| Autor: |
Grigoriy Sereda, Jesse Van Heukelom, Miles Koppang, Sudha Ramreddy, Nicole Collins |
| Jazyk: |
angličtina |
| Rok vydání: |
2006 |
| Předmět: |
|
| Zdroj: |
Beilstein Journal of Organic Chemistry, Vol 2, Iss 1, p 26 (2006) |
| Druh dokumentu: |
article |
| ISSN: |
1860-5397 |
| DOI: |
10.1186/1860-5397-2-26 |
| Popis: |
BackgroundBetter understanding of the transannular influence of a substituent on the redox-potentials of bicyclo[2.2.2]octane-derived quinones will help in the design of new compounds with controlled biological activity. However, attempts to directly relate the reduction potentials of substituted triptycene-quinones to the electronic effects of substituents are often unsuccessful.ResultsFirst and second redox-potentials of a series of bicyclic quinones are compared to computed energies of their LUMO, LUMO+1, and energies of reduction. Transannular influence of substituent on the redox-potentials is rationalized in terms of MO theory. Acetoxy-substituents in the 5,8-positions of the triptycene-quinone system selectively destabilize the product of the two-electron reduction.ConclusionWe have shown that first redox-potentials of substituted bicyclic quinones correlate with their calculated LUMO energies and the energies of reduction. The second redox-potentials correlate with calculated LUMO+1 energies. As opposed to the LUMO orbitals, the LUMO+1 orbital coefficients are weighted significantly on the non-quinone part of the bicyclic system. This accounts for: (1) significantly larger substituent effect on the second redox-potentials, than on the first redox-potentials; (2) lack of stability of the product of two electron reduction of 5,8-diacetoxy-9,10-dihydro-9,10-[1,2]benzenoanthracene-1,4-dione 5. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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