A Series of Coordination Polymers Constructed by Flexible 4-Substituted Bis(1,2,4-triazole) Ligands and Polycarboxylate Anions: Syntheses, Structures, and Photo luminescent Properties

Eleven Zn/Cd-containing coordination polymers (CPs) incorporating both flexible 4-substituted bis(1,2,4-triazole) ligands and polycarboxylate anions, namely, [Zn-(L1) (o-BDC)]center dot 1.5H(2)O (1), [Zn(L1)(m-BDC)] (2), [Cd-2(L1)(BTEC)]center dot H2O (3), [Zn(L2)(m-BDC)]center dot 1.25H(2)O (4), [Zn(L2)(p-BDC)]center dot 4H(2)O (5), [Cd(L2)(p-BDC)]center dot H2O (6), [Zn-2(L2)(BTEC)] (7), [Zn(L3)(m-BDC)]center dot 3.5H(2)O (8), [Zn-2(L3)(p-BDC)(2)}center dot 2H(2)O (9), [Zn-2(L3)(2)(BTEC)center dot 2H(2)O (10), and [Cd-2(L3)(2)(BTEC)} (11) {L1 = 1,2-bis[2-(4H-1,2,4-triazol-4-yl)phenoxy]ethane, L2 = 1,2-bis[3-(4H-1,2,4-triazol-4-yl)phenoxy]ethane, L3 = 1,2-bis[4-(4H-1,2,4-triazol-4-yl)phenoxy]ethane, o-H2BDC = phthalic acid, m-H2BDC = isophthalic acid, p-H2BDC = terephthalic acid, and H4BTEC = pyromellitic acid} have been prepared and identified by physical measurements. Compound 1 possesses a layered structure. Compound 2 shows one-dimensional chains. Weak pi-pi intermolecular stockings further join these chains into a two-dimensional (2D) supramolecular layered structure. Compound 3 displays a three-dimensional (3D) (4,8)-connected (3(2)center dot 4(2)center dot 5(2))(3(4)center dot 4(8)center dot 5(12)center dot 6(4),) net. Compound 4 consists of two interlocked single-wall metal-organic nanotubes (SWMONTs) with both polyrotaxane and polycatenane characters. Compound 5 exhibits a 3D 5-fold interpenetrating diamond motif. Compound 6 furnishes a 3D alpha-Po net. Compound 7 reveals a 3D (4,6)-connected net with (4(3)center dot 6(3))(4(6)center dot 6(6)center dot 8(3)) topology. Compound 8 features a 2D 4-connected network with (6(5)center dot 8) topology. Compound 9 shows a 3D 3-fold interpenetrating alpha-Po net. Compounds 10 and 11 display 3D (4,4)-connected nets with the same (6(4)center dot 7 center dot 8)(6(2)center dot 8(4)) topology. The effects of the bis(triazole) ligands, aromatic polycarboxylate anions, and metals ions on the framework assemblies have been discussed. Solid-state luminescent of compounds 1-11 are reported as well. Moreover, fluorescent properties of compounds 4-7 in various solvent suspensions were investigated at room temperature.