Angewandte Chemie - International Edition 53 6715-6719 2014年6月
The excited-state dynamics of pentacene derivatives with stable radical substituents were evaluated in detail through transient absorption measurements. The derivatives showed ultrafast formation of triplet excited state(s) in the pentacene moiety...
Ultrafast excited state dynamics of the short fucoxanthin homolog with four conjugated double bonds and its allene-modified analog in various solvents have been studied by femtosecond pump-probe spectroscopy. The results clarified that the short f...
Journal of Physical Chemistry Letters 5 792-797 2014年3月
Fucoxanthin is an essential pigment for the highly efficient light-harvesting function of marine algal photosynthesis. It exhibits excited state properties attributed to intramolecular charge transfer (ICT) in polar environments due to the presenc...
Fucoxanthin is an essential pigment for the light-harvesting of aquatic algae. It exhibits high energy transfer efficiencies to Chl a (>80%) as well as peridinin (>95%). In order to verify the generality and specificity of the noticeable observati...
D. Kosumi, T. Kajikawa, K. Yano, S. Okumura, M. Sugisaki, K. Sakaguchi, S. Katsumura, H. Hashimoto, H. Hashimoto
Optics InfoBase Conference Papers 2014年1月
Ultrafast Intramolecular Charge Transfer (ICT) state dynamics of fucoxanthin have been investigated by femtosecond pump-probe measurements. A modification of conjugated polyene chain length of fucoxanthin enabled us to clarify and control an ICT c...
Fucoxanthin, containing a carbonyl group in conjugation with its polyene backbone, is a naturally occurring pigment in marine organisms and is essential to the photosynthetic light-harvesting function in brown alga and diatom. Fucoxanthin exhibits...
D. Kosumi, S. Maruta, R. Fujii, R. Fujii, M. Sugisaki, S. Takaichi, R. J. Cogdell, H. Hashimoto, H. Hashimoto
Optics InfoBase Conference Papers 2014年1月
Ultrafast energy transfer dynamics in photosynthetic antennas were investigated by femtosecond pump-probe measurements. Photo-excited carotenoids with short-polyene chains efficiently transfer energy to bacteriochlorophylls, while the energy rapid...
Ultrafast excited-state dynamics of the photosynthetic pigment (Mg-)bacteriochlorophyll a and its Zn-substituted form were investigated by steady-state absorption/fluorescence and femtosecond pump-probe spectroscopic measurements. The obtained ste...
D. Kosumi, D. Kosumi, M. Kita, M. Kita, R. Fujii, R. Fujii, M. Sugisaki, M. Sugisaki, N. Oka, Y. Takaesu, T. Taira, M. Iha, H. Hashimoto, H. Hashimoto, H. Hashimoto
Journal of Physical Chemistry Letters 3 2659-2664 2012年9月
Fucoxanthin-chlorophyll-a/c protein (FCP) complexes from brown algae Cladosiphon okamuranus TOKIDA (Okinawa Mozuku in Japanese) contain the only species of carbonyl carotenoid, fucoxanthin, which exhibits spectral characteristics attributed to an ...
Ultrafast excited state dynamics of spirilloxanthin in solution and bound to the light-harvesting core antenna complexes from Rhodospirillum rubrum S1 were investigated by means of femtosecond pump-probe spectroscopic measurements. The previously ...
Ultrafast photoexcitation dynamics of the bodipy-anthracene-radical triad of the photoexcited quartet state and its control compounds were investigated by fs-laser spectroscopy. The fs-spectroscopy successfully unveiled complicated dynamical proce...
Physical Review B - Condensed Matter and Materials Physics 85 2012年6月
Coherent vibronic oscillations in the ground state of carotenoids have been investigated by means of three-pulse four-wave mixing spectroscopy. Here, we especially focused our attention on the influence of the temporal separation between the first...
Fucoxanthin exhibits high energy transfer efficiencies to Chlorophyll a (Chl a) in photosynthesis in the sea. In order to reveal how each characteristic functional group, such as the length of the polyene chain, allene, and conjugated carbonyl gro...
S. Maruta, D. Kosumi, T. Horibe, R. Fujii, M. Sugisaki, M. Sugisaki, R. J. Cogdell, H. Hashimoto, H. Hashimoto
Physics Procedia 13 58-61 2011年6月
Ultrafast excited state dynamics of carotenoids in solution and bound to pigment-protein complexes have been investigated by means of femtosecond pump-probe spectroscopic measurements. Ultrafast triplet formation of carotenoids bound to pigmentpro...
Mitsuru Sugisaki, Daisuke Kosumi, Keisuke Saito, Richard J. Cogdell, Hideki Hashimoto, Hideki Hashimoto
Physics Procedia 13 74-77 2011年6月
The four-wave mixing signals from spheroidene have been systematically investigated at various coherent periods r. The pronounced vibronic oscillations of the fundamental modes in the ground state are clearly observed in the transient grating conf...
Physical Chemistry Chemical Physics 13 10762-10770 2011年6月
Carotenoids containing a carbonyl group in conjugation with their polyene backbone are naturally-occurring pigments in marine organisms and are essential to the photosynthetic light-harvesting function in aquatic algae. These carotenoids exhibit s...
Physical Review B - Condensed Matter and Materials Physics 83 2011年5月
Excitons, photocarriers, and bias-induced carriers in regioregular poly(3-alkylthiophene) (P3AT) films were investigated using a variety of spectroscopic techniques, such as continuous-wave- (cw-) and femtosecond (fs-) transient photoinduced absor...
Toshiyuki Kusumoto, Daisuke Kosumi, Chiasa Uragami, Harry A. Frank, Robert R. Birge, Richard J. Cogdell, Hideki Hashimoto, Hideki Hashimoto
Journal of Physical Chemistry A 115 2110-2119 2011年3月
The photophysical properties of a carbonyl-containing carotenoid analogue in an s-cis configuration, relative to the conjugated π system, 2-(all-trans-retinylidene)-indan-1,3-dione (C20Ind), were investigated by femtosecond time-resolved spectrosc...
Ultrafast relaxation kinetics of fucoxanthin in polar and non-polar solvents have been studied by femtosecond pump-probe spectroscopy. Transient absorption associated with S1 or intramolecular charge transfer (ICT) excited state has been observed ...
Daisuke Kosumi, Satoshi Maruta, Tomoko Horibe, Ritsuko Fujii, Mitsuru Sugisaki, Richard J. Cogdell, Hideki Hashimoto
Angewandte Chemie - International Edition 50 1097-1100 2011年2月
Reaping a good light harvest: Femtosecond spectroscopy uncovered a novel pathway of singlet-singlet excitation-energy transfer (EET) from bacteriochlorophyll (Bchl) in a purple bacterium to the carotenoid spirilloxanthin (Spx) upon the excitation ...
Physica Status Solidi (B) Basic Research 248 403-407 2011年2月
Ultrafast excited state dynamics of carotenoids in solution and bound to pigment-protein complexes have been investigated by femtosecond pump-probe spectroscopic measurements. Possible excitation energy transfer (EET) pathways between carotenoids ...
Physica Status Solidi (C) Current Topics in Solid State Physics 8 92-95 2011年1月
Ultrafast excited state dynamics of the photosynthetic pigment bacteriochlorophyll a in solution have been investigated by means of steady-state and time-resolved spectroscopic techniques. Photo-induced absorption spectra were observed upon excita...
Physica Status Solidi (C) Current Topics in Solid State Physics 8 88-91 2011年1月
The photophysics of the regioregular (RR) poly(3-alkylthiophene) (P3AT) films is investigated by cw-photoinduced absorption (PIA) measurements based on bleaching signals. The photoexcitation intensity dependence of the cw-PIA signals demonstrates ...
Mitsuru Sugisaki, Mitsuru Sugisaki, Daisuke Kosumi, Keisuke Saito, Keisuke Saito, Richard J. Cogdell, Hideki Hashimoto, Hideki Hashimoto
Physica Status Solidi (C) Current Topics in Solid State Physics 8 151-154 2011年1月
The nonlinear optical responses of carotenoids can be investigated by means of the four-wave mixing (FWM) spectroscopy. Here we especially focus on the relationship among the pulse sequences, temporal separations between the pulses and the resulti...
D. Kosumi, S. Maruta, T. Kusumoto, R. Fujii, M. Sugisaki, M. Iha, H. A. Frank, H. Hashimoto
Optics InfoBase Conference Papers 2010年12月
The ultrafast excited state dynamics of fucoxanthin in a polar solvent have been investigated by femtosecond one- and two-photon pump-probe spectroscopic measurements. Transient absorption spectra and their kinetics depend strongly on excitation e...
Femtosecond one- and two-photon pump-probe dispersive spectroscopic measurements have been applied to the investigation of the vibrational relaxation kinetics of the dark S1 (21Ag-) state in β-carotene, combining a higher sensitive detection syste...
Mitsuru Sugisaki, Masazumi Fujiwara, Daisuke Kosumi, Ritsuko Fujii, Mamoru Nango, Mamoru Nango, Richard J. Cogdell, Hideki Hashimoto
Physical Review B - Condensed Matter and Materials Physics 81 2010年6月
The concurrent dynamics of the electronic excitation and vibronic oscillations of spheroidene have been investigated by means of the transient grating (TG) spectroscopy. The third-order optical responses of spheroidene in an organic solvent, in th...
The ultrafast relaxation kinetics of fucoxanthin in polar and non-polar solvents have been studied by femtosecond dispersed one- and two-photon pump-probe spectroscopies. Transient absorption kinetics of the lowest singlet S1 (21Ag -) state and/or...
Bleaching probe spectroscopy performed for regioregular poly(3-hexylthiophene) diodes reveals that coexistent morphological phases determine the conducting and optical properties of conjugated polymer films. Photoinduced absorption measurements de...
The ultrafast relaxation kinetics of all-trans- β -carotene homologs with varying numbers of conjugated double bonds n (n=7-15) and lycopene (n=11) has been investigated using femtosecond time-resolved absorption and Kerr-gate fluorescence spectro...
Physical Review B - Condensed Matter and Materials Physics 77 2008年4月
Single-walled carbon nanotubes (SWCNTs) encapsulating β -carotene are attractive components for enhancing optical functionalities of SWCNTs. We have investigated ultrafast dynamics of light-harvesting function of β -carotene. The relaxation kineti...
Ultrafast dynamics of the optically allowed S2 (1 1 Bu +) state in all-trans-carotenoids with a number of conjugated double bonds, n = 7-15, has been investigated by femtosecond Kerr-gate fluorescence spectroscopy. The lifetime of the S2 state is ...
Ultrafast optical phenomena in all-trans-β-carotene have been investigated by femtosecond absorption and fluorescence spectroscopy. Following a resonant pump pulse, both fluorescence and absorbance changes have a decay time of 150 fs. The signals ...
M. Yoshizawa, D. Kosumi, M. Komukai, K. Yanagi, K. Yanagi, H. Hashimoto, H. Hashimoto
Optics InfoBase Conference Papers 2006年1月
Carotenoids with several conjugation lengths have been investigated. Time-resolved absorbance change and fluorescence are explained by relaxation of excited states and nonlinear optical effects. A role of intermediate states between S2 and S1 is d...
D. Kosumi, M. Komukai, K. Yanagi, H. Hashimoto, M. Yoshizawa
IQEC, International Quantum Electronics Conference Proceedings 2005 710-711 2005年12月
Responses to femtosecond tunable excitation pulses have been investigated in carotenoids. Relaxation kinetics depends on excess vibrational energy given by photoexcitation. Nonlinear responses to non-resonant excitation is interpreted by resonance...
Excitation energy dependence of transmittance change has been investigated in β-carotene. The signal induced by nonresonant excitation is ascribed to the ac Stark effect and the two-photon absorption of the excitation and probe pulses in three-lev...
Ultrafast relaxation kinetics in β-carotene and lycopene has been investigated by femtosecond absorption and fluorescence spectroscopies using tunable excitation pulses. The transient signals induced by the photoexcitation with larger excess energ...
M. Yoshizawa, D. Kosumi, M. Komukai, K. Yanagi, H. Hashimoto
Springer Series in Chemical Physics 79 589-591 2004年12月
Ultrafast optical responses in β -carotene and lycopene depend on the pump wavelength. Excess vibrational energy induced by the photoexcitation remains longer than several picoseconds in the excited states and slows down the relaxation kinetics.
RECONSTITUTION OF THE LIGHT-HARVESTING 1 COMPLEX FROM A PURPLE PHOTOSYNTHETIC BACTERIUM RHODOSPIRILLUM RUBRUM G9+ WITH FUCOXANTHIN
小澄大輔
ICARP2017 2017年3月1日
TRIPLET EXCITED STATE DYNAMICS OF CHLOROPHYLL A AS REVEALED BY SUB-NS PUMP-PROBE SPECTROSCOPY
小澄大輔
ICARP2017 2017年3月1日
EXCITATION ENERGY TRANSFER AND DISSIPATION DYNAMICS IN PHOTOSYNTHETIC ANTENNA SYSTEMS[招待有り]
ICARP2017 2017年3月1日
Tactics to enhance the excitation energy-transfer efficiency in the light-harvesting system using the intra-molecular charge transfer character of carotenoids
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