683278-62-8Relevant articles and documents
Mechanism and Kinetics of Photoisomerization of a Cyclic Disulfide, trans-4,5-Dihydroxy-1,2-dithiacyclohexane
Barron, Lorena B.,Waterman, Kenneth C.,Filipiak, Piotr,Hug, Gordon L.,Nauser, Thomas,Schoeneich, Christian
, p. 2247 - 2255 (2007/10/03)
The photolysis of trans-4,5-dihydroxy-1,2-ditniacyclohexane in aqueous and CH2Cl2 solution yields two isomers of 2,3-dihydroxy-l- mercaptotetrahydrothiophene, characterized by 1H and 13C NMR and negative ion electrospray mass spectrometry. Product formation in water is independent of the presence of oxygen and the concentration of trans-4,5-dihydroxy-1,2-dithia-cyclohexane and involves intramolecular 1,5-H-transfer, followed by cyclization through thiophilic or nucleophilic addition, or 1,2-H- transfer, followed by cyclization through the recombination of a sulfur- and a carbon-centered radical. In contrast, the quantum yields for reaction in CH2Cl2 solutions are dependent on both oxygen concentration and on the concentration of trans-4,5-dihydroxy-1,2- dithiacyclohexane. The latter results are consistent with an intermolecular H-transfer between an initial dithiyl diradical and trans-4,5-dihydroxy-1,2- dithia-cyclohexane. Time-resolved laser flash photolysis studies indicate rapid product formation on the submicrosecond time scale and support the intermediacy of α-mercaptoalkyl radicals.
