K. Nakabayashi, S. Takamuku
Nov 1, 1992
Citations
0
Influential Citations
4
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The mechanism of valence isomerization between methyl 5-(4-biphenylyl) tetracyclo [3.2.0.2,70.4,6] heptane-1-carboxylate (1) and methyl 3-(4-biphenylyl)bicyclo[2.2.1]hepta-2,5-diene-2-carboxylate (2) under the triplet sensitization in benzene was studied by γ-radiolysis and pulse radiolysis. As an intermediate for the isomerization, an equilibrium state between a 1,3-biradical intermediate and a triplet state with the structure of norbornadiene has been estimated. The triplet energy levels of 1 and 2 were determined to be 59 and 57 kcal mol−1, respectively. The energy difference between the ground states of 1 and 2 was determined to be 18 kcal mol−1.