All over the world, research groups are working on solving the energy supply. One way might be to mimic the Nature photosynthesis to be able to transform water to hydrogen gas. In the artificial photosynthesis one crucial task is to find a system that can produce charge separation from sunlight. Such system should contain a photoactive moiety that absorbs the sunlight and transfer an electron to an electron acceptor. Dyads of this type based on C60 as the electron acceptor have been studied by many groups the recent years.[2-4] Common for most of these dyads are that the distance between the fullerene and the photoactive moiety is rather large to make the life-time of the charge separated state as long as possible.
Depending on the way the linker is attached to the fullerene its electron accepting ability is altered. Usually it is decreased with approximately 100 mV compared to pristine C60 but when electron deficient carbons or heteroatoms are attached directly to the fullerene core, e.g. pyrazolines and triazolines) the electron acceptance is increased by almost the same voltage.
To study the electron transfer process various dyads between fullerene C60 and various ruthenium bipyridine complexes will be synthesised. They will be linked together by short spacers connected to the fullerene core in different ways.
(1) Sun, L. C.; Hammarstrom, L.; Akermark, B.; Styring, S. Chem. Soc. Rev.2001, 30, 36-49.
(2) Martin, N.; Sanchez, L.; Illescas, B.; Perez, I. Chemical Reviews1998, 98, 2527-2547.
(3) Diederich, F.; Gomez-Lopez, M. Chem. Soc. Rev.1999, 28, 263-277.
(4) Prato, M.; Maggini, M. Accounts Chem. Res.1998, 31, 519-526.
(5) Langa, F.; de la Cruz, P.; Espildora, E.; de la Hoz, A.; Bourdelande, J. L.; Sanchez, L.; Martin, N. Journal of Organic Chemistry2001, 66, 5033-5041.
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