| Autor: |
Peter P. Levin, V. Ya. Shafirovich, Elena E. Batova |
| Rok vydání: |
1991 |
| Předmět: |
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| Zdroj: |
Photochemical Conversion and Storage of Solar Energy ISBN: 9789401055024 |
| DOI: |
10.1007/978-94-011-3396-8_4 |
| Popis: |
The design of the supramolecules: Zn-porphyrin-viologen dyads and Zn-porphyrin-viologen-quinone triads, which give rise to charge separation and stabilization after absorption of visible light in polar media has been developed. The photoinduced charge separation is achieved by the competition of the fast spin-allowed forward and backward spin-forbidden electron transfers (ETs). An external magnetic field is used to control the recombination of the triplet radical ion pair (RIP) state formed in a primary photochemical reaction. The triplet RIP state is stabilized by the subsequent ET to the second electron acceptor (quinone) which is linked to the first one. The mechanism of the triplet-singlet (T-S) evolution of RIPs and the magnetic field effect on their recombination is discussed in respect of the different behaviour of RIPs in several conformers. In the opened conformer of the RIP (with a small value of the exchange interaction (J) between radical centers) the hyperfine coupling (hfc) and the relaxation mechanisms of T-S evolution of the RIP are active; in the closed conformer of the RIP, where J is large enough (2J >> Ahfc), the spin-orbit coupling (SOC) dominates. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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