Resonance Raman Intensity Analysis of the A Band Short-Time Photochemical Dynamics of 4,5-Ethylenedithio-1,3-dithiole-2-thione

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• 作者：Huigang Wang ; Wenfei Zhang ; Bo Liu ; Shaosong Shen ; Xuming Zheng ; Kemei Pei ; Lijiang Chen
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：December 22, 2011
• 年：2011
• 卷：115
• 期：50
• 页码：14282-14291
• 全文大小：952K
• 年卷期：v.115,no.50(December 22, 2011)
• ISSN：1520-5215

文摘

Resonance Raman spectra (RRs) for 4,5-ethylenedithio-1,3-dithiole-2-thione (EDDT) were obtained with 397.9 and 416 nm excitation wavelengths, and density functional calculations were performed to elucidate the electronic transitions and the RRs of EDDT in chloroform solvent. The RRs indicate that the Franck鈥揅ondon region photodynamics have multidimensional character with nuclear motion predominantly along the C₄鈺怌₅ stretch and the C₄鈺怌₅ twist out-of-plane. Resonance Raman cross-sections of A-band absorption have been obtained for the vibrational modes of EDDT with its excitation frequencies spanning the 408 nm. Resonance Raman intensity analysis of the resulting RRs excitation profiles and absorption spectrum using a time-dependent wave packet formalism yields mode-specific nuclear displacement and vibrational reorganizational energies. The intensity analysis results for EDDT were compared to previously reported results for dimethyl 1,3-dithiole-2-thione-4,5-dicarboxylate (DDTD), which shows that the additional six-member heterocycle of EDDT strongly affects the reorganizational energy and energy participation. The authors briefly discuss the differences and similarities of the spectra in terms of molecular symmetry and electron density.