A density functional theory-derived force field for 3-ethylindole. Use of the ultraviolet resonance Raman intensities to check the vibrational analysis accuracy

✍ Scribed by H. Gallouj; P. Lagant; G. Vergoten

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 256 KB
• Volume: 29
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199805)29:5<343::aid-jrs237>3.0.co;2-6

✦ Synopsis

The vibrational wavenumbers of 3-ethylindole were obtained from ab initio studies based on the density functional theory (DFT) approach. The assignments of the theoretical wavenumbers obtained after scaling of the internal force constants were compared with those of skatole and tryptophan. To check the derived ab initio force Ðeld validity, the resonance Raman intensities were obtained from the changes in bond orders occurring along the lowest lying p Ç p* electronic transitions and using the A-term part of the scattering tensor. It is shown (L b , L a B a , B b ) that the vibrational assignments are in accordance with calculated resonance Raman intensities and previous work on tryptophan.