Characterization of organic sulfur

Characterization of Organic Sulfur Compounds in Coals and Coal Macerals... 

While the vibrational spectra of thiadiazoles have been well characterized <670379, 68AHC(9)107> the selenation method was used to verify the assignments of a number of organic sulfur compounds, including the parent benzothiadiazole (1) <90JST(218)169>. 

Characterization of Organic Matter in Sulfur-Rich Lacustrine Sediments of Miocene Age (Nordlinger Ries, Southern Germany)... 

Other approaches have been used to characterize the organic sulfur in coal. Programmed temperature reduction (PTR) (9-14) as used by Attar is one such method as is programmed temperature oxidation (PTO) (15-17). Both methods rely on differences in reactivity of the different sulfur species. However, both procedures involve high temperatures and under such conditions transformation between sulfur species is possible. This reaction is highly probable if pyrite or elemental sulfur are present in the sample (18-20). 

Characterization of Organically Bound Sulfur in High-Molecular-Weight, Sedimentary Organic Matter Using Flash Pyrolysis and Raney Ni Desulfurization... 

The bulk mineralogy of the coal, also represented in Table III, is characterized by quartz, calcite, bassanite, kaolinite, and pyrite. Bassanite is probably a low-temperature ashing product of organic sulfur fixation with organically bound calcium (13). Pyrite content appears to increase with depth in the seam relative to calcite and kaolinite. 

Palmer, S.R., Hippo, E.J., Crelling, J.C., and Kruge, M.A. 1992. Characterization and selective removal of organic sulfur from Illinois Basin coals. Coal Preparation, 10 93-106. 

Fluorosulfuric acid [7789-21-17, HSO F, is a colodess-to-light yellow liquid that fumes strongly in moist air and has a sharp odor. It may be regarded as a mixed anhydride of sulfuric and hydrofluoric acids. Fluorosulfuric acid was first identified and characterized in 1892 (1). It is a strong acid and is employed as a catalyst and chemical reagent in a number of chemical processes, such as alkylation (qv), acylation, polymerization, sulfonation, isomerization, and production of organic fluorosulfates (see Friedel-CRAFTSreactions). 

The methods available for synthesis have advanced dramatically in the past half-century. Improvements have been made in selectivity of conditions, versatility of transformations, stereochemical control, and the efficiency of synthetic processes. The range of available reagents has expanded. Many reactions involve compounds of boron, silicon, sulfur, selenium, phosphorus, and tin. Catalysis, particularly by transition metal complexes, has also become a key part of organic synthesis. The mechanisms of catalytic reactions are characterized by catalytic cycles and require an understanding not only of the ultimate bond-forming and bond-breaking steps, but also of the mechanism for regeneration of the active catalytic species and the effect of products, by-products, and other reaction components in the catalytic cycle. 

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