An experimental and computational study of the effect of aqueous solution on the multiphoton ionisation photoelectron spectrum of phenol
We revisit the photoelectron spectroscopy of aqueous phenol in an effort to improve our understanding of the impact of inhomogeneous broadening and inelastic scattering on solution-phase photoelectron spectra. Following photoexcitation of the 11ππ* and 11πσ* states of phenol, we observe 11ππ*-D0/D1 ionisation and competing S0-D0/D1 ionisation. Following photoexcitation of the 21ππ* state, we observe the signature of solvated electrons. By comparing the photoelectron spectra of aqueous phenol and gas-phase phenol, we find that inelastic scattering results in peak shifts with similar values to those observed for photoelectron spectra of solvated electrons, highlighting the need for a robust way of deconvoluting the effect of inelastic scattering from liquid-phase photoelectron spectra. We also present a new computational strategy for calculating vertical ionisation energies using a quantum-mechanics/effective fragmentation potential (QM/EFP) approach in which we find that optimising the configurations obtained from molecular dynamics simulations and using the [phenol.(H2O)5]QM[(H2O)n≥250]EFP (B3LYP/aug-cc-pvdz) method gives good agreement with experiment.
- This article is part of the themed collection: Quantum effects in complex systems