Two new Cd and Zn coordination polymers incorporating 1-aminobenzene-3,4,5-tricarboxylic acid: synthesis, crystal structure and characterization.

Aminobenzoic acid derivatives are widely used in the preparation of new coordination polymers since they contain O-atom donors, as well as N-atom donors, and have a rich variety of coordination modes which can lead to polymers with intriguing structures and interesting properties. Two new coordination polymers incorporating 1-aminobenzene-3,4,5-tricarboxylic acid (Habtc), namely, poly[(μ-1-amino-5-carboxybenzene-3,4-dicarboxylato)diaquacadmium(II)], [Cd(CHNO)(HO)], (I), and poly[[bis(μ-1-aminobenzene-3,4,5-tricarboxylato)triaquatrizinc(II)] dihydrate], {[Zn(CHNO)(HO)]·2HO}, (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each tridentate 1-amino-5-carboxybenzene-3,4-dicarboxylate (Habtc) ligand coordinates to three Cd ions to form a two-dimensional network structure, in which all of the Cd ions and Habtc ligands are equivalent, respectively. Polymer (II) also exhibits a two-dimensional network structure, in which three crystallographically independent Zn ions are bridged by two crystallographically independent pentadentate 1-aminobenzene-3,4,5-tricarboxylate (abtc) ligands. This indicates that changing the metal ion can influence the coordination mode of the Habtc-derived ligand and further influence the detailed architecture of the polymer. Moreover, the IR spectra, thermogravimetric analyses and fluorescence properties were investigated.