Abstract

The photoinduced electron transfer from zinc tetrakis (4-sulfonatophenyl) porphyrin (ZnTPPS) to duroquinone (DQ) in several micellar solutions was investigated with Fourier transform-electron paramagnetic resonance (FT-EPR). The measurements give information on the formation and decay of free radicals, following pulsed-laser excitation of ZnTPPS, with nanosecond time resolution. It was found that the characteristics and time evolution of the EPR spectra depend strongly on surfactant properties. In particular, long-lived [ZnTPPS 3−… DQ −] spin-correlated radical pairs (lifetime > 1 μs) were observed in solutions of the cationic surfactant cetyltrimethylammonium chloride (CTAC). By contrast, radical pair lifetimes in anionic and neutral micelles are shorter than 100 ns. The experimental data can be rationalized in terms of the Coulombic and hydrophobic interactions that determine the spatial organization and stability of the different species (reactants and products) in the microheterogenous systems.

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 call

Disclaimer: 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.