Mercaptans, naming

At one time thiols were named mercaptans Thus CH3CH2SH was called ethyl mercaptan according to this system This nomenclature was abandoned beginning with the 1965 revision of the lUPAC rules but is still sometimes encountered When one encounters a thiol for the first time especially a low molecular weight thiol its most obvious property is its foul odor Ethanethiol is added to natural gas so that leaks can be detected without special equipment—your nose is so sensitive that it can detect less than one part of ethanethiol m 10 000 000 000 parts of arr The odor of thiols weakens... 

Mercaptan (Section 15 13) An old name for the class of com pounds now known as thiols... 

Physical Properties. Trichloromethanesulfenyl chloride [594-42-3] (perchloromethyl mercaptan, a misnomer but used as the common commercial name), CCl SCl, is a strongly acrid, pale yellow Hquid, boiling at 149°C with some decomposition at atmospheric pressure, 68°C at 6.93 kPa (52... 

Thiols ate still commonly named as mercaptans, although the proper nomenclature is that estabUshed by the International Union of Pure and AppHed Chemists (lUPAC). A listing of the lUPAC name, common name, and stmcture, is shown in Table 1. 

RSH were given the name mercaptans ), displacing the H as with amines ... 

Mercaptans were discovered in 1834 by W. C. Zeise (pp. 930, 1167) who named them from the Latin mercurium captans, catching mercury. 

The gas plant products, namely fuel gas, Cfs, 4, and gasoline, contain sulfur compounds that require treatment. Impurities in the gas plant products are acidic in nature. Examples include hydrogen sulfide (HjS), carbon dioxide (COj), mercaptan (R-SH), phenol (ArOH), and naphthenic acids (R-COOH). Carbonyl and elemental sulfur may also be present in the above streams. These compounds are acidic. 

Another reagent that readily forms fluorescent derivatives with primary amines is o-phthalaldehyde (trade name "Fluoropa"). The reaction proceeds in aqueous solution in the presence of a mercaptan at a pH of 9-11 producing an isoindole. 

As one more common example of liquid fuels present reference may be drawn to liquified petroleum gas (LPG) or bottled gas or refinery gas. This fuel is obtained as a by-product during the cracking of heavy oils or from natural gas. It is dehydrated, desulfurized and traces of odours organic sulfides (mercaptans) are added in order to identify whether a gas leak has occurred. Supply of LPG is carried out under pressure in containers under different trade names. It consists of hydrocarbons of great volatility such that they can occur in the gaseous state under atmospheric pressure, but are readily liquifiable under high pressures. The principal constituents of LPG are n-butane, iso-butane, butylene and propane,... 

COMPOUND NAME CHLORODIFLUOROMETHANE DICHLOROFLUOROMETHANE CHLOROFORM HYDROGEN CYANIDE DIBROMOMETHANE DICHLOROMETHANE FORMALDEHYDE FORMIC ACID METHYL BROMIDE METHYL CHLORIDE METHYL FLUORIDE METHYL IODIDE NITROMETHANE METHANE METHANOL METHYL MERCAPTAN METHYL AMINE METHYL HYDRAZINE METHYL SILANE... 

Semitelechelic HPMA polymers were synthesized by free radical polymerization of HPMA using 2,2 -azobis(isobutyronitrile) (AIBN) as the initiator and alkyl mercaptans as chain transfer agents. Alkyl mercaptans with different functional groups, namely, 2-mercaptoethylamine, 3-mercapto-propionic acid, 3-mercaptopropionic hydrazide, and methyl 3-mercapto-propionate, were used as the chain transfer agents ST HPMA polymers... 

Before 1937 the Chemical Abstracts name was 2-benzimidazole mercaptan. Other names found in the literature are o-phenylenethiourea and 2-thiobenzimi-dazolone. 

Compound Name Iso-Amyl Nitrite Iso-Amyl Nitrite N-Amyl Mercaptan N-Amyl Mercaptan N-Amyltrichlorosilane Ethyl Ether... 

Compound Name Hexachlorocyclopentadiene Tetrachloroethylene Carbon Tetrachloride Perchloromethyl Mercaptan T etrachloroethylene Urea Peroxide Decahydronaphthalene Tetrachloroethylene Hydrogen Peroxide Peracetic Acid... 

Compound Name N-Propyl Mercaptan Isopropyl Mercaptan N-Propyl Mercaptan Isopropyl Mercaptan Glycerine Propionic Acic Propionic Anhydride N-Propyl Alcohol Isopropyl Alcohol Beta-Propiolactone Acetone Acrolein Allyl Alcohol Acrylamide Propylene Propylene Oxide Polypropylene Acrylic Acid Beta-Propiolactone Propionaldehyde Propionic Acid Propionaldehyde Propionic Anhydride Beta-Propiolactone Propionic Anhydride N-Propyl Acetate Isopropyl Acetate N-Propyl Alcohol Isopropyl Alcohol N-Propyl Alcohol Propionaldehyde N-Butyl Alcohol Propylene... 

Compound Name Polypropylene Glycol Tetrahydrofuran Dimethyl Sulfide N-Butyl Mercaptan Thiophosgene Ammonium Thiocyanate Ethyl Mercaptan Methyl Mercaptan Thiophosgene Phosphorus Pentasulfide Thiram Thiram... 

Benzyl mercaptan is another common name for a-toluenethiol. 

An interesting historical sxlel tf on this type of soft-soft rfKeracOon i Uk origin of the name mercaptan. a mercury copturer Hg + + 2RSH — Hg(SR), + 2H4. 

Most natural organic materials which have strong odors, either agreeable or disagreeable, contain either mercaptans or alkyl sulfide. Various mercaptans have been found in crude oil, and the odor contributed by small quantities of these materials led to the name sour crude. 

The traditional name for this group is mercaptans nowadays, the term thiols is more common. They have been identified in more than sixty different foodstuffs. 

Common Name Methanethiol Synonym methyl mercaptan Chemical Name methanethiol CAS Registry No 74-93-1 Molecular Formula CH4S, CH3SH Molecular Weight 48.108 Melting Point (°C) ... 

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