Thiols


I H2S reacts in another way with the olefinic hydrocarbons producing thiols and sulfur compounds (Equation 8.3 and 8.4)  [c.321]

At this point in time, the total sulfur content of crudes was not taken into consideration, since most of them were produced and refined in the United-States and contained less than 1%, and only the gasoline coming from corrosive crudes needed sweetening (elimination of thiols) for them to meet the specifications then in force. Today all crudes containing more than one per cent sulfur are said to be corrosive .  [c.322]

Of the general formula, R - S — H, where R represents an aliphatic or cyclic radical, the thiols —also known as mercaptans— are acidic in behavior owing to their S—H functional group they are corrosive and malodorous. Their concentration in crude oils is very low if not zero, but they are created from other sulfur compounds during refining operations and show up in the light cuts, as illustrated in Table 8.6.  [c.322]

GaAs has been coated with thiols with a view to modifying devices [123]. For these films, S-As bonds are presumed to be present. An ordering of the chains for = 18 has been reported. However, this system has generally been much less investigated than those involving metal substrates.  [c.2625]

Bain C D, Troughton, E B Tao Y T, Evall J and Whitesides G M 1989 Formation of monolayer films by the spontaneous assembly of organic thiols from solution onto gold J. Am. Chem. Soc. Ill 321-35  [c.2635]

Sheen C W, Martensson J, Shi J, Parikh A N and Allara D L A 1992 New class of organized self-assembled monolayers—alkane thiols on GaAs(IOO) J. Am. Chem. Soc. 114 1514-5  [c.2635]

Mercaptans (or thio-alcohols or thiols), the sulphur analogues of the alcohols, were formerly prepared by the interaction of an alkyl halide and sodium hydrosulphide in alcoholic solution  [c.496]

General remarks on the preparation of mercaptans. The above method is of quite general application. If the bromide is inexpensive, the extraction with ether may be omitted, thus rendering the preparation of thiols a comparatively easy and not unduly unpleasant operation. The following mercaptans may be prepared in yields of the same order as those for n-butyl and n-hexyl mercaptans ethyl, b.p. 35-36° n-propyl, b.p. 66-67° isopropyl, b.p. 51-52° isobutyl, b.p. 87-88° n-amyl, b.p. 124-125° n-heptyl, b.p. 175-176° n-octyl, b.p. 198-200° or 98-100°/22 mm.,- n-nonyl, b.p. 220-222° or 98-100°/15 mm. n-decyl, b.p. 96-97°/5 mm. or 114°/13 mm. n-undecyl, b.p. 103-104°/3 mm. n-dodecyl, b.p. lll-112°/3 mm. or 153-155°/24 mm. n-tetradecyl, b.p. 176- 180°/22 mm. benzyl, b.p. 195°.  [c.497]

REACTIONS AND CHARACTERISATION OF MERCAPTANS (THIOLS)  [c.500]

Crystalline Derivatives of Thiols  [c.500]

The melting points of the derivatives of the more commonly occurring thiols are collected in Table 111,168.  [c.501]

Compounds containing one or more —OH or —SH groups, such as water, alcohols, phenols, oximes, hydrogen sulphide and thiols.  [c.914]

Mercaptans and thiophenols (thiols). The thiols are generally liquids with penetrating and disagreeable odours, which persist even at extremely low concentrations in the air. They are soluble in dilute sodium hydroxide solution. Thiols are best characterised as the crystalline 2 4-dinitrophenyl thioethers or as the corresponding sulphones (see Section 111,168).  [c.1078]

Mercaptans (Thiols), Table III, 168.  [c.1083]

Glycosidic thiol groups can be introduced into glycosyl bromides by successive reactions with thiourea and aqueous sodium disulfite (D. Horton, 1963 M. Cemy, 1961, 1963). Such thiols are excellent nucleophiles in weakly basic media and add to electrophilic double bonds, e.g., of maleic esters, to give Michael adducts in high yields. Several chiral amphiphiles have thus been prepared without any need for chromatography (J.-H. Fuhrhop, 1986 A).  [c.269]

HSCH2CH(0H)CH(0H)CH2SH. a useful water soluble reagent for preserving thiols in the reduced state, and for reducing disulphides quantitatively to dithiols.  [c.145]

Al-Obaidi A H R, Rigby S J, Hegarty J N M, Bell S E J and McGarvey J J 1996 Direct formation of silver and gold metal liquid-like films (MELLFS) from thiols and sols without organic solvents SERS and AFM studies ICORS 96 XVth Int. Conf on Raman Spectroscopy ed S A Asher and P B Stein (New York Wiley) pp 590-1  [c.1232]

Self-assembly of long-chain alkanethiols on the Au(l 11) surface has been studied by a number of different teclmiques including AFM, and it has been consistently shown that the molecules fonu a conuuensurate (V3 x a/3)R30° structure. AFM studies can also provide additional infonuation on the mechanical properties of the organic layers [136], which are interesting in that they serve as a model system for lubricants [137]. Above a critical applied load of 280 iiN for the C g thiols, it has been found that the monolayers were disrupted, and that the subsequent image corresponded to that of the Au(l 11) substrate. Flowever, on reducing the load to substantially below the critical value, the surface apparently healed, and the characteristic periodicity of the thiol overlayer returned. The exact way in which this phenomenon occurs is not completely understood [138]. Possibilities mclude displacement of the thiols by the tip, binding of the thiols to the tip, or desorption of the thiols into a liquid phase.  [c.1704]

Nuzzo R G, Zegarski D R and Dubois L H 1987 Fundamental studies of the ohemisorption of organosulfur oompounds on Au(111). Implioations for moleoular self-assembly on gold surfaoes J. Am. Chem. Soc. 109 733 Bain C D, Troughton E B, Tao T, Evall J, Whitesides G M and Nuzzo R G 1989 Formation of monolayer films by the spontaneous assembly of organio thiols from solution onto gold J. Am. Chem. Soc. Ill 321  [c.1722]

Voimer M, Stratmann M and Viefhaus FI 1990 Eleotroohemioal and eleotron speotrosoopio investigations of iron surfaoes modified with thiols Surf. Interf. Anal. 16 278-82  [c.2639]

Bain C D and Whitesides G M 1989 Formation of monolayers by the ooadsorption of thiols on gold—variation in the length of the alkyl ohain J. Am. Chem. Soc. Ill 7164-75  [c.2640]

Bain C D, Evall J and Whitesides G M 1989 Formation of monolayers by the ooadsorption of thiols on gold— variation in the head group, tail group, and solvent J. Am. Chem. Soc. Ill 7155-64  [c.2640]

Of the crystalline derivatives of thiols, those formed with 3 5-dinitro-benzoyl chloride are not very satisfactory since they have, in general lower melting points than those of the corresponding alcohols (compare Section 111,27,7) and do not diflfer widely from ethyl to n-heptyl. The best results are obtained with 2 4-dinitrochlorobenzene.  [c.500]

Alcohols give alkyl chlorides in high yields on treatment with N-chlorosuccinimide and tri-phenylphosphine (D. J. Cram, 1988) or with diethyl diaaenedicarboxylate, triphenylphosphine, and zinc chloride (Mitsunobu type reaction see section 2.6.2). The chloride can be replaced by a thiol group upon treatment with thiourea in DMSO and subsequent basic hydrolysis of the S-alkyl-isothiourea (D.J. Cram, 1988). The preparation of thiols is often plagued by competing disulfide or thioether formation and oxidation of the thiol. The use of lithium tert-butyldimethylsilanethiolate (prepared in situ from hexamethyl.cyclotrisilathiane and Bu Li) removes these problems (G.A. Kraus, 1991). Competing Michael additions are also avoided with this bulky reagent. The resulting silyl thioetbers can be quantitatively hydrolysed with hydrofluoric acid in acetonitrile (R.F. Newton, 1979).  [c.169]


See pages that mention the term Thiols : [c.211]    [c.254]    [c.318]    [c.395]    [c.10]    [c.322]    [c.397]    [c.1684]    [c.2624]    [c.404]    [c.126]    [c.502]    [c.1026]    [c.1035]    [c.122]    [c.126]    [c.120]   
See chapters in:

Encyclopedia of chemical technology volume 24  -> Thiols


Textbook on organic chemistry (1974) -- [ c.496 , c.497 ]

Carey organic chemistry (0) -- [ c.0 ]

Chemistry of Organic Fluorine compounds II (1995) -- [ c.0 ]

Organic chemistry (0) -- [ c.0 ]