Bad breathBad breath, also known as halitosis, is a symptom in which a noticeably unpleasant breath odour is present. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder. The concerns of bad breath may be divided into genuine and non-genuine cases. Of those who have genuine bad breath, about 85% of cases come from inside the mouth. The remaining cases are believed to be due to disorders in the nose, sinuses, throat, lungs, esophagus, or stomach.
SulfonamideIn organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. Because of the rigidity of the functional group, sulfonamides are typically crystalline; for this reason, the formation of a sulfonamide is a classic method to convert an amine into a crystalline derivative which can be identified by its melting point.
Polymer stabilizersPolymer stabilizers (British: polymer stabilisers) are chemical additives which may be added to polymeric materials, such as plastics and rubbers, to inhibit or retard their degradation. Common polymer degradation processes include oxidation, UV-damage, thermal degradation, ozonolysis, combinations thereof such as photo-oxidation, as well as reactions with catalyst residues, dyes, or impurities. All of these degrade the polymer at a chemical level, via chain scission, uncontrolled recombination and cross-linking, which adversely affects many key properties such as strength, malleability, appearance and colour.
ThialIn organic chemistry, a thial or thioaldehyde is a functional group which is similar to an aldehyde, , in which a sulfur (S) atom replaces the oxygen (O) atom of the aldehyde (R represents an alkyl or aryl group). Thioaldehydes are even more reactive than thioketones. Unhindered thioaldehydes are generally too reactive to be isolated — for example, thioformaldehyde, , condenses to the cyclic trimer 1,3,5-trithiane. Thioacrolein, , formed by decomposition of allicin from garlic, undergoes a self Diels-Alder reaction giving isomeric vinyldithiins.
TetrahydrothiopheneTetrahydrothiophene is an organosulfur compound with the formula (CH2)4S. The molecule consists of a five-membered saturated ring with four methylene groups and a sulfur atom. It is the saturated analog of thiophene. It is a volatile, colorless liquid with an intensely unpleasant odor. It is also known as thiophane, thiolane, or THT. Tetrahydrothiophene is prepared by the reaction of tetrahydrofuran with hydrogen sulfide. This vapor-phase reaction is catalyzed by alumina and other heterogenous acid catalysts.
Sulfenic acidIn chemistry, a sulfenic acid is an organosulfur compound and oxoacid with the general formula . It is the first member of the family of organosulfur oxoacids, which also include sulfinic acids () and sulfonic acids (), respectively. The base member of the sulfenic acid series with R = H is hydrogen thioperoxide. In contrast to sulfinic and sulfonic acids, simple sulfenic acids, such as methanesulfenic acid, CH3SOH, are highly reactive and cannot be isolated in solution.
Methanesulfonic acidMethanesulfonic acid (MsOH) or methanesulphonic acid (in British English) is an organosulfuric, colorless liquid with the molecular formula and structure . It is the simplest of the alkylsulfonic acids (). Salts and esters of methanesulfonic acid are known as mesylates (or methanesulfonates, as in ethyl methanesulfonate). It is hygroscopic in its concentrated form. Methanesulfonic acid can dissolve a wide range of metal salts, many of them in significantly higher concentrations than in hydrochloric acid (HCl) or sulfuric acid ().
Sulfonyl groupIn organosulfur chemistry, a sulfonyl group can refer either to a functional group found primarily in sulfones, or to a substituent obtained from a sulfonic acid by the removal of the hydroxyl group, similarly to acyl groups. Sulfonyl groups can be written as having the general formula , where there are two double bonds between the sulfur and oxygen. Sulfonyl groups can be reduced to the sulfide with DIBALH. Lithium aluminium hydride () reduces some but not all sulfones to sulfides.
