title: The investigation of excited state proton transfer mechanism in water-bridged 7-azaindole.
abstract: Based on the time-dependent density functional theory (TDDFT), the excited-state intermolecular proton transfer (ESIPT) mechanism of water-bridged 7-azaindole has been investigated theoretically. The calculations of primary bond lengths and the IR vibrational spectra between the S0 state and the S1 state that verified the intramolecular hydrogen bond were strengthened. The fact that reproduced experimental absorbance and fluorescence emission spectra well theoretically demonstrate that the TDDFT theory we adopted is reasonable and effective. In addition, intramolecular charge transfer based on the frontier molecular orbitals demonstrated the indication of the ESIPT reaction. The constructed potential energy curves of ground state and the first excited state based on keeping the H2···O3 and H6···N7 distances fixed at a series of values have been used to illustrate the ESIPT process. A relative lower barrier of 5.94 kcal/mol in the S1 state potential energy curve for type II (lower than that of 9.82 kcal/mol in the S1 state for type I) demonstrates that type II ESIPT process occurs firstly in 7Al-2H2O complex.
authors: Department of Physics, Liaoning University, Shenyang 110036, PR China.
authors: Yong-Jia
authors: YJ
authors: Zhang
authors: Department of Physics, Liaoning University, Shenyang 110036, PR China; State Key Lab of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
authors: Jin-Feng
authors: JF
authors: Zhao
authors: Department of Physics, Liaoning University, Shenyang 110036, PR China; State Key Lab of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China. Electronic address: yqli@lnu.edu.cn.
authors: Yong-Qing
authors: YQ
authors: Li
keywords: Electronic spectra; Excited-state intermolecular proton transfer; Frontier molecular orbitals; Potential energy curves