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

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 S₁ state because it is situated in the detachment continuum) and E → Z photoisomerization. While autodetachment occurs across the en

SUBMITTER: Ashworth EK 

PROVIDER: S-EPMC9549896 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature