Mv. Barnabas et al., QUADRICYCLANE AND NORBORNADIENE RADICAL CATIONS IN SILICALITE - COMPARISON WITH FREON MATRICES, Chemical physics letters, 206(1-4), 1993, pp. 21-24
The radical cation of nonbornadiene is produced by gamma radiolysis of
nonbornadiene or quadricyclane in silicalite at 77 K. The bicyclo[3.2
.0]hepta-2,6-diene radical cation and the bicyclo[2.2.1]hepta-2,5-dien
e-7-yl radical are observed at higher temperatures. The same radical c
ation chemistry was recently examined by EPR in freon matrices, and di
fferences with this EPR study in zeolites are discussed. Some zeolite
sites must be able to stabilize higher electronic states of radical ca
tions, enabling otherwise photochemical processes to be thermally acce
ssible in zeolites.