Unveiling the excited state energy transfer pathways in peridinin-chlorophyll a-protein by ultrafast multi-pulse transient absorption spectroscopy

Summary, in English

Time-resolved multi-pulse methods were applied to investigate the excited state dynamics, the interstate couplings, and the excited state energy transfer pathways between the light-harvesting pigments in peridinin-chlorophyll a-protein (PCP). The utilized pump-dump-probe techniques are based on perturbation of the regular PCP energy transfer pathway. The PCP complexes were initially excited with an ultrashort pulse, resonant to the S₀ → S₂ transition of the carotenoid peridinin. A portion of the peridinin-based emissive intramolecular charge transfer (ICT) state was then depopulated by applying an ultrashort NIR pulse that perturbed the interaction between S₁ and ICT states and the energy flow from the carotenoids to the chlorophylls. The presented data indicate that the peridinin S₁ and ICT states are spectrally distinct and coexist in an excited state equilibrium in the PCP complex. Moreover, numeric analysis of the experimental data asserts ICT → Chl-a as the main energy transfer pathway in the photoexcited PCP systems.

• Author: Kipras Redeckas; Vladislava Voiciuk; Donatas Zigmantas; Roger G. Hiller; Mikas Vengris
• Department/s: Chemical Physics
• Publishing year: 2017-04-01
• Language: English
• Pages: 297-307
• Publication/Series: Biochimica et Biophysica Acta - Bioenergetics
• Volume: 1858
• Issue: 4
• Links: http://dx.doi.org/10.1016/j.bbabio.2017.01.014
• Document type: Journal article
• Publisher: Elsevier
• Topic: Biophysics; Physical Chemistry (including Surface- and Colloid Chemistry); Physical Sciences
• Keywords: Excitation energy transfer; Excited state equilibrium; Intramolecular charge transfer; Peridinin-chlorophyll a-protein; Pump-dump-probe; Pump-probe
• Status: Published
• ISBN/ISSN/Other: ISSN: 0005-2728