The photochemistry of optically pure isomers of α-methylbenzylamide of trans-2,3-diphenylcyclopropane-1-carboxylic acid has been examined in isotropic solution and within zeolites. The results suggest that these isomerize through cleavage of C2-C3 bond. The direct excitation in solution leads to non-equilibrating 1,3-singlet diradical intermediates whereas triplet sensitization results in equilibrating 1,3-triplet diradical intermediates. The direct excitation within Na Y zeolite seems to result in equilibrating zwitterionic intermediates. Studies on the optically pure trans isomers allow one to understand the mechanism of chiral induction during the photoisomerization of meso cis-2,3-diphenylcyclopropane-1-carboxylic acid. The current study has clarified the nature of the excited states involved during the classic (R)-N-acetyl-1-naphthylethylamine sensitized isomerization of 1,2-diphenylcyclopropane.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry