Infra Red Spectrometry:

You have studied about the UV-VIS spectrometry    an important analytical tool that involves the measurement of the consequence of interaction of electromagnetic radiation in the UV and/or visible regions with the molecules, ions or complexes. The spectra so obtained could be utilized to study the presence, nature and the amount of chromophores in a molecule.

In this unit, we take up the study of infra red (IR) spectrometry-another common spectroscopic technique used by organic and inorganic chemists for structure elucidation and compound identification. We shall starts through understanding the theory behind IR spectroscopy in terms of the origin of the spectrum, the types and number of vibration modes possible in a molecule and the characteristic features of an IR spectrum. It will be followed by a brief account of the essential components of an IR spectrometer and different types of IR spectrometers with their principles, advantages and disadvantages. Thereafter we shall discuss the applications of IR spectrometry in diverse areas. In the next unit, we shall take up the study of Raman spectrometry another important spectroscopic method of analysis.

Objectives

After studying this unit, you should be able to:

• Elaborates the origin of IR spectrum,
• Compute the vibrational degrees of freedom for different polyatomic molecules,
• Define different types of vibrational modes of molecules,
• Recognize the IR active and inactive modes of vibration for small molecules,
• Elaborates the reasons for the complex nature of IR spectrum,
• Define briefly the components of IR instruments,
• Elaborate the principles of different types of IR instruments,
• Contrast and contrast different types of instruments in terms of their principles and applications, and
• List and Elaborates different applications of IR spectrometry.