Syntheses, crystal structures, and fluorescent properties of 2-D Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and 1,2,4,5-benzenetetracarboxylate ligands

Crystal structure of catena-poly[aqua[(μ2-4,5-dicarboxylato-2-(2-carboxylatophenyl)imidazol-1-ido-κ4 N,O,O′:N′)](μ2-4,4′-bipyridine-κ2 N:N′)dicopper(II)], C22H14Cu2N4O7

C22H14Cu2N4O7, monoclinic, P21/n (no. 14), a = 7.7885(4) Å, b = 14.9974(8) Å, c = 17.7464(10) Å, β = 102.184(2)°, V = 2026.22(19) Å3, Z = 4, R gt(F) = 0.0357, wR ref(F 2) = 0.0936, T = 300(2) K.

Two new CdII and ZnII 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 (H₃abtc), namely, poly[(μ₃-1-amino-5-carboxybenzene-3,4-dicarboxylato)diaquacadmium(II)], [Cd(C₉H₅NO₆)(H₂O)₂]_n, (I), and poly[[bis(μ₅-1-aminobenzene-3,4,5-tricarboxylato)triaquatrizinc(II)] dihydrate], {[Zn₃(C₉H₄NO₆)₂(H₂O)₃]·2H₂O}_n, (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^2-) ligand coordinates to three Cd^II ions to form a two-dimensional network structure, in which all of the Cd^II ions and Habtc^2- 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^3-) ligands. This indicates that changing the metal ion can influence the coordination mode of the H₃abtc-derived ligand and further influence the detailed architecture of the polymer. Moreover, the IR spectra, thermogravimetric analyses and fluorescence properties were investigated.

Luminescent Functionalised Supramolecular Coordination Polymers Based on an Aromatic Carboxylic Acid Ligand for Sensing Hg2+ Ions

Two luminescent functionalised supramolecular coordination polymers, namely, [Zn(TPDC-2CH3)(H2O)2]·H2O (1) and [Cd(TPDC-2CH3)(H2O)4]·H2O (2), were successfully synthesised by the reaction of 2′,5′-dimethyl-[1,1′:4′,1″-terphenyl]-4,4″-dicarboxylic acid (H2TPDC-2CH3) with Zn2+ and Cd2+ ions, respectively. X-Ray crystallographic analysis reveals that both compounds 1 and 2 exhibit fascinating 3D supramolecular networks, in which metal ions are linked by ligands to form a 1D chain which further extends to a 3D structure through the interaction of hydrogen bonding. The use of 1 and 2 as luminescent sensors for the optical detection of metal ions: Na+, K+, Hg2+, Ag+, Ca2+, Co2+, Ni2+, Mn2+, Cu2+, Zn2+, Cd2+, Pb2+, Mg2+, Al3+, Fe3+, Fe2+, In3+, Bi3+, and Cr3+ was carried out in aqueous solution, and the results indicated that compound 1 could effectively detect Hg2+ ions among various cations at room temperature, with a detection limit of 3.6 × 10−15 M.