Carbon disulphide, photolysis

IJOC4570). Photolysis or thermolysis of naphtho[ c]thiete 20 and naph-tho[carbon disulphide, also occurs by a free-radical mechanism which leads to naphtho[other products of these conversions [79JA7684 81JCS(P1)413]. 

Reaction of S( D2) and S( Pi) atoms (generated by photolysis of COS in the gas phase) with acetylene yields carbon disulphide, benzene, and thiophene. With hexafluorobut-2-yne, however, only perfluorotetramethylthiophene is formed, although on prolonged irradiation, more complex products such as thiophenes (161) and (162) can be isolated. Highly reactive thiirenes and thio-formylmethylenes have been proposed as intermediates. 

Synthesis of Meso-ionic Thiazoles.—The anhydro-5-hydroxythiazolium hydroxide (43 R = SMe, R = COCF3) is obtained from the reaction between sarcosine, carbon disulphide, methyl iodide, and potassium hydroxide, followed by treatment of the intermediate MeSC(S)NMeCH2C02H (A) with trifluoroacetic anhydride. Methanolysis of (43) gives the methyl ester of the intermediate (A), whilst photolysis yields F3C0CH(C02Me)NMeCS2Me. 

The photolysis of the poly(methylene polysulphides) yields about 100 times more carbon disulphide than the poly(ethylene polysulphides) [1047]. 

Chemical Properties.—Photolytic Reactions. The mechanism of the photolysis of 1,2,3-thiadiazole involves the intermediate formation of the thioketen (20) and thiiren (19), which decompose to the observed photoproducts, carbon disulphide, and ethynethiol (18), respectively. The growth rates of bands of comparable intensity in the i.r. spectra of (20) and (18) indicate that these species are increasing at a similar rate. The photolysis of 4- and 5-deuteriothiadiazole was similarly studied. ... 

Carbon-sulphur bond homolysis has been shown to be, in addition to sulphur-sulphur bond homolysis, a primary process in the photolysis of disulphides in solution. Sulphur-sulphur bond homolysis is, however, responsible for the establishment of an equilibrium between various alkyl disulphides on irradiation." Other liquid-phase studies of the photodecomposition of acyclic alkyl disulphides have been reported," -and the quantum yield for the formation of methyl ethyl disulphide from methyl disulphide and ethyl disulphide has been determined. ... 

Photolysis of allyl pent-4-enyl sulphides such as (9) gave mixtures of five- and six-membered sulphur heterocycles via unsaturated thiyl radicals. Oxidative decarboxylation of the disulphide (10), and intramolecular trapping of the intermediate carbon radical to give the thiolan (11), indicated a biochemical pathway for the formation of the C(2)—S bond of penicillins. ... 

Thermolysis of diazotetrazole (718) gives rise to atomic carbon in the presence of propane, a mixture of but-l-ene, cis- and rrans-but-2-ene, isobutene, and methylcyclopropane, as well as propene, methane, and acetylene, is obtained/ Tris(methylimino)methane (720), the first nitrogen analogue of tri-methylenemethane, is generated by low-temperature photolysis of the tetrazoline l-Methoxy-5-phenyltetrazole (721) rearranges to the tetrazole 7V-oxide (722) at 200 The main product of the reaction of diazomethane with the tetrazolyl disulphide (723) is the rearranged thione (724)/ Irradiation of the... 

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