazolyl)butane, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been hydrothermally synthesized and characterized by analytical and IR spectroscopic data. Compound 1 displays an interesting 3D framework with trinodal (4,5)-connected topology, consisting of (4,4) rectangular grid double layers linked by trans-bib ligands. In 2, the corrugated nets with couples of central symmetrical chains constructed by CPIDA3− and bridging trans-bix ligands are pillared by infinite tubes made from CPIDA3− and cis-bix ligands to build a new 3D porous framework with parallelogram-shaped channels, exhibiting a pentanodal (3,4)-connected topology. Moreover, compounds 1 and 2 show intense solid state fluorescence at room temperature.