Sulfur compounds Raman spectra

The differences in selection rules between Raman and infrared spectroscopy define the ideal situations for each. Raman spectroscopy performs well on compounds with double or triple bonds, different isomers, sulfur-containing and symmetric species. The Raman spectrum of water is extremely weak so direct measurements of aqueous systems are easy to do. Polar solvents also typically have weak Raman spectra, enabling direct measurement of samples in these solvents. Some rough rules to predict the relative strength of Raman intensity from certain vibrations are [7] ... 

When Sio was prepared from Se according to several slightly different procedures (see above) the formation of a new sulfur allotrope was observed several times. This allotrope forms intense orange-yellow, opaque, hexagonal plate-like crystals [34, 35]. An X-ray study on single crystals of this allotrope proved the assumption of a molecular addition compound Se-Sm as had been suggested before by evaluation of the Raman spectrum [34, 35],... 

Sulfur dicyanide is a white crystalline solid that sublimes under vacuum at 25°. It is hygroscopic but can be stored under anhydrous conditions at 0° for long periods. It is not maricedly stable at 25°. On standing at this temperature in the absence of air, it slowly forms a yellow material of unknown composition. It is moderately soluble in water, very soluble in ether, and soluble in warm carbon disulfide. The Raman spectrum of S(CN)2 suggests a bent structure. The IR spectrum of the compound in a Nujol mull has absorption bands at 2190 (m) (C=N) and 1090 (w) (S—C) cm . ... 

Other Sulfur and Selenium Compounds. - The high-pressure Raman spectrum of D2S gave evidence for dissociation to sulfur at pressures above 27 GPa at room temperature. A normal coordinate analysis for crystalline H2S and D2S gave good agreement with experimental data. ... 

Infrared absorption data for l-methyl-2-mercaptoimidazole indicate that this compound exists entirely in the thione form in chloroform solution (Ettlinger, 1950). Studies by Lawson and Morley (1956) on the ultraviolet absorption characteristics of 2-mercaptoimidazoles suggest that the absorption peak in the region of 260 m i, which is common to this class of compounds, is due to the presence of the thione form elimination of this structural form by alkylation of the sulfur atom changes the position and intensity of the absorption peak. It seems likely that ergothioneine exists chiefly as the thione, which is in equilibrium with the thiol form. A study of the Raman or infrared spectrum of ergothioneine would be valuable in this connection. It is known that the sulfur does not exhibit some of the... 

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