Anion resonances and above-threshold dynamics of coenzyme Q0

Bull, J.N.; West, C.W.; Verlet, J.R.R.

Abstract

Temporary radical anions (resonances) of isolated co enzyme Q0 (CQ0) and their associated above-threshold dynamics have been studied using frequency-, angle-, and time-resolved photoelectron imaging (FAT-PI). Experimental energetics and dynamics are supported with ab initio calculations. All results support that CQ0 exhibits similar resonances and energetics compared with the smaller para-benzoquinone subunit, which is commonly considered as a prototype electrophore for larger biological para-quinone species. However, the above-threshold dynamics in CQ0 relative to para-benzoquinone show significantly enhanced prompt detachment compared with internal conversion, particularly around the photoexcitation energy of 3.10 eV. The change in dynamics can be attributed to a combination of an increase in the shape character of the optically-accessible resonance at this energy, a decrease in the autodetachment lifetime due to the higher density of states in the neutral, and a decrease in the probability that the wavepacket formed in the Franck–Condon window can access the local conical intersection in CQ0 over the timescale of autodetachment. Overall, this study serves as a clear example in understanding the trends in spectroscopy and dynamics in relating a simple prototypical para-quinone electrophore to a more complex biochemical species.

Citation

Bull, J., West, C., & Verlet, J. (2015). Anion resonances and above-threshold dynamics of coenzyme Q0. Physical Chemistry Chemical Physics, 17(24), 16125-16135. https://doi.org/10.1039/c5cp02145f

• Journal Article Type: Article
• Acceptance Date: May 19, 2015
• Publication Date: Jun 28, 2015
• Deposit Date: Jun 9, 2015
• Publicly Available Date: May 19, 2016
• Journal: Physical Chemistry Chemical Physics
• Print ISSN: 1463-9076
• Electronic ISSN: 1463-9084
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 17
• Issue: 24
• Pages: 16125-16135
• DOI: https://doi.org/10.1039/c5cp02145f
• Public URL: https://durham-repository.worktribe.com/output/1436452