Chromophores of chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins

Anstöter, Cate S.; Dean, Charlie R.; Verlet, Jan R.R.

Abstract

Many photoactive proteins contain chromophores based on para-substituted phenolate anions which are an essential component of their electronic structure. Here, we present a reductionist approach to gain fundamental insight into the evolution of electronic structure as the chromophore increases in complexity from phenolate to that in GFP. Using frequency- and angle-resolved photoelectron spectroscopy, in combination with electronic structure theory, the onset of excited states that are responsible for the characteristic spectroscopic features in biochromophores are determined. A comprehensive, yet intuitive picture of the effect of phenolate functionalisation is developed based on simple Hückel theory. Specifically, the first two bright excited states can be constructed from a linear combination of molecular orbitals localised on the phenolate and para-substituent groups. This essential interaction is first observed for p-vinyl-phenolate. This bottom-up approach offers a readily accessible framework for the design of photoactive chromophores.

Citation

Anstöter, C. S., Dean, C. R., & Verlet, J. R. (2017). Chromophores of chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins. Physical Chemistry Chemical Physics, 19(44), 29772-29779. https://doi.org/10.1039/c7cp05766k

• Journal Article Type: Article
• Acceptance Date: Sep 18, 2017
• Online Publication Date: Sep 18, 2017
• Publication Date: Nov 28, 2017
• Deposit Date: Dec 12, 2017
• Publicly Available Date: Sep 18, 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: 44
• Pages: 29772-29779
• DOI: https://doi.org/10.1039/c7cp05766k
• Public URL: https://durham-repository.worktribe.com/output/1338552