Panoramic portrait of primary molecular events preceding excited state proton transfer in water.

ABSTRACT: Photochemistry powers numerous processes from luminescence and human vision, to light harvesting. However, the elucidation of multidimensional photochemical reaction coordinates on molecular timescales remains challenging. We developed wavelength-tunable femtosecond stimulated Raman spectroscopy to simultaneously achieve pre-resonance enhancement for transient reactant and product species of the widely used photoacid pyranine undergoing excited-state proton transfer (ESPT) reaction in solution. In the low-frequency region, the 280 cm^-1 ring deformation mode following 400 nm photoexcitation exhibits pronounced intensity oscillations on the sub-picosecond timescale due to anharmonic vibrational coupling to the 180 cm^-1 hydrogen-bond stretching mode only in ESPT-capable

SUBMITTER: Liu W 

PROVIDER: S-EPMC6021748 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature