Ultraviolet-Visible Spectroscopy or electronic spectroscopy

Ultraviolet-Visible Spectroscopy or electronic spectroscopy

The study of the electronic transitions among the energy levels of the molecules as a result of the absorption of electro-magnetic radiations is called Ultraviolet-Visible Spectroscopy or electronic spectroscopy as the electronic transitions require energy in this region. The electronic transitions in the UV-vis spectroscopy_. take place in the region between 10 nm. to 800 nm. The region from 10 nm. to 400 nm is the ultraviolet region whereas the region from 400 nut to 800 nm. is the visible region. The UV region consists of two parts:

(1)      FAR ULTRAVIOLET REGION: This region extends from 10 nm to 200 nm. In this region oxygen absorbs, so it may interfere the analysis of the spectrum. To avoid it the system must be evacuated. Therefore it is called vacuum ultraviolet region.

(2)      NEAR ULTRAVIOLET REGION: This region extends from 200 nm to 400 nm. It is also called ordinary or quartz ultraviolet region as the atmosphere does not absorb in this region.