The triplet photochemistry of l, l-dicyano-5, 5-diphenyl-3, 3-diisopropyl-l, 4-pentadiene was investigated to determine if the high reactivity of di-? r-methane systems with central diphenyl substitution derived from electronic or from steric effects. Sensitized photolysis of the dicyanopentadiene afforded l, l-dicyano-2-(2, 2-diphenyl-vinyl)-3, 3- diisopropylcyclopropane as the singlet photoproduct with an efficiency of q!= 0.041. This is ...
