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The Radical Anions and Trianions of 1,8‐Diphenylnaphthalene and of Some of its Derivatives Containing a Cyclophane Substructure

1985; Wiley; Volume: 68; Issue: 7 Linguagem: Inglês

10.1002/hlca.19850680716

1522-2675

Fabian Gerson, René Heckendorn, Reinhart Möckel, Fritz Vögtle,

Radical Photochemical Reactions

Abstract The radical anions of 1,8‐diphenylnaphthalene ( 1 ) and its decadeuterio‐(D 10 ‐ 1 ) and dimethyl‐( 2 ) derivatives, as well as those of [2.0.0] (1,4)benzeno(1,8)naphthaleno(1,4)benzenophane ( 3 ) and its olefinic analogue ( 4 ) have been studied by ESR and ENDOR spectroscopy, At a variance with a previous report, the spin population in \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{-\kern-4pt {.}} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {2}^{-\kern-4pt {.}} $\end{document} is to a great extent localized in the naphthalene moiety. A similar spin distribution is found for \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {3}^{-\kern-4pt {.}} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {4}^{-\kern-4pt {.}} $\end{document} . The ground conformations of \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{-\kern-4pt {.}} $\end{document} ‐ \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {4}^{-\kern-4pt {.}} $\end{document} are chiral of C 2 symmetry. For \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{-\kern-4pt {.}} $\end{document} , an energy barrier between these conformations and the angle of twist about the bonds linking the naphthalene moiety with the phenyl substituents were estimated as ca. 50 kJ/mol and ca. 45°, respectively. The radical trianions of 1 , D 10 ‐ 1 , and 2 , have also been characterized by their hyperfine data. In \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{3-\kern-4pt {.}} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {2}^{3-\kern-4pt {.}} $\end{document} , the bulk of the spin population resides in the two benzene rings so that these radical trianions can be regarded as the radical anions of ‘open‐chain cyclophanes’ with a fused naphthalene π‐system bearing almost two negative charges. The main features of the spin distribution in both \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{-\kern-4pt {.}} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ \rm {1}^{3-\kern-4pt {.}} $\end{document} are correctly predicted by an HMO model of 1 .