An anionic metal–organic framework based on infinite [In3(μ3-OH)2]n inorganic chains synthesized in ionic liquid

A 3D metal–organic framework, namely, {[EMIM][In3(μ3-OH)2(1,2,4,5-BTC)2∙2H2O]}n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized by using 1-ethyl-3- methylimidazolium bromide ([EMIM]Br) ionic liquid as solvent. The 7-coordinated pentagonal bipyramidal In(1) and octahedral In(2) atoms are connected by the μ3-OH groups to form an infinite [In3(μ3-OH)2]n inorganic chain along the a-axis, which are further extended by 1,2,4,5-BTC ligands to generate the 3D anionic microporous framework of 1. The [EMIM]+ cations occupy the 1D channels acting as template and charge-balancing species. Compound 1 shows strong blue luminescence and remarkable photocatalytic degradation of methylthionine chloride.