The origin of anti-resonance in preresonance Raman scattering

✍ Scribed by S. Hassing

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 587 KB
• Volume: 28
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199710)28:10<739::aid-jrs111>3.0.co;2-u

✦ Synopsis

The anti-resonance phenomenon in Raman scattering was studied in the preresonance region of an allowed electronic transition. It is shown that the anti-resonance in the scattering of both totally and non-totally symmetric modes can be explained in terms of an analytical model. The necessary and general conditions for obtaining an anti-resonance are derived. The importance of comparing resonance and preresonance data (showing the antiresonance e †ect), in order to obtain reliable molecular parameters from the experiments, is demonstrated. For both totally and non-totally symmetric modes it is shown that, depending on the nature and number of the electronic states that contribute to the scattering, the anti-resonance in the excitation proÐle may be followed by a dramatic dispersion in the depolarization ratio. By comparing model calculations of the depolarization ratio and the excitation proÐle with experimental data, it is shown that both of these quantities are needed in order to discriminate between di †erent theoretical models.