Ng Susan, Yarasi Soujanya, Brost Philip, Loppnow Glen R
Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
J Phys Chem A. 2007 Jun 21;111(24):5130-5. doi: 10.1021/jp071443t. Epub 2007 May 27.
To explore the excited-state structural dynamics of thymine, a DNA nucleobase, we measured the resonance Raman spectra of thymine in aqueous solution at wavelengths throughout the lowest-energy absorption band. Self-consistent analysis of the resulting resonance Raman excitation profiles and absorption spectrum using a time-dependent wave packet formalism yielded the excited-state structural dynamics. The photochemically relevant C=C stretching and C-H deformation vibrational modes were found to exhibit maximum resonance Raman intensity and structural change upon photoexcitation for thymine, suggesting that the initial dynamics of thymine lie along the photochemical reaction coordinate.
为了探究DNA核碱基胸腺嘧啶的激发态结构动力学，我们测量了胸腺嘧啶在水溶液中整个最低能量吸收带波长范围内的共振拉曼光谱。使用含时波包形式对所得的共振拉曼激发轮廓和吸收光谱进行自洽分析，得出了激发态结构动力学。发现与光化学相关的C=C伸缩振动和C-H变形振动模式在胸腺嘧啶光激发时表现出最大的共振拉曼强度和结构变化，这表明胸腺嘧啶的初始动力学沿着光化学反应坐标进行。
