Face-to-face pacman-type porphyrin-fullerene dyads: design, synthesis, charge-transfer interactions, and photophysical studies.
Pacman-type face-to-face zinc-porphyrin-fullerene dyads have been newly synthesized and studied. Owing to the close proximity of the donor and acceptor entities, strong pi-pi intramolecular interactions between the porphyrin and fullerene entities resulted in modulating the spectral and electrochemical properties of the dyads. New absorption and emission bands that correspond to the charge-transfer interactions were observed in the near-IR region. Time-resolved transient absorption studies revealed efficient photoinduced electron transfer from the singlet excited porphyrin to the fullerene entity. The rate constants for photoinduced electron transfer are analyzed in terms of the Marcus theory of electron transfer, which afforded a large electron coupling matrix element (V=140 cm(-1)) for the face-to-face dyads. As a consequence of the large charge-recombination driving force in the Marcus inverted region, a relatively long lifetime of the charge-separated state has been achieved.
D'Souza
Francis
F
Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260-0051, USA.
Maligaspe
Eranda
E
Karr
Paul A
PA
Schumacher
Amy Lea
AL
El Ojaimi
Maya
M
Gros
Claude P
CP
Barbe
Jean-Michel
JM
Ohkubo
Kei
K
Fukuzumi
Shunichi
S
D019281:Dimerization; D004579:Electron Transport; D037741:Fullerenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013997:Time Factors; D015032:Zinc / Q000737:chemistry*
D037741:Fullerenes; D009942:Organometallic Compounds; D011166:Porphyrins; D015032:Zinc