光致电子转移对Rhodamine 6G基态分子结构影响的非共振Raman光谱研究

基于非共振Raman 光谱和量子化学计算, 研究了在纯电子给体N,N-二乙基苯胺(DEA)溶剂中Rhodamine 6G (Rh6G⁺)基态分子结构的变化, 这有利于理解该体系中的光致分子间电子转移(PIET). 与PIET相耦合的所有振动模式已被确定和指认. 结果表明: 对应于氧杂蒽环且位于675 cm^-1处最主要的振动模式对PIET 有着至关重要的贡献; 通过与电荷转移复合物(Rh6G/DEA⁺)的发色团芳香族环的C―C伸展振动模式作比较, C=C伸展振动对PIET的影响更敏感. 本文的研究工作能为具有合适电子转移特性的光伏器件中分子结构或溶剂环境的设计提供新颖的观点.

Influence of Photoinduced Electron Transfer on the Ground-State Molecular Structure of Rhodamine 6G Determined by Nonresonance Raman Spectroscopy

Changes of the ground-state molecular structure of rhodamine 6G (Rh6G⁺) in pure electron donor solvent N,N-diethylaniline (DEA) were investigated by nonresonance Raman spectroscopy and quantum chemical calculations to help understand photoinduced intermolecular electron transfer (PIET) in this system. All of the vibrational modes coupled to PIET were determined and assigned. The results indicate that the most prominent vibrational mode at 675 cm^-1, corresponding to the in-plane bending of the xanthene ring, strongly contributes to PIET. Compared with the C―C stretching mode, the C=C stretching vibration of the chromophore aromatic ring of the Rh6G/DEA⁺ charge-transfer complex is more sensitive to PIET. This work provides new insight for designing molecular structures or solvent environments with desirable electron transfer properties for use in photovoltaic devices.