Effects of chain length on behavior of biradicals generated from Norrish type I reaction of 2,2-diphenylcycloalkanones. Isolation and photochemistry of intermediate methylenecyclohexadienyl ketones
The reaction course of biradicals, OC↑-(CH2)n−2-C↑Ph2, generated from Norrish typeI reaction of 2,2-diphenylcycloalakanones with various ring sizes, is switched from intramolecular disproportionation (n=6,7) to acyl-phenyl recombination (n>-9) in methanol.