Raman Spectroscopy: Understanding Intensity & Wave Number Peaks

In summary, the peaks in the graph in Raman spectroscopy represent Raman-active transitions in the vibrational energy states of a molecule. The peaks are caused by the pump wavelength plus or minus the energy of the vibrational transition, with stokes lines having lower energy and anti-stokes lines having higher energy.
  • #1
mkbh_10
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Tell me what do the peaks in the graph show which is b/w Intensity and wave number in raman spectroscopy ?

Are the peaks due to transition from a grnd state to an exicted state or vice versa , low energy are stokes and high energy are the anti stokes one
 
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will any1 reply
 
  • #3
The peaks are due to Raman-active transitions in the vibrational energy states; that is, transitions where there is a variation in the polarisability of the molecule. The peaks are the pump wavelength plus/minus the energy of the vibrational transition for anti-stokes/stokes lines.

For example, if I illuminate the sample with 442 nm radiation, the Raman signal is detected around (say) 460 nm. The difference in energy between the 442 and 460 nm photons is the energy of the vibrational transition.

Claude.
 

1. What is Raman Spectroscopy?

Raman Spectroscopy is a technique used in chemistry and physics to study the vibrational modes of molecules. It involves shining a laser on a sample and measuring the scattered light to determine the energy levels and vibrations of the molecules.

2. How does Raman Spectroscopy work?

Raman Spectroscopy works by exciting the molecules in a sample with a laser beam. When the laser light interacts with the molecules, some of the light is scattered at different wavelengths depending on the energy levels and vibrations of the molecules. This scattered light is then measured and analyzed to determine the molecular structure and composition of the sample.

3. What is the significance of intensity peaks in Raman Spectroscopy?

The intensity peaks in Raman Spectroscopy correspond to the amount of scattered light at different wavelengths. These peaks can reveal information about the molecular structure, such as the types of bonds present and their arrangement. The relative intensities of the peaks can also provide information about the concentration of certain molecules in the sample.

4. What do wave number peaks represent in Raman Spectroscopy?

Wave number peaks in Raman Spectroscopy represent the energy levels of the molecules in the sample. The position of these peaks on the spectrum can provide information about the vibrational modes and energy states of the molecules, which can help identify specific chemical bonds and functional groups.

5. What are some applications of Raman Spectroscopy?

Raman Spectroscopy has a wide range of applications in various fields, including chemistry, biology, pharmaceuticals, and materials science. It can be used to identify unknown substances, analyze the composition of materials, and monitor chemical reactions. It is also commonly used for quality control and forensic analysis.

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