Infrared Spectroscopy : Principle & Instrumentation

Accurate compound purity determination is crucial across many industries, even when dealing with trace amounts. Conventional methods often fall short, necessitating sophisticated analytical techniques. Spectroscopy stands out as a powerful tool for analyzing compounds at the ppb (parts per billion) or ppm (parts per million) level.

There are two main types of spectroscopy: Absorption Spectroscopy and Emission Spectroscopy. Infrared Spectroscopy (IR Spectroscopy) is a prominent example of absorption spectroscopy. It focuses on the infrared region of the electromagnetic spectrum – light with longer wavelengths and lower frequencies than visible light. Essentially, IR spectroscopy analyzes how a molecule interacts with infrared light.

The core concept of IR spectroscopy involves measuring reflection, emission, or absorption of infrared light. Its primary application lies in identifying functional groups within molecules, making it invaluable in both organic chemistry and inorganic chemistry.

An IR spectrum is a graph plotting infrared light absorption against frequency or wavelength. IR Spectroscopy works by detecting frequencies of infrared light absorbed by a molecule. Molecules selectively absorb specific frequencies because these correspond to the vibrational frequencies of their chemical bonds.

Infrared radiation (IR), also known as thermal radiation, occupies the portion of the electromagnetic spectrum between red visible light and 1 mm in wavelength (approximately 780 nm to 1 mm).

This course delves into the fundamental theory of spectroscopy, the principle of IR spectroscopy, and the various types of vibrations that occur in molecules after absorbing IR radiation. We'll explore the vibration of diatomic and polyatomic molecules, the criteria for IR absorption, the instrumentation used in IR spectroscopy, the components of an IR spectrum, and its diverse applications. Learn how to utilize IR spectroscopy for precise molecular analysis.