Theoretical study on geometry and spectroscopic properties of 1,1′-binaphthyl in the electronic ground and first excited singlet states |
| |
Authors: | K Gustav J Sühnel UP Wild |
| |
Institution: | Sektion Chemie, Friedrich-Schiller-Universität, Jena, DDR;Laboratorium für Physikalische Chemie der ETH, Zürich, Switzerland |
| |
Abstract: | Equilibrium geometries for the electronic ground and first excited singlet states of 1,1'-binaphthyl have been calculated by minimization of the total energy with respect to all internal coordinates. Using these results, an interpretation of the fluorescence S1→ S0 and absorption spectra Sm ← S0 and Sn ← S1 in rigid and fluid solutions is given.For the first time the equilibrium geometry of the first excited singlet state of 1, 1′-binaphthyl has been calculated. On excitation to the S1 state the dihedral angle θ between the two naphthalene moieties is de- creased from 61 ° to 41 °. A detailed survey of CH bond lengths in the S0 and S1 states has been given. This result should be of particular importance for the theoretical treatment of radiationless transitions.Using equilibrium geometries for the S0 and S1 states a satisfactory interpretation of the Sm ← S0 and Sn ← S1 absorption spectra as well as of the fluorescence spectra in fluid and rigid solutions can be given. Concerning the Sn ← S1 absorption spectrum in fluid solution, the calculations predict a strong absorption (A ← B transition) in the still uninvestigated region of energies lower than 11000 cm?1.From the results of this paper and of other calculations it can be concluded that the Warshel-Karplus method yields reliable equilibrium geometries for electronic ground and excited states of unsaturated hydrocarbons 22,23]. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|