Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, PL-01-224 Warsaw, Poland.
J Chem Phys. 2011 Jul 21;135(3):034307. doi: 10.1063/1.3609759.
Excited-state intramolecular proton transfer (ESIPT) reaction has been studied in a molecule showing dual fluorescence, the 2,5-bis(2-benzoxazolyl)-4-methoxyphenol (BBMP), and its isotopomers, where the methoxy, and alternatively, the OH group has been deuterated. Attention is focused on the influence of electron donating OCH(3) substituent on fast excited state reaction. Comparison between the resonance-enhanced multiphoton ionization spectrum and the laser-induced excitation of the primary and phototautomeric emissions has been done. The geometry, electron density distribution, vibrational structure as well as the potential energy profiles in the S(0) and S(1) states of four possible rotameric forms of BBMP were calculated with application of the density functional theory (DFT). It allowed identifying the most probable conformer and assessing the role of low-frequency motions for the ESIPT efficiency.
激发态分子内质子转移（ESIPT）反应已在一种表现出双重荧光的分子中进行了研究，该分子为 2,5-双（2-苯并恶唑基）-4-甲氧基苯酚（BBMP）及其同位素，其中甲氧基和 OH 基团被氘取代。关注的焦点是供电子 OCH(3)取代基对快速激发态反应的影响。对共振增强多光子电离光谱和激光诱导的初级和光互变异构发射的激发进行了比较。应用密度泛函理论（DFT）计算了 BBMP 的四种可能的构象异构体在 S(0)和 S(1)态的几何形状、电子密度分布、振动结构以及势能分布。这允许识别最可能的构象，并评估低频运动对 ESIPT 效率的作用。
