No abstract

No abstract

The radical anions of homoazulene (1,5-methano[ 10] annulene, 1) and two of its deuterio derivatives have been studied by ESR and, in part, by ENDOR spectroscopy. The compound 1 is reduced to the radical anion at less negative potential (E¡/j = -1.94 V) than the isomeric 1,6-methano[ 10]annulene (2) (-2.21 V), but V" is markedly less persistent than 2'~. The most prominent hyperfine feature of V" is the very large splitting (1.342 mT) from the exo proton in the methano bridging group. The next largest coupling constants (0.685 and 0,432 mT) are due to the protons at the -centers situated in the mirror plane (m) of 1. Both the Ex¡t value of 1 and the hyperfine data for 1*~indicate that the SOMO in 1"" correlates with one of the lowest antibonding perimeter MO's (fs) which is symmetric with respect to the plane m. The decrease in energy of i/'s relative to its antisymmetric counterpart (ff) is attributed to homoconjugation which should be particularly favored in

No abstract

No abstract