Syntheses, structures and photoluminescence of zinc(II) and silver(I) coordination polymers based on 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole) and different carboxylate ligands

Eleven compounds, [Zn(L(1))(2)(bbmi)] (1), [Zn(HL(2))(2)(bbmi)] (2), [Zn(0.5)(L(3))(bbmi)(0.5)] (3), [Zn(0.5)(L(4)) (bbmi)(0.5)(H(2)O)] (4), [Zn(L(5))(2)(bbmi)] (5), [Zn(L(6))(bbmi)] (6), [Zn(L(7))(bbmi)(0.5)(H(2)O)] (7), [Zn(L(8)) (bbmi)(0.5)(H(2)O)] (8), [Ag(2)(L(6))(bbmi)(H(2)O)] (9), [Ag(L(9))(0.5)(bbmi)(0.5)]center dot 2H(2)O (10) and [Ag(2.5)(L(10))(bbmi)(2)]center dot 0.5(OH)center dot 0.5(EtOH)center dot 1.5H(2)O (11), where bbmi 1,1'-(1,4-butanediyl)bis(2-methylbenzimidazole), HL(1) = benzoic acid, H(2)L(2) = salicylic acid, HL(3) = p-nitrobenzoic acid, HL(4) = nicotinic acid, HL(5) = 3,5-dinitrobenzoic acid, H(2)L(6) = o-phthalic acid, H(2)L(7) = m-phthalic acid, H(2)L(8) = fumaric acid, H(2)L(9) = p-phthalic acid and H(2)L(10) = 5-aminoisophthalic acid, have been synthesized and characterized. Compounds 1-5 and 10 display one-dimensional chain structures. These chains are connected through intermolecular interactions to form 2D supramolecular structures, respectively. The layers of 2 are further connected through C-H center dot center dot center dot pi interactions to yield a 3D supramolecular structure. There exist weak Ag center dot center dot center dot Ag interactions in 10, which also contribute to the stabilization of the supramolecular layer. Compound 6 exhibits a diamondoid network. Compound 7 shows a 2D (4,4) layer. The structure of 8 is a 3D alpha-Po framework. Compound 9 displays a 2D layer structure. Furthermore, the pi-pi interactions among the bbmi ligands link the layers into a 3D supramolecular framework. Compound 11 shows a ladder structure. The Ag center dot center dot center dot Ag and pi-pi interactions further connect the ladders to form a 2D supramolecular assembly. The thermal stabilities of 4 and 7-11 and the luminescent properties of 1, 3-5 and 7-11 in the solid state are also discussed.