Sulphur Analogues

In contrast to the results in the previous section, the reaction of sodium atoms with hydrogen sulphide (Bennett et al., 1966b) and mer-captans results in the formation of a negative ion in which the electron is associated with only one molecule. This marked difference between compounds of two adjacent elements in the periodic table is readily explainable in terms of the following factors  

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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 ... 

The alkyl sulphides or thioethers, the sulphur analogues of the ethers, are conveniently obtained by boiling alkyl halides with anhydrous sodium sulphide in alcoholic solution, for example ... 

Alkyl sulphides are the sulphur analogues of ethers from which they differ considerably in chemistry. They are unpleasant-smelling oils, insoluble in water but soluble in organic solvents. They tend to be comparatively inert. Mustard gas, CICH2CH2—S—CH2CH2CI, an oily liquid boiling at 216°C with a mustard-like smell, is highly poisonous and a vesicant, and for this reason found use in chemical warfare. 

E. Block, in The Chemistry of Ethers, Crown Ethers, HydroxyI Groups and Their Sulphur Analogues (Ed. S. Patai), Part I, Chap. 13, Wiley, New York, 1980. 

Supplement A The chemistry of double-bonded functional groups (2 parts) Supplement B The chemistry of acid derivatives (2 parts) Supplement C The chemistry of triple-bonded functional groups (2 parts) Supplement D The chemistry of halides, pseudo-halides and azides (2 parts) Supplement E The chemistry of ethers, crown ethers, hydroxyl groups and their sulphur analogues (2 parts)... 

Supplement D The Chemistry of Halides, Pseudo-halides and Azides (two parts) Supplement E The Chemistry of Ethers, Crown Ethers, Hydroxyl Groups and their Sulphur Analogues (two parts)... 

Turning again to primary phosphorofluoridates (R = H), if R is substituted, e.g. in di-(2-chloroethyl) phosphorofluoridates, the toxicity and myotic effect are greatly inferior to those shown by the unsubstituted diethyl phosphorofluoridates. Toxicity is also very low in the aromatic series for example, diphenyl phos-phorofluoridate is non-toxic and devoid of myotic properties. Similar remarks apply to certain sulphur analogues, e.g. diethyl phosphorofluoridodithiolate, POF(SEt)2 (preparation, p. 54). 

In view of the high toxicity of (II), it seemed that the sulphur analogue, dimethylaminosulphonyl fluoride (VI), might be of some interest. We therefore studied the fluorination of dimethylaminosulphonyl chloride. The reaction with potassium fluoride was incomplete, and that with zinc fluoride unsatisfactory, but that with antimony trifluoride using benzene as a solvent proved to be very satisfactory, and an 80 per cent yield of (VI) was obtained. Physiological examination showed that (VI) caused no irritation when small animals were exposed to a concentration of 1 mg./l. for 10 min., and no deaths took place. With the sulphonyl chloride at the same concentration, lacrimation and nasal irritation were caused no deaths were recorded, and all the animals recovered almost immediately on being removed from the chamber. 

Isatin is the inner anhydride (lactam) of a y-amino-a-ketocarboxylic acid, isatinic acid (A), and is converted into a salt of this acid by the action of alkali. The keto-group in position 3 can condense with many other substances, and for this reason isatin is manufactured on a technical scale and converted into valuable indigoid vat dyes. The magnificent thioindigo scarlet, which is obtained from isatin and a sulphur analogue of indoxyl (the so-called hydroxythionaphthene), may be taken as example qq... 

E.s.r. measurements and X-ray studies show that the extra electron in the tricobalt compound occupies an antibonding orbital made up primarily of a combination of two cobalt 3d orbitals localized in the plane of the three cobalt atoms. Replacement of one Co by Fe again leads to a decrease in the metal-metal bond lengths [0.039 A (av)]. The effect is therefore not so marked as with the sulphur analogues and the effect of replacing sulphur by selenium in [C03-(CO)gS] is to decrease the metal-metal distances by 0.021 The relevant data for the three compounds are given below ... 

The chiral base 360 turns out not to be the best choice for enantioselective lithiation of the sulphur analogue 437 (Scheme 177) the bis-lithium amide 438 in the presence of LiCl at — 100°C gives better yields and enantioselectivity The base 438 often turns out to be a good choice as an alternative to 360 for reactions that fail to give good enantioselectivity. ... 

Vogtle, F. Weber, E. In The Chemistry of the Functional Groups. Supplement E. The Chemistiy of Ethers, Crown Ethers, Hydroxyl Groups, and Their Sulphur Analogues, Part 1 Patai, S., Ed. Wiley Chichester, 1980 pp. 59-156 Vogtle, F. Sieger, H. Muller, W. M. Top. Curr. Chem. 1981, 98, 107. 

As the chelate selenide complexes reacted with -toluidine mainly by displacing the coordinated olefinic group from the metal, Goodall assumed that they were more stable than the sulphur analogues. 

Thiourea (SC(NH2)2), the sulphur analogue of urea, is the most commonly used sulphur precursor. There are a number of possible decomposition routes for thiourea in aqueons solntion (it is invariably nsed in alkaline solntions). Probably the most important is... 

Thiols, general formula RSH, are the sulphur analogues of alcohols. The functional group of a thiol is —SH. The simplest members of this class are methanethiol (CH3SH), ethanethiol (C2H5SH) and propanethiol (C3HVSH). 

According to this view the intermediate sulphur atoms are probably arranged in a similar manner in the polythionic acids and the hydrogen polysulphides, and tetrathionic acid may be considered as a sulphur analogue to perdisulphuric acid.2... 

Carbon Monosulphide, CS.—This sulphur analogue of carbon monoxide is described as resulting8 on passing carbon disulphide vapour over spongy platinum, pumice stone or red-hot charcoal. It is also formed by the action of the silent electric discharge 7 on carbon disulphide or on a mixture of the latter with either hydrogen or carbon monoxide, thus ... 

The affinity of selenium for oxygen is less than that of sulphur. The dioxide, SeQ2, is well defined. The trioxide, Se03, is much less stable than its sulphur analogue, and until recently all attempts to isolate it have been unsuccessful (see p. 331). Selenium sesquioxide, Se203, has not been definitely isolated.1 An oxide of composition Se304 has been described,2 but its existence needs confirmation. The existence of a lower oxide, SeO, postulated to explain the characteristic odour of selenium when vaporised in air, is improbable.3... 

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