Dynamics of π*-resonances in anionic clusters of para-toluquinone

Bull, James N.; Verlet, Jan R.R.

Abstract

Frequency-resolved photoelectron spectroscopy applied to mass-selected cluster anions is an insightful approach to characterise the dynamics of π*-resonances with microsolvation. Here, the technique is demonstrated with monomer, dimer and trimer radical anions of para-toluquinone (pTQ) over a ∼1 eV excitation window above the detachment threshold. The pTQ− spectra show similar resonances and dynamics to para-benzoquinone, a prototype electrophore. The dimer, (pTQ)2−, has a π-stacked geometry and shows a competition between photodissociation and prompt autodetachment. The trimer, (pTQ)3−, also has a π-stacked cluster geometry and shows vibrational autodetachment from a non-valence state up to ∼0.7 eV above-threshold, outcompeting dissociation. At higher photoexcitation energies, (pTQ)3− shows monomer-like dynamics, blue-shifted in photoexcitation energy by the cluster cohesion energy. Overall, the study highlights the variety of non-adiabatic dynamics available to π*-resonances and the profound changes that occur through clusterization with one and two monomers.

Citation

Bull, J. N., & Verlet, J. R. (2017). Dynamics of π*-resonances in anionic clusters of para-toluquinone. Physical Chemistry Chemical Physics, 19(39), 26589-26595. https://doi.org/10.1039/c7cp03628k

• Journal Article Type: Article
• Acceptance Date: Sep 17, 2017
• Online Publication Date: Sep 18, 2017
• Publication Date: Oct 21, 2017
• Deposit Date: Dec 12, 2017
• Publicly Available Date: Sep 17, 2018
• Journal: Physical Chemistry Chemical Physics
• Print ISSN: 1463-9076
• Electronic ISSN: 1463-9084
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 19
• Issue: 39
• Pages: 26589-26595
• DOI: https://doi.org/10.1039/c7cp03628k
• Public URL: https://durham-repository.worktribe.com/output/1343047