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

Abstract

Eleven compounds, [Zn(L¹)₂(bbmi)] (1), [Zn(HL²)₂(bbmi)] (2), [Zn_0.5(L³)(bbmi)_0.5] (3), [Zn_0.5(L⁴)(bbmi)_0.5(H₂O)] (4), [Zn(L⁵)₂(bbmi)] (5), [Zn(L⁶)(bbmi)] (6), [Zn(L⁷)(bbmi)_0.5(H₂O)] (7), [Zn(L⁸)(bbmi)_0.5(H₂O)] (8), [Ag₂(L⁶)(bbmi)(H₂O)] (9), [Ag(L⁹)_0.5(bbmi)_0.5]·2H₂O (10) and [Ag_2.5(L¹⁰)(bbmi)₂]·0.5(OH)·0.5(EtOH)·1.5H₂O (11), where bbmi = 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole), HL¹ = benzoic acid, H₂L² = salicylic acid, HL³ = p-nitrobenzoic acid, HL⁴ = nicotinic acid, HL⁵ = 3,5-dinitrobenzoic acid, H₂L⁶ = o-phthalic acid, H₂L⁷ = m-phthalic acid, H₂L⁸ = fumaric acid, H₂L⁹ = p-phthalic acid and H₂L¹⁰ = 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⋯π interactions to yield a 3D supramolecular structure. There exist weak Ag⋯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 α-Po framework. Compound 9 displays a 2D layer structure. Furthermore, the π–π interactions among the bbmi ligands link the layers into a 3D supramolecular framework. Compound 11 shows a ladder structure. The Ag⋯Ag and π–π 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.