標題: | The Role of the n pi* (1)A(u) State in the Photoabsorption and Relaxation of Pyrazine |
作者: | Lin, Chih-Kai Niu, Yingli Zhu, Chaoyuan Shuai, Zhigang Lin, Sheng Hsien 應用化學系 Department of Applied Chemistry |
關鍵字: | absorption;pyrazines;quantum chemistry;excited states;vibronic coupling |
公開日期: | 4-十一月-2011 |
摘要: | The geometric, energetic, and spectroscopic properties of the ground state and the lowest four singlet excited states of pyrazine have been studied by using DFT/TD-DFT, CASSCF, CASPT2, and related quantum chemical calculations. The second singlet n pi* state, (1)A(u), which is conventionally regarded dark due to the dipole-forbidden (1)A(u) <- (1)A(g) transition, has been investigated in detail. Our new simulation has shown that the state could be visible in the absorption spectrum by intensity borrowing from neighboring n pi* (1)B(3u) and pi pi* (1)B(2u) states through vibronic coupling. The scans on potential-energy surfaces further indicated that the (1)A(u) state intersects with the (1)B(2u) states near the equilibrium of the latter, thus implying its participation in the ultrafast relaxation process. |
URI: | http://dx.doi.org/10.1002/asia.201100472 http://hdl.handle.net/11536/14937 |
ISSN: | 1861-4728 |
DOI: | 10.1002/asia.201100472 |
期刊: | CHEMISTRY-AN ASIAN JOURNAL |
Volume: | 6 |
Issue: | 11 |
起始頁: | 2977 |
結束頁: | 2985 |
顯示於類別: | 期刊論文 |