Four cluster-containing highly connected coordination networks: syntheses, structures, and properties

Four three-dimensional highly connected coordination polymers, [Zn-4(4-O)(L)(2)(btbp)(1.5)] (1), [Zn-8(3-OH)(4)(L)(4)(btb)(H2O)2] (2), [Cd-8(3-OH)(4)(L)(4)(4,4'-bipy)(H2O)4] H2O (3) and [Cd-5(L)(2)(ipt)(4)(H2O)(2)](6)H2O (4), where H3L = (3,5-dicarboxyl-phenyl)-(4-(2'-carboxyl-phenyl)-benzyl) ether, btbp = 4,4'-bis(1,2,4triazol- 1- ylmethyl) biphenyl, btb = 1,4-bis( 1,2,4-triazol-1-yl) butane, 4,4'-bipy = 4,4'-bipyridine and Hipt = 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole, have been synthesized under hydrothermal conditions. In complex 1,9-connected tetranuclear [Zn-4(mu(4)-O)(COO)(6)] clusters are bridged by L anions and btbp ligands to form a (3,3,9)- connected network. Complexes 2 and 3 possess (3,3,14)- connected nets based upon octanuclear [Zn-8(mu(3)-OH)(4)(COO)(12)] and [Cd-8(mu(3)-OH)(4)(COO)(12)(6H(2)O) 4] clusters, respectively. Complex 4 reveals a tetranodal (3,4,8)- connected network based on trinuclear [Cd-3(COO)(2)(H2O)(2)] units. Additionally, the fluorescence properties of complexes 1-4 were investigated.