Oxyanions of sulfur

DeWeerd, K. A., Concannon, F. Suflita, J.M. (1991). Relationship between hydrogen consumption, dehalogenation, and the reduction of sulfur oxyanions by D. tiedjei. Applied and Environmental Microbiology, 57, 1929-34. 

The topics covered in this book include the above kinds of information for oxyanions of the elements which form discrete anions carbon, sulfur, nitrogen, and the halogens including ... 

What we found is that all metal ions catalyze P—O fission. Selective P—O fission by amines was increased from 80% to 100% in the presence of Mg2+ ion, which also enhanced the rate. Exclusive P—O fission also occurred in the attack by the oxyanion of PCA in the presence of Zn2+ ion. A plausible rationale is that such a path, which involves metal ion assistance in a pentacovalent intermediate as illustrated in Figure 12a, is energetically much more favorable than that of Sn2 displacement on sulfur. Conversely, if an enzyme that catalyzes the reaction of phosphosulfate is metal ion dependent, the reaction probably involves P—O fission, as suggested by Roy (4). 

The structure of NaHSOs, sodium bisulfite, is rather curious. It is an oxyanion of a sulfur(IV) compound with a lone pair of electrons—the HOMO—on the sulfur atom, but the charge is formally on the more electronegative oxygen As a third row element (third row of the periodic table, that is) sulfur can have more that )ust eight electrons—it s all right to have four or six bonds to S or P, unlike, say, B OrN. 

Included in Table I are molybdenum enzymes that are as yet unclassified due to their partial characterization (46—49, 58). These enzymes includes polysulfide reductase that accomplish sulfur reduction to sulfide (46), underlining its role in the global sulfur cycling. Chlorate and selenate reductase are examples of relatively rare enzymes using simple oxyanions of third-row elements as substrates (47 19, 58). 

A wide range of oxyacids is possible with more than one sulfur atom. Although the acids are not always very stable, the oxyanions are often more easily prepared. Many of these are likely intermediates in the oxidation of aqueous sulfites and occur at low concentration in water droplets in the atmosphere. Higher concentrations of sulfur oxyanions such as 8406, SsO , and S Ol can be found in mineralized acid-sulfate waters of volcanic crater lakes (e.g., Sriwana et al, 2000). 

Townsend, G.T. and J.M. Suflita. 1997. Influence of sulfur oxyanions on reductive dehalogenation activities in Desulfomonile tiedjei. Appl. Environ. Microbiol. 63 3594-3599. 

Carbon is the basis of organic chemistry there are more compounds of carbon than of any other element except hydrogen and possibly fluorine. However, most of the chemistry of carbon is the province of organic chemistry and thus not covered in this encyclopedia. The inorganic chemistry of carbon discussed in this article, which is an update of an excellent article written previously by professor R. Bruce King (University of Georgia, Athens), includes the allotropic forms of elemental carbon, simple molecular carbon halides and oxides, carbon oxyacids and oxyanions, carbon-sulfur derivatives, simple cyano derivatives, and carbon-based molecular ladders. 

The nucleophilicity of sulfur anions, for example, the hydrosulfide anion (HS ), the hydrogen disulfide anion (HS2 ), and thiolate anions (RS ), appears to be significantly superior to the corresponding oxygen derivatives (i.e., the hydroxide anion [OH ], the hydrogen peroxide anion [HO2 ], and alkoxide anions [RO ]) under similar conditions, and both the polarizability of sulfur and the extent of solvation of the respective oxyanions (but not the thioanions) have been implicated. 

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