Unveiling the excited state energy transfer pathways in peridinin-chlorophyll a-protein by ultrafast multi-pulse transient absorption spectroscopy.
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→S2transition 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 S1and ICT states and the energy flow from the carotenoids to the chlorophylls. The presented data indicate that the peridinin S1and 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.
Department of Quantum Electronics, Faculty of Physics, Vilnius University, Saulėtekio av. 10, LT-10223 Vilnius, Lithuania. Electronic address: kipras.redeckas@ff.vu.lt.
Kipras
K
Redeckas
Department of Quantum Electronics, Faculty of Physics, Vilnius University, Saulėtekio av. 10, LT-10223 Vilnius, Lithuania.
Vladislava
V
Voiciuk
Department of Chemical Physics, Lund University, P.O. Box 124, 22100 Lund, Sweden.
Donatas
D
Zigmantas
Department of Biological Sciences, Macquarie University, NSW 2109, Australia.
Roger G
RG
Hiller
Department of Quantum Electronics, Faculty of Physics, Vilnius University, Saulėtekio av. 10, LT-10223 Vilnius, Lithuania.
Mikas
M
Vengris
D002338:Carotenoids / Q000737:chemistry*; D002734:Chlorophyll / Q000737:chemistry*; D000077194:Chlorophyll A; D004735:Energy Transfer; D007700:Kinetics; D013057:Spectrum Analysis
D002734:Chlorophyll; C016040:peridinin; D002338:Carotenoids; D000077194:Chlorophyll A
Excitation energy transfer; Excited state equilibrium; Intramolecular charge transfer; Peridinin-chlorophyll a-protein; Pump-dump-probe; Pump-probe