Elucidation and Control of an Intramolecular Charge Transfer Property of Fucoxanthin by a Modification of Its Polyene Chain Length.
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 presence of the carbonyl group in its polyene backbone. This report describes the excited state properties of fucoxanthin homologues with four to eight conjugated double bonds in various solvents using the femtosecond pump-probe technique. The results clarified that fucoxanthin homologues with longer polyene chains did not possess pronounced ICT spectroscopic signatures, while the shorter fucoxanthin homologues had a strong ICT character, even in a nonpolar solvent. On the basis of the observations, we quantitatively correlated the ICT character in the excited state to the conjugated polyene chain lengths of fucoxanthin molecules.
†Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Daisuke
D
Kosumi
‡Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337, Japan.
Takayuki
T
Kajikawa
‡Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337, Japan.
Satoshi
S
Okumura
§Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Mitsuru
M
Sugisaki
∥Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Kazuhiko
K
Sakaguchi
‡Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337, Japan.
Shigeo
S
Katsumura
†Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.|§Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Hideki
H
Hashimoto
and excited state dynamics; intramolecular charge transfer; photosynthesis; ultrafast spectroscopy