title: Photochemical Reactions of Cyclohexanone: Mechanisms and Dynamics.
abstract: Photochemistry of carbonyl compounds is of major importance in atmospheric and organic chemistry. The photochemistry of cyclohexanone is studied here using on-the-fly molecular dynamics simulations on a semiempirical multireference configuration interaction potential-energy surface to predict the distribution of photoproducts and time scales for their formation. Rich photochemistry is predicted to occur on a picosecond time scale following the photoexcitation of cyclohexanone to the first singlet excited state. The main findings include: (1) Reaction channels found experimentally are confirmed by the theoretical simulations, and a new reaction channel is predicted. (2) The majority (87%) of the reactive trajectories start with a ring opening via C-Cα bond cleavage, supporting observations of previous studies. (3) Mechanistic details, time scales, and yields are predicted for all reaction channels. These benchmark results shed light on the photochemistry of isolated carbonyl compounds in the atmosphere and can be extended in the future to photochemistry of more complex atmospherically relevant carbonyl compounds in both gaseous and condensed-phase environments.
authors.affiliation: Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University , Jerusalem 91904, Israel.
authors.forename: Dorit
authors.initials: D
authors.lastname: Shemesh
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Nizkorodov
authors.affiliation: Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University , Jerusalem 91904, Israel.|Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: R Benny
authors.initials: RB
authors.lastname: Gerber