Abstract

In the field of molecular spectroscopy, absorption measurements with electromagnetic radiation covering the wavelengths between 200 nm and 20 μm can be used for analytical applications. By convention, tags such as ultraviolet (UV), visible (VIS), and infrared (IR) were given to special intervals of the spectrum, each yielding different specific information on organic and inorganic substances. The energy for electronic transitions between outer molecular orbitals corresponds to radiation of the first two spectral regions noted, whereas vibrational spectroscopy is connected to the infrared. Here, it can be further distinguished between near- and mid-infrared spectral subregions, which are important for routine analytical work.