摘要
A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analyses, fluorescence spectrum, and thermogravimetric analysis. In compound 1, the [mpba]＋ cation is a new organic template, which is obtained firstly in this work by in situ alkylation reaction of N-heterocycles 4-（pyridin-4-yl）benzoic acid with [Emim]Br（Emim = 1-ethyl-3-methyl imidazolium）. Hirshfeld surface analysis shows that weak interactions between the [mpba]＋ cations and 1D inorganic [Cu_2Br_3]~– are mainly C–H···Br hydrogen bonds. In addition, a pairwise O–H···O interaction is observed between the adjacent [mpba]＋cations. These different types of weak interactions make compound 1 stable up to 300 ℃. Fluorescence spectrum investigation shows 1 has a strong yellow emission at 555 nm. Theoretical calculation not only demonstrates compound 1 is a wild band semiconductor with a 3.3 e V band gap but also elucidates the fluorescence emission derives from the p-π＊ transition of electrons from [Cu_2Br_3]~– to [mpba]~＋.
A new compound [mpba][Cu_2Br_3]（1, mpba = 4-（N-methylpyridin-4-yl）benzoic acid） has been ionothermally synthesized and characterized by single-crystal X-ray diffraction analysis, infrared spectrum, elemental analyses, fluorescence spectrum, and thermogravimetric analysis. In compound 1, the [mpba]＋ cation is a new organic template, which is obtained firstly in this work by in situ alkylation reaction of N-heterocycles 4-（pyridin-4-yl）benzoic acid with [Emim]Br（Emim = 1-ethyl-3-methyl imidazolium）. Hirshfeld surface analysis shows that weak interactions between the [mpba]＋ cations and 1D inorganic [Cu_2Br_3]~– are mainly C–H···Br hydrogen bonds. In addition, a pairwise O–H···O interaction is observed between the adjacent [mpba]＋cations. These different types of weak interactions make compound 1 stable up to 300 ℃. Fluorescence spectrum investigation shows 1 has a strong yellow emission at 555 nm. Theoretical calculation not only demonstrates compound 1 is a wild band semiconductor with a 3.3 e V band gap but also elucidates the fluorescence emission derives from the p-π＊ transition of electrons from [Cu_2Br_3]~– to [mpba]~＋.
基金
supported by the Natural Science Foundation of Fujian Province(No.2014J01029)
