4-氟苯酚分子在S1←S0跃迁过程中分子构型和振动频率的变化研究

The Study on the Changes of Molecular Configuration and Vibrational Frequency of 4-Fluorophenol During S1←S0 Transition

文章利用从头算法(ab initio)和密度泛函理论(DFT)计算得到4-氟苯酚(FPO)分子在S1←S0跃迁过程中分子构型和振动频率的变化。FPO分子在S1←S0跃迁过程中键长和键角的变化表明π*←π的激发使得苯环发生了扩张,取代基羟基(OH)和氟原子(F)与苯环的相互作用在S1←S0的跃迁中发生了变化。FPO分子的振动模式在S1态的频率值普遍低于其在S0态时的频率值,这说明FPO分子的结构在S0态的刚性强于在S1态的刚性。

The changes of molecular configuration and vibrational frequency of 4-Fluorophenol(FPO)molecule during S1←S0 transition are obtained by using ab initio and density functional theory(DFT)calculations.The changes of bond length and bond angle of FPO during S1←S0 transition indicates that the π*←π transition lead to an expansion of the aromatic ring and the interaction of substituents OH and F with benzene ring has changed during S1←S0 transition.The vibrational frequencies of vibrational modes in S1 state are lower than those in S0 state,which suggests that the geometrical configuration of FPO is more rigid in S0 state than in S1 state.