![]() In particular, in the Born-Oppenheimer and harmonic approximations, i.e. The energies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms, and the associated vibronic coupling. the frequency of the absorbed radiation matches the frequency of the bond or group that vibrates. These absorptions are resonant frequencies, i.e. Infrared spectroscopy exploits the fact that molecules absorb specific frequencies that are characteristic of their structure. The names and classifications of these subregions are conventions, and are only loosely based on the relative molecular or electromagnetic properties. The far-infrared, approximately 400-10 cm -1 (25-1000 μm), lying adjacent to the microwave region, has low energy and may be used for rotational spectroscopy. The mid-infrared, approximately 4000-400 cm -1 (2.5-25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The higher energy near-IR, approximately 14000-4000 cm -1 (0.8-2.5 μm wavelength) can excite overtone or harmonic vibrations. The infrared portion of the electromagnetic spectrum is usually divided into three regions the near-, mid- and far- infrared, named for their relation to the visible spectrum. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer. As with all spectroscopic techniques, it can be used to identify and study chemicals. It covers a range of techniques, mostly based on absorption spectroscopy. Infrared spectroscopy (IR spectroscopy) is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. IMM Instrument Pages IMM Instrument Pages. ![]() Optical Spectroscopy Optical Spectroscopy.Analysis & Separation Analysis & Separation. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |