Excited-state intramolecular proton transfer and charge transfer in 2-(2′-hydroxyphenyl)benzimidazole crystals studied by polymorphs-selected electronic spectroscopy
Excited-state intramolecular proton transfer and charge transfer in 2-(2′-hydroxyphenyl)benzimidazole crystals studied by polymorphs-selected electronic spectroscopy
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DOI：
10.1039/c2cp42686b
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发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Sekiya, Hiroshi
中科院分区：
文献类型：
--
作者：
Konoshima, Hayato;Nagao, Saori;Sekiya, Hiroshi
通过X射线晶体学分析2-（2 '-羟基苯基）苯并咪唑（HPBI）的多晶型物（形式α和β）的晶体结构。在77-298 K温度下分别观察到了多晶型物的荧光激发光谱和荧光光谱。已发现两种晶型的电子光谱彼此显著不同。α型和β型中烯醇形式的光激发诱导激发态分子内质子转移（ESIPT）以产生酮形式的S-1态。在形式α和β的FE光谱中，S-1
Crystal structures of polymorphs of 2-(2'-hydroxyphenyl) benzimidazole (HPBI), Forms alpha and beta, are analyzed by X-ray crystallography. The fluorescence excitation (FE) and fluorescence spectra of the polymorphs are separately observed at temperatures 77-298 K. It has been found that the electronic spectra of the two crystal forms are significantly different from each other. Photo-excitation of the enol forms in Forms alpha and beta induces the excited-state intramolecular proton transfer (ESIPT) to produce the S-1 state of the keto forms. In the FE spectra of Form alpha and beta, the S-1