An artificial photosynthetic antenna-reaction center complex
A model photosynthetic antenna consisting of four covalently linked zinc tetraarylporphyrins, (P{sub ZP}){sub 3}-P{sub ZP}, has been joined to a free base porphyrin-fullerene artificial photosynthetic reaction center, P-C{sub 60}, to form a (P{sub ZP}){sub 3}-P{sub ZC}-PC{sub 60} hexad. As revealed by time-resolved absorption and emissions studies, excitation of any peripheral zinc porphyrin moiety (P{sub ZP}) in 2-methyltetrahydrofuran solution is followed by singlet-singlet energy transfer to the central zinc porphyrin to give (P{sub ZP}){sub 3}-{sup 1}P{sub ZC}-P-C{sub 60} with a time constant of {approximately}50 ps. The excitation is passed on to the free base porphyrin in 240 ps to produce (P{sub ZP}){sub 3}-P{sub ZC}-{sup 1}P-C{sub 60}, which decays by electron transfer to the fullerene with a time constant of 3 ps. The (P{sub ZP}){sub 3}-P{sub ZC}-P{sup {center{underscore}dot}{plus}}-C{sub 60}{sup {center{underscore}dot}{minus}} charge-separated state thus formed has a lifetime of 1,330 ps, and is generated with a quantum yield of 0.70 based on light absorbed by the zinc porphyrin antenna. The complex thus mimics the basic functions of natural photosynthetic antenna systems and reaction center complexes.
- Research Organization:
- Arizona State Univ., Tempe, AZ (US)
- Sponsoring Organization:
- National Science Foundation (NSF); USDOE
- OSTI ID:
- 20000125
- Journal Information:
- Journal of the American Chemical Society, Vol. 121, Issue 37; Other Information: PBD: 22 Sep 1999; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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