Mechanical Forces Alter Conical Intersections Topology

  1. Rivero, D. 3
  2. Valentini, A. 23
  3. Fernández-González, M.A. 3
  4. Zapata, F. 3
  5. García-Iriepa, C. 13
  6. Sampedro, D. 1
  7. Palmeiro, R. 3
  8. Frutos, L.M. 3
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Università degli Studi di Siena
    info

    Università degli Studi di Siena

    Siena, Italia

    ROR https://ror.org/01tevnk56

  3. 3 Universidad de Alcalá
    info

    Universidad de Alcalá

    Alcalá de Henares, España

    ROR https://ror.org/04pmn0e78

Revista:
Journal of Chemical Theory and Computation

ISSN: 1549-9618

Any de publicació: 2015

Volum: 11

Número: 8

Pàgines: 3740-3745

Tipus: Article

DOI: 10.1021/ACS.JCTC.5B00375 SCOPUS: 2-s2.0-84938927373 GOOGLE SCHOLAR

Altres publicacions en: Journal of Chemical Theory and Computation

Resum

Photoreactivity can be influenced by mechanical forces acting over a reacting chromophore. Nevertheless, the specific effect of the external forces in the photoreaction mechanism remains essentially unknown. Conical intersections are key structures in photochemistry, as they constitute the funnels connecting excited and ground states. These crossing points are well known to provide valuable information on molecular photoreactivity, including crucial aspects as potential photoproducts which may be predicted by just inspection of the branching plane vectors. Here, we outline a general framework for understanding the effect of mechanical forces on conical intersections and their implications on photoreactivity. Benzene S<inf>1</inf>/S<inf>0</inf> conical intersection topology can be dramatically altered by applying less than 1 nN force, making the peaked pattern of the intersection become a sloped one, also provoking the transition state in the excited state to disappear. Both effects can be related to an increase in the photostability as the conical intersection becomes more accessible, and its topology in this case favors the recovery of the initial reactant. The results indicate that the presence of external forces acting over a chromophore have to be considered as a potential method for photochemical reactivity control. © 2015 American Chemical Society.