thiyl radical

We have tried to demonstrate that the thiyl radicals are also chain carriers.

The results of the study did not indicate a rapid reaction between thiyl radical and organic nitrate.

No thiyl radicals are observed following radiolysis, or upon photo-bleaching the new species.

Thiyl radicals are also intermediates in the vulcanization process.

Key words: nitrate, photolysis, thiyl radical, nitrogen dioxide, nitric oxide.

Key words: glutathione, thiyl radical, a-C-radical, hydrogen transfer.

Rate constants are the same whether the thiyl radicals are generated from thiols or their corresponding disulphides.

In biology thiyl radicals are responsible for the formation of the deoxyribonucleic acids, building blocks for DNA.

Keywords: isotope effects, muonium atoms, muonium bonding, thiyl radicals, micelles.

Thiyl radicals (sulfur-centred) can transform to carbon-centred radicals via hydrogen atom exchange equilibria.

Hypochlorite-induced oxidation of thiols: formation of thiyl radicals and the role of sulfenyl chlorides as intermediates.

The Cys418 thiyl radical adds covalently to C2 (second carbon atom) of pyruvate, generating an acetyl-enzyme intermediate (which now contains the radical).

The thiyl radical propagates with the alkene to form a carbon centered radical, the previous double bond now allows free-rotation around the sigma bond.

The e.p.r. spectrum of thiyl radicals is obtained when dilute solutions of aliphatic mercaptans are photolyzed in a xenon matrix at 77 °K.

In this paper, we present several lines of evidence that strongly suggest that molecular oxygen is not essential for DNA cleavage and that thiyl radicals may also be involved.

The e.s.r. absorption due to the solvent species disappears when the matrix is warmed a few degrees above 77 °K but thiyl radicals are stable up to the melting point of the glass.

To examine the involvement of thiyl radicals in such a process, the photochemical generation of benzenethiyl radical from thiol and disulfide precursors was studied in the presence of isopropyl nitrate.

•) which dominate the initial epr spectrum at 77 K. Thiyl radicals (RS •) are produced in significant amounts only after the sulfide glasses have been warmed slightly to allow the cage reaction, to occur.

In all three types of system examined in this investigation all thiyl radicals can be accounted for stoichiometrically on the basis of exchange and combination reactions alone, indicating negligible disproportionation of these species in condensed phase.

The agreement between the energies from theory in the gas phase and experiment in solution suggests that the free energies of solvation of reactant thiyl radical, transition structures for H abstraction, and the product a-C-centred radical, are very similar.

These observations suggest that reaction between thiyl radicals and nitrates leading to NO release is a viable pathway, but it is subservient to other competing reactions, such as photolysis, in the case of IPN, and reaction with thiolate, in the case of the novel nitrate.