Ultraviolet (UV) Spectroscopy

The discussion of Ultraviolet (UV) spectra is based on the characteristic absorption arising from the transition of different types of electrons in organic molecules. Mainly, there are three types of electrons s, p, and p electrons that are commonly encountered in organic molecules. Isolated auxochromic groups, such as hydroxyl and amino groups, show intense absorption in the far UV but no absorption in the UV region. However, the introduction of these groups to saturated systems gives rise to intense absorption at longer wavelengths. In modern chemical and biological laboratories, UV spectrophotometers are standard equipment. Essentially, there are two kinds of instruments on the market: single-beam and double-beam UV spectrophotometers. A hydrogen discharge tube is used as a radiation source for the UV region of the spectrum. This is replaced by a tungsten filament lamp when the spectrum is to be determined in the visible region.