Answer to Question #117306 in Physical Chemistry for Ayesha

Question

Wavelength dependent photochemistry of phenol.

Answer 1

The excitation wavelength dependence of the photochemistry of phenol, p-cresol, and tyrosine in neutral and acidic aqueous solution was examined using Fourier Transform Electron Paramagnetic Resonance (FT-EPR). Photoexcitation gives rise to formation of phenoxyl, p-cresyl, or tyrosyl radicals (PhO•), hydrated electrons ($e_{aq}^-$ ), and hydrogen atoms (H•). From Chemically Induced Dynamic Electron Polarization (CIDEP) effects and the effect of addition of N2O on the spectra it can be deduced that the mechanism of hydrogen atom formation depends on the wavelength of excitation