Essay On Infrared Spectroscopy

INFRARED SPECTROSCOPY:

Definition:

It is defined as the spectroscopy that is concerned with the infrared region of electromagnetic energy spectrum. As the name suggests, this type of spectroscopy is used to study the interaction of light of low wavelength with matter. IR spectroscopy deals with the vibrational energy of atoms, and thus determines the functional groups.

Theory:

An infrared spectrum is obtained when infrared light passes through the given sample, and finds out the amount of incident radiation absorbed by the sample. Infrared light directly does not cause electrons to shift to higher energy states , but it has enough energy to undergo interaction with a molecule and alter its vibration and rotation. The molecules under consideration absorb only certain frequencies, which are characteristic of their structure. The frequency absorbed by the molecules is equal to the energy difference of two transition states. The molecule thus becomes excited and thus expedites its rotation and vibration. The

This is due to the fact that numerous absorption bands are observed in the infrared spectra of organic substances, hence the probability of any two or more compounds having the same spectrum is negligible.

2.) This type of spectroscopy is used to determine the progress of a chemical reaction by extracting small portions from the mixture after every few intervals. The formation of a product is marked by the disappearance rate of an absorption band of a reactant or by the rate of appearance of the product’s characteristic absorption band.

3.) Impurities can also be detected with the help of infrared spectroscopy. The spectrum of a compound/sample which is to examined, is compared to that of the standard compound. Irregular, and additional peaks indicate impurities present in the