18995-30-7Relevant articles and documents
Photo-induced proton-coupled electron transfer reactions of acridine orange: Comprehensive spectral and kinetics analysis
Eisenhart, Thomas T.,Dempsey, Jillian L.
supporting information, p. 12221 - 12224 (2014/11/08)
The triplet excited state of acridine orange (3*AO) undergoes a proton-coupled electron transfer (PCET) reaction with tri-tert-butylphenol (ttbPhOH) in acetonitrile. Each of the reaction components possesses a spectroscopic signature, providing a rare opportunity to monitor the individual proton transfer, electron transfer, and H ?-transfer components in parallel via transient absorption spectroscopy. This enhanced optical tracking, along with excited-state thermochemical analysis, facilitates assignment of the mechanism of excited-state PCET reactivity. 3*AO is quenched via concerted proton-electron transfer (CPET) from ttbPhOH to form acridine radical (AOH?) and ttbPhO? (kCPET = 3.7 × 108 M-1 s-1, KIE = 1.3). Subsequently, AOH? reduces the phenoxyl radical (kET = 5.5 × 109 M-1 s-1), forming AOH + and ttbPhO-, followed by proton transfer (kPT = 1.0 × 109 M-1 s-1) to regenerate the starting reactants.