Resonance Raman spectroscopy is a technique that enhances Raman scattering intensity when the laser excitation frequency matches an electronic transition of the compound being examined. This resonance effect can greatly increase the intensity of Raman bands, facilitating the study of compounds present at low concentrations. The intensity is directly proportional to the energy difference between the laser and electronic transition. The theory of resonance Raman is complex as the normal polarizability theory fails under resonance conditions. It allows selective study of specific parts of molecules and is useful for problems in biology and complexes materials.

1. guided By :-Dr. Rachna Dube
.
presented by:-varsha tidke
Resonance Raman
spectroscopy

2. RAMAN SPECTOSCOPY
Raman spectroscopy is based on scattering of
radiation (Raman scattering), which is a
phenomenon discovered in 1928 by physicist Sir C.
V. Raman.

3. RASONANCE RAMAN SPECTROSCOPY
 when the incident laser frequency is close in
energy to an electronic transition of a
compound or crystal under examination.The
frequency coincidence (or resonance) can lead
to greatly enhanced intensity of the Raman
scattering, which facilitates the study
of compounds present at low concentrations.[

6. The Raman intensity is directly proportional to (Ve-
V0) asV0 approach to the denominator is become
very small. Hence , this term (“resonance term”)
become so large that the intensity of the Raman
band at (Ve-V0) increase enormously
How intensity is enhanced?

7. Absorption spectra of compound contain
two chromophoric (A and B)

8. theory
 The theory of resonance Raman effect is
much complex .
 The polarizability theory fails under
resonance condition
 The selection rule appearance of overtone
 Only totally symmetric fundamental may
show the effect

9. Overtone band

10. Fundamental and overtone
band

11. Rss active or inactive

12. Technique
 The experimental setup for RSS is same as
that used for normal Raman spectroscopy.
 Gas lasers or tunable dye lasers are used for
excitation.
 The effect of over heating can be prevented
by spinning the sample rapidly

13. application
 enharmonic and harmonic frequency is accurately
determine .
 RSS is well suited for the study of free radical and
transient species.
 It represent a great simplification which is focus
directly on specific part of the molecule.
 It is used for studding biostructural problem and
complex biological material.
 Excitation profile of Raman show close relationship
b/w Raman and electronic spectroscopes.

14. Thankyou