Structures and photoluminescence of coordination polymers assembled from bifunctional ligand containing both tetrazole and imidazole groups

Abstract

Three new coordination polymers, namely, {[Cu2(IPT)(SO4)(OH)(H2O)]·H2O}n (HIPT=5-(4-(1H-imidazol-1-yl)phenyl)- 1H-tetrazolate, 1), {[Cd2(IPT)(NPA)(OH)]·H2O}n (H2NPA=5-nitroisophthalic acid, 2), and {[Zn2(IPT)(IDC)(H2O)]·3H2O}n (H3IDC=1H-imidazole-4,5-dicarboxylic acid, 3), were assembled from a bifunctional organic ligand containing both tetrazole and imidazole groups with/without the aid of carboxylate coligands. Compound 1 possesses 2D structure built by 1D [Cu2(IPT)(SO4)(OH)]n secondary building blocks and IPT− linkers. The 2D networks are linked into 3D supramolecular framework via water chains in helical conformation. Compound 2 displays 3D pillar-layer framework with 2D layers based on tetranuclear Cd(II) SBUs and NPA2− pillars. Compound 3 exhibits a 3D framework constructed from the interconnection of 1D [Zn-IDC]n chains and binuclear Zn2(IPT)2 rings. The thermal stabilities of porous compound 3 and luminescent properties of compounds 2 and 3 have also been studied in detail. They exhibit intense solid-state fluorescent emissions at room temperature.