Spectroscopic Analysis of a Biomimetic Model of Tyr(Z) Function in PSII.
Using natural photosynthesis as a model, bio-inspired constructs for fuel generation from sunlight are being developed. Here we report the synthesis and time-resolved spectroscopic analysis of a molecular triad in which a porphyrin electron donor is covalently linked to both a cyanoporphyrin electron acceptor and a benzimidazole-phenol model for the TyrZ-D1His190 pair of PSII. A dual-laser setup enabled us to record the ultrafast kinetics and long-living species in a single experiment. From this data, the photophysical relaxation pathways were elucidated for the triad and reference compounds. For the triad, quenching of the cyanoporphyrin singlet excited state lifetime was interpreted as photoinduced electron transfer from the porphyrin to the excited cyanoporphyrin. In contrast to a previous study of a related molecule, we were unable to observe subsequent formation of a long-lived charge separated state involving the benzimidazole-phenol moiety. The lack of detection of a long-lived charge separated state is attributed to a change in energetic landscape for charge separation/recombination due to small differences in structure and solvation of the new triad.
Department of Physics and Astronomy, Faculty of Sciences, VU University , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Janneke
J
Ravensbergen
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Antaeres
A
Antoniuk-Pablant
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Benjamin D
BD
Sherman
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Gerdenis
G
Kodis
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Jackson D
JD
Megiatto
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Dalvin D
DD
Méndez-Hernández
Department of Physics and Astronomy, Faculty of Sciences, VU University , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Raoul N
RN
Frese
Department of Physics and Astronomy, Faculty of Sciences, VU University , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Rienk
R
van Grondelle
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Thomas A
TA
Moore
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Ana L
AL
Moore
Department of Chemistry & Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University , Tempe, Arizona 85287-1605, United States.
Devens
D
Gust
Department of Physics and Astronomy, Faculty of Sciences, VU University , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
John T M
JT
Kennis
D001562:Benzimidazoles / Q000737:chemistry*; D032701:Biomimetics; D004579:Electron Transport; D004735:Energy Transfer; D008958:Models, Molecular; D019800:Phenol / Q000737:chemistry*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D013057:Spectrum Analysis; D014443:Tyrosine / Q000737:chemistry*
D001562:Benzimidazoles; D045332:Photosystem II Protein Complex; D011166:Porphyrins; D019800:Phenol; D014443:Tyrosine; C031000:benzimidazole