1220052-19-6Relevant articles and documents
Photodeoxygenation of dibenzothiophene S-oxide derivatives in aqueous media
Korang, James,Grither, Whitney R.,McCulla, Ryan D.
, p. 4466 - 4476 (2010)
The use of atomic oxygen (O(3P)) as potent oxidant In water has suffered from the lack of a facile, efficient source. The photodeoxygenatlon of aromatic sulfoxides to the corresponding sulfides in organic solvents has been suggested to produce O(3P) in low quantum yields. The photolysis of 4,6-dihydroxymethyldibenzothiophene S-oxide and 2,8- dihydroxymethyldibenzothiophene S-oxide in water results in deoxygenation at significantly higher quantum yields than In organic solvents. Depending upon conditions, a variable amount of oxidation of the hydroxymethyl substituent into an aldehyde was observed to accompany deoxygenation. Analysis of the photoproducts Indicated the deoxygenation occurred by at least two different pH-sensitive mechanisms. Under basic conditions, photoinduced electron transfer yielding a hydroxysulfuranyl radical that decomposed by heterolytlc S-O cleavage was thermodynamically feasible. The thermodynamics of photoinduced electron transfer were expected to become increasingly unfavorable as the pH of the solution decreased. Thus, at neutral and acidic pH, an S-O bond scission mechanism was suspected. The observed increase In the photodeoxygenation quantum yields was consistent with charge separation accompanying S-O bond scission. Oxidative cleavage of alkenes In aerobic conditions suggested O(3P) was produced during photolysis In these conditions; however, the formation of discrete O-/HO may occur, particularly at low pH.
