title: Quantum chain reaction of tethered diarylcyclopropenones in the solid state and their distance-dependence in solution reveal a Dexter S₂-S₂ energy-transfer mechanism.
abstract: When promoted to their second singlet excited state (S2) in benzene, alkyl-linked dimers of diarylcyclopropenone undergo a photodecarbonylation reaction with quantum yields varying from Φ = 0.7 to 1.14. Quantum yields greater than 1.0 in solution rely on an adiabatic reaction along the S2 energy surface where the immediately formed excited-state product transfers energy to the unreacted molecule in the dimer to generate a second excited state. By determination of the quantum yields of decarbonylation for the linked diarylcyclopropenones with linkers of various lengths it was shown that S2 → S2 energy transfer is limited to distances shorter than ca. 6 Å. Notably, the quantum chain reaction occurs with similar efficiency for all the linked diarylcyclopropenones dimers in the solid state.
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
authors.forename: Amy
authors.initials: A
authors.lastname: Nielsen
authors.forename: Gregory
authors.initials: G
authors.lastname: Kuzmanich
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Garcia-Garibay