Resonance Raman Spectroscopic and Theoretical Investigation of the Excited State Proton Transfer Reaction Dynamics of 2-Thiopyridone

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• 作者：Rui Du ; Chong Liu ; Yanying Zhao ; Ke-Mei Pei ; Hui-Gang Wang ; Xuming Zheng ; Mingde Li ; Jia-Dan Xue ; David Lee Phillips
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：June 30, 2011
• 年：2011
• 卷：115
• 期：25
• 页码：8266-8277
• 全文大小：1020K
• 年卷期：v.115,no.25(June 30, 2011)
• ISSN：1520-5207

文摘

The resonance Raman spectra were obtained for both 2-thiopyridone (2TP) and its proton-transfer tautomer 2-mercaptopyridine (2MP) in water solution. Density functional theory (DFT) calculations were carried out to help elucidate their ultraviolet electronic transitions and vibrational assignments of the resonance Raman spectra associated with their B-band absorptions. The nanosecond time-resolved resonance Raman spectroscopic experiment was carried out to further confirm the assignment that the transient species was the ground state 2MP. The different short-time structural dynamics were examined for both 2TP and 2MP in terms of their resonance Raman intensity patterns. The transition barriers between 2TP and 2MP for S₀, T₁, and S₁ states are determined by using (U)B3LYP-TD and CASSCF level of theory computations, respectively. The excited state proton transfer (ESPT) reaction mechanism is proposed and briefly discussed.