Journal article

Excited-State Barrier Controls E → Z Photoisomerization in p-Hydroxycinnamate Biochromophores

EK Ashworth, NJA Coughlan, WS Hopkins, EJ Bieske, JN Bull

Journal of Physical Chemistry Letters | AMER CHEMICAL SOC | Published : 2022

Abstract

Molecules based on the deprotonated p-hydroxycinnamate moiety are widespread in nature, including serving as UV filters in the leaves of plants and as the biochromophore in photoactive yellow protein. The photophysical behavior of these chromophores is centered around a rapid E → Z photoisomerization by passage through a conical intersection seam. Here, we use photoisomerization and photodissociation action spectroscopies with deprotonated 4-hydroxybenzal acetone (pCK-) to characterize a wavelength-dependent bifurcation between electron autodetachment (spontaneous ejection of an electron from the S1state because it is situated in the detachment continuum) and E → Z photoisomerization. While ..

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University of Melbourne Researchers

Grants

Awarded by Natural Sciences and Engineering Research Council of Canada


Funding Acknowledgements

This research was funded through a University of East Anglia start-up allowance (to J.N.B.), the Australian Research Council Discovery Project scheme (DP150101427 and DP160100474 to E.J.B.), and a NSERC Discovery Grant (RGPIN-201704217 to W.H.S.). E.K.A. acknowledges a University of East Anglia doctoral studentship. N.J.A.C. acknowledges a VanierBanting Postdoctoral Fellowship from NSERC. Dr. Palas Roy is thanked for training on the fluorescence upconversion experiment. Electronic structure calculations were performed on the High Performance Computing Cluster supported by the Research and Specialist Computing Support service at the University of East Anglia.