Raman spectrocopy

Resonance Raman spectrocopy can give the spectrum of the objective species only, even if the sample to be studied has a complex composition by selecting the excitation wavelength of laser light. Therefore, determination of the structure of adsorbed species from resonance Raman spectra can be more straightforward than in the assignment of IR spectra complicated with the presence of several adsorbed species and interfered with the absorption of clay mineral itself. 

Vibrational spectroscopy is designed to study the structure of matter by analyzing the absorption, emission (e.g., Raman spectrocopy), and reflection spectra that are produced by quantum transitions between the vibration energy levels of molecules. The main methods employed in vibrational spectroscopy are IR spectroscopy and Raman spectroscopy. IR spectra are spectra of absorption and in their interpretation, one makes nse of the concept of absorption bands. The presence of fluorescence and thermal emission makes obstacles for Raman measurements. Raman and IR spectroscopy, being complementary techniqnes, provide valnable insights into phase composition and surface termination of ND (see, e.g.. Ref. 38). 

See also Cosmochemical Applications Using Mass Spectrometry Microwave and Radiowave Spectroscopy, Applications Rotationai Spectroscopy, Theory Solid State NMR, Rotationai Resonance Vibrationai, Rotational and Raman Spectrocopy, Historical Perspective. 

In light of recent advances in solid state Hg NMR, Raman, IR, EXAFS, and electronic spectrocopies summarized here, Hg(II) complexes can no longer be considered as spectroscopically silent. A formidable barrier to establishing reliable spectroscopic correlations with the coordination environment still exists because of the small number of well characterized small molecule complexes. Solution Hg NMR, vibrational, and electronic spectroscopies can distinguish complexes with a coordination number of 2 from those with CN = 3 or 4. None of these techniques can readily distinguish between three and four coordination however. Recent advances in solid-state Hg NMR spectroscopy unequivocally demonstrate that Hg-SR complexes with a primary coordination number of three or four can be readily distinguished. 

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