English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Chemical reactions proceed on the complex potential energy surface (PES), which consists of a vast degree of freedom of nuclear coordinates for polyatomic molecular systems. For unraveling (and manipulating) the reaction coordinate and molecular mechanisms that underlie the reaction, it is desirable to map out the PES, which has been a long-lasting central subject in both experimental and theoretical chemistries. In this quest, understanding of the vibrational coupling between normal mode coordinates is essential, since it actually characterizes the complex shape of the PES. Here, we report fifth-order time-domain Raman spectroscopy of a bacterial photoreceptor, photoactive yellow protein (PYP), with the aim to visualize vibrational coupling in its reactive excited state. After the ultrashort actinic pump pulse prepared the vibrational coherence as well as population in the excited state, the evolving vibrational structure was tracked by time-resolved impulsive stimulated Raman spectroscopy using sub-7-fs pulses (Fig. 1A) [1,2]. The obtained fifth-order timedomain Raman data were translated to a two-dimensional (2D) frequency-frequency correlation map (Fig. 1B), which visualizes the correlation between lowand high-frequency vibrational modes of the excited state. The 2D map of PYP reveals a cross peak, indicating the coupling between the phenolic C-O stretch mode of the PYP chromophore and the low-frequency modes (~160 cm-1) that are assignable to the intermolecular motions involving the surrounding hydrogen-bonded amino acids. The unveiled coupling suggests the importance of the role of the low-frequency vibrational motion in the primary photoreaction process of PYP, highlighting the unique capability of this new spectroscopic approach for studying ultrafast reaction dynamics [3].

Fifth-order impulsive stimulated Raman spectroscopy for visualizing vibrational coupling in reactive excited states