Excited State Structural Dynamics of Tetra(4-aminophenyl)porphine in the Condensed Phase: Resonance Raman Spectroscopy and Density Functional Theory Calculation Study

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• 作者：Huigang Wang ; Jun Xu ; Junmin Wan ; Yanying Zhao ; Xuming Zheng
• 刊名：Journal of Physical Chemistry B
• 出版年：2010
• 出版时间：March 18, 2010
• 年：2010
• 卷：114
• 期：10
• 页码：3623-3632
• 全文大小：421K
• 年卷期：v.114,no.10(March 18, 2010)
• ISSN：1520-5207

文摘

Resonance Raman spectra (RRs) of tetra(4-aminophenyl) porphine (TAPP) were obtained, and density functional calculations were done to help the elucidation of the photorelaxation dynamics of Soret (B_x and B_y band) and Q_y electronic transitions. The RRs indicate that the photorelaxation dynamics for the S₀ → S₃ excited electronic state is predominantly along the totally symmetric porphin ring C_β═C_β + C_mC_α stretch, C_m−ph stretch, and simultaneously along the asymmetric ν(C_mC_α)_as and ν(C_αC_β)_as relaxation processes leading to Q_y while that for S₀ → S₂ is predominantly along the porphin ring C_β═C_β + C_mC_α stretch and simultaneously along the asymmetric ν(C_mC_α)_as + ν(C_αC_β)_as relaxation processes leading to thermal equilibrium in Q_x. The excited state structural dynamics of TAPP determined from RRs shows that internal conversion B_x → Q_y electronic relaxation occurs in tens of femtoseconds and the short-time dynamics were first interpreted with account of the time-dependent wave packet theory and Herzberg−Teller contributions.