Synthesis, Crystal Structure, and Luminescence of Zn/Cd Coordination Polymers with a New Fuctionalized Terpyridyl Carboxylate Ligand

Eight new coordination polymers, [Zn(L)Cl](n) (1), [Zn-2(L)(4)](n)center dot 2nH(2)O (2), [Zn-2(L)(2)(1,3-bdc)](n) (3), [Zn-2(L)(1,3-bdc)(OH)](n)center dot 0.5nH(2)O (4), [Zn-9(L)(4)(1,3-bdc)(6)(OH)(2)](n)center dot 3nH(2)O (5), [Zn-2(L)(2)(1,4-bdc)](n)center dot nH(2)O (6), [Cd-2(L)(4)](n)center dot nH(2)O (7), and [Cd-3(L)(2)(1,3-bdc)(2)](n)center dot nH(2)O (8) [HL = 4'-(2-carboxyphenyl)-4,2':6',4 ''-terpyridine, H-2(1,3-bdc) = benzene-1,3-dicarboxylic acid, H-2(1,4-bdc) = benzene-1,4-dicarboxylic acid] have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, and single crystal X-ray diffraction. Complexes 1, 2, and 7 display a two-dimensional (2D) layer structure. Complex 3 presents a complicated 2D layer structure with paddle-wheel units, which exhibits an interesting (3,4,6)-connected 3-nodal new topological net with the point symbol of (3.4.5.6(2).7)(2)(3.6.7)(2)(3(2).4(2).5(2).6(2).7(6).8). Complex 4 is a 2-nodal (3,5)-connected 2D bilayer structure with the gek1 topological net and the point symbol of (34.5)(3(2).4.5.6(2).7(4)). Complex 5 shows a self-penetrating three-dimensional (3D) framework based on pentanuclear clusters, which features an intriguing (3,3,4,4,12)-connected 5-nodal new topological net with the point symbol of (4.6(2))(2)(4(2).6(4))(4)(4(3))(2)(4(8).6(34).8(22).10(2)). Complex 6 features a 2-fold interpenetrating (3,4)-connected 3D framework with the ins topological net and the point symbol of (6(3))(6(5).8). Complex 8 is a new (4,4,5,6)-connected 3D network built up by a linear Cd-3(COO)(6) trinuclear cluster with the point symbol of (4(2).6(3).8)(2)(4(3).6(3))(2)(4(4).6(4).8(2))(2)(4(8).6(6).8). The diverse structures indicate that rational adjustment of the second ligand, the pH value, and counteranion are good methods to further design metal-organic compounds with new structures and properties. In addition, the thermal stabilities and photoluminescence properties of 1-8 were also studied.