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 (H 3 abtc), namely, poly[( 3 -1-amino-5-carboxybenzene-3,4-dicarboxylato)diaquacadmium(II)], [Cd(C 9 H 5 NO 6 )(H 2 O) 2 ] n , (I), and poly[[bis( 5 -1-aminobenzene-3,4,5-tricarboxylato)triaquatrizinc(II)] dihydrate], {[Zn 3 (C 9 H 4 NO 6 ) 2 (H 2 O) 3 ]Á-2H 2 O} n , (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each tridentate 1-amino-5-carboxybenzene-3,4dicarboxylate (Habtc 2À ) ligand coordinates to three Cd II ions to form a twodimensional network structure, in which all of the Cd II ions and Habtc 2À ligands are equivalent, respectively. Polymer (II) also exhibits a two-dimensional network structure, in which three crystallographically independent Zn II ions are bridged by two crystallographically independent pentadentate 1-aminobenzene-3,4,5-tricarboxylate (abtc 3À ) ligands. This indicates that changing the metal ion can influence the coordination mode of the H 3 abtc-derived ligand and further influence the detailed architecture of the polymer. Moreover, the IR spectra, thermogravimetric analyses and fluorescence properties were investigated. Shao et al. Two new Cd II and Zn II coordination polymers 1071 Figure 7Fluorescence excitation and emission spectra of uncoordinated H 3 abtc and polymers (I) and (II) in the solid state.

Changing the pH value of a reaction system can result in polymers with very different compositions and architectures. Two new coordination polymers based on 1,1 0 -[1,4-phenylenebis(methylene)]bis (3,5- [Cd(C 22 H 14 N 2 O 8 )] n , (II), have been prepared in the presence of NaOH or HNO 3 and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each Cd II ion is coordinated by two halves of independent L 2À ligands, forming a one-dimensional chain structure. In the crystal, these chains are further connected through O-HÁ Á ÁO hydrogen bonds, leading to a three-dimensional hydrogen-bonded network. In polymer (II), each hexadentate L 2À ligand coordinates to six Cd II ions, resulting in a three-dimensional network structure, in which all of the Cd II ions and L 2À ligands are equivalent, respectively. The IR spectra, thermogravimetric analyses and fluorescence properties of both reported compounds were investigated.