当前位置: X-MOL 学术Chem. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
On Raman optical activity sign-switching between the ground and excited states leading to an unusual resonance ROA induced chirality
Chemical Science ( IF 7.6 ) Pub Date : 2020-11-02 , DOI: 10.1039/d0sc05345g
Ewa Machalska 1, 2 , Grzegorz Zajac 2 , Malgorzata Baranska 1, 2 , Dorota Kaczorek 3 , Robert Kawęcki 3 , Piotr F J Lipiński 4 , Joanna E Rode 5 , Jan Cz Dobrowolski 5
Affiliation  

Raman optical activity (ROA) spectra recorded for a chiral naphthalene diimide derivative (nBu-NDI–BINAM) dissolved in a series of solvents exhibit strong solute to solvent induced chirality with: (1) dominating bands of solvents, (2) nBu-NDI–BINAM resonance ROA (RROA) bands which are barely visible, (3) monosignate RROA Solvent spectra with an unexpected sign concordant with that of the ECD band of the resonant electronic state, (4) bisignate RROA bands for a few solvents, and (5) superposition of non-resonant and resonant ROA bands of the chiral solvents. The unusual ROA enhancement was explained in terms of resonance energy transfer with resonant Raman emission. The surprising RROA sign-switching was found to be due to specific conformational equilibria where one solute conformer dominates in the ground and the other in the first excited singlet state, and, the signs of the related ECD bands of these two conformers are opposite.

中文翻译:

关于拉曼光学活性在基态和激发态之间的符号切换,导致不寻常的共振ROA诱导手性

溶解在一系列溶剂中的手性萘二酰亚胺衍生物(nBu-NDI-BINAM)的拉曼光学活性(ROA)光谱显示出强烈的溶质对溶剂诱导的手性,其中:(1)溶剂的主要谱带,(2)n几乎不可见的Bu-NDI-BINAM共振ROA(RROA)谱带,(3)单谱RROA溶剂光谱,其谱图与共振电子态ECD谱带的谱带出乎意料的符号,(4)几种溶剂的RROA谱双谱。 (5)手性溶剂的非共振和共振ROA带重叠。从共振能量转移与共振拉曼发射方面解释了ROA的异常提高。发现令人惊讶的ROROA符号转换是由于特定的构象平衡,其中一个溶质构象异构体在地下占主导,另一个在第一激发单重态下,而这两个构象异构体的相关ECD谱带的符号相反。
更新日期:2020-11-25
down
wechat
bug