Cadmium Coordination Polymers Constructed from in Situ Generated Amino-Tetrazole Ligand: Effect of the Conditions on the Structures and Topologies

Five Cd(II) coordination polymers with the in situ generated ligand 5-amino-tetrazolate (atz(-)) were prepared from the hydrothermal reactions of the corresponding Cd(II) salts, and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA) and single crystal X-ray diffraction. The results of X-ray crystallographic analysis revealed that compounds {[Cd-5(atz)(9)]Cl}(n)center dot 2nH(2)O (1) and {[Cd-5(atz)(9)](SO4)(0.5)}(n)center dot 2nH(2)O (3) are isostructural with the perfect Kagome layers bridged by [Cd-2(U-4-atz)(3)] clusters to generate a three-dimensional (3D) rare Ion (topological type symbol) topological network with a vertex symbol of 6(6). Its hexagonal channels are Filled by Cl- or SO42- anions and water molecules. Compound [Cd-5(atz)(8)(mu(2)-Cl)(2)](n)center dot 3nH(2)O (2) contains three different kinds of bridging modes of the atz(-) anion and is ail intricate 3D polymer. It possesses a 5,6-connected btv topology with a vertex symbol of (4(7).6(2).8)(2)(4(10).6(5)), which is rarely observed but only predicted by O'Keeffe in theory in coordination polymers. Compound [Cd-7.5(atz)(9)(mu(3)-SO4)(2)(mu(3)-OH)(2)](n)center dot 4.5H(2)O (4) is a 3D coordination polymer with a 3,4-connected (8(3))(4)(8(6))(3) topology, which is built from trinuclear [Cd-3(mu(3)-SO4)(mu(3)-OH)] clusters and bridging mononuclear Cd centers. Compound [Cd-5(atz)(4)(mu(5)-SO4)(2)(mu(3)-OH)(2)](n) (5) is constructed by a 3D inorganic cationic [Cd-5(mu(5)-SO4)(2)(mu(3)-OH)(2)](n)(4+) network, a 6-connected pcu topology, templated by atz(-) anions. The anion-exchange experiments were performed successfully for 1 and 3. Moreover, the thermal stabilities and photoluminescent properties of these compounds were investigated. This work markedly indicates that the subtle changes in the synthesis conditions profoundly influence the structures and topologies of the products.