Abstract
Picosecond transient absorption spectroscopy was utilized to study the recombination dynamics of triplet sulfur radical pairs. A disulfide, bis(p-benzoylphenyl) disulfide (BpSSBp), was designed to selectively produce triplet thiyl radical pairs by means of internal triplet energy transfer. Thus, irradiation of bis(p-benzoylphenyl) disulfide (BpSSBp) in Tetralin (355 nm, 17 ps) followed by instantaneous singlet - triplet interconversion of the photoexcited benzoyl group leads to rapid intramolecular energy transfer and S - S bond scission. Greater than 50% of the photochemically generated (presumably triplet) radical pairs were found to recombine in competition with cage escape. Benzoyl substitution of phenyl disulfide is expected to cause intersystem crossing (ISC) from the singlet excited state to the triplet state to occur before singlet S - S bond scission can occur. However, benzoyl substitution is not expected to perturb the orbital degeneracy on the thiyl radical that has been suggested to be responsible for the strong spin-orbit coupling mechanism and fast ISC of sulfur-centered radical pairs in micellar solutions. Thus, this study provides the first direct observation of fast ISC (> 100 ps) of sulfur-centered radical pairs in organic solvents. 23 refs., 2 figs.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
