Broadband spectral probing revealing ultrafast photochemical branching after ultraviolet excitation of the aqueous phenolate anion

摘要: Electron photodetachment from the aromatic anion phenolate excited into π−π* singlet state (S1) in aqueous solution is studied with ultrafast transient absorption spectroscopy a time resolution of better than 50 fs. Broad-band spectra 300 to 690 nm are recorded. The bands assigned solvated electron, phenoxyl radical, and S1 state, confirmation these assignments achieved using both KNO3 as electron quencher time-resolved fluorescence measure dynamics. lifetime found be short (∼20 ps) water, but fast decay only part due ejection channel S1. Using global target analysis, two channels identified, we propose that vibrationally hot relaxed direct precursors for electron. Therefore, just compete picosecond s...