By Wu Guozhen
World Scientific
In this book the author offers an overview of Raman spectroscopy techniques – including Raman optical activity (ROA) and surface-enhanced Raman scattering spectroscopy (SERS) – covering their applications and their theoretical foundations.
The Raman effect is an inelastic two-photon process in which the incident (scattering) photon is absorbed by an atom or molecule (the scatterer) that immediately emits a photon of different energy and frequency than the incident one. This energy difference, which arises because the incident photon vibrationally excites the molecule, is called the Raman shift. Raman shifts provide information on the molecular motion and thus its structure and bond strength. As a consequence, this effect is used for material analysis in Raman spectroscopy.
More important than the energy difference are the Raman intensity of the scattered light, which offers insights into the dynamics of the photon-perturbed molecule, and the electronic polarisability of the molecule, which is a measure of how easily the electrons can be affected by the light.
After introducing the Raman effect and the normal mode analysis, the author discusses the bond polarisabilities, the intensity analysis and the Raman virtual states. A group of chapters then cover the extension of the bond polarisability algorithm to the ROA intensity analysis and many findings on ROA mechanism resulting from the work of the author and his collaborators. The last chapter introduces a unified classical theory for ROA and vibrational circular dichroism (another spectroscopic technique).
