TY - JOUR
T1 - Dynamics starting at a conical intersection
T2 - Application to the photochemistry of pyrrole
AU - Sellner, Bernhard
AU - Barbatti, Mario
AU - Lischka, Hans
N1 - Funding Information:
This work was supported by the Austrian Science Fund within the framework of the Special Research Program F16 (Advanced Light Sources) and Project No. P18411-N19. Support by the grant from the Ministry of Education of the Czech Republic (Center for Biomolecules and Complex Molecular Systems, No. LC512) and by the Praemium Academiae of the Academy of Sciences of the Czech Republic, awarded to Pavel Hobza in 2007, is gratefully acknowledged. This work was part of the research Project No. Z40550506 of the Institute of Organic Chemistry and Biochemistry of the Academy of Sciences of the Czech Republic. The authors also acknowledge the support of COST action under Grant No. CM0702. The calculations were partially performed at the Linux PC cluster Schrödinger III of the computer center of the University of Vienna.
PY - 2009
Y1 - 2009
N2 - The photochemical ring opening process in pyrrole has been investigated by performing classical on-the-fly dynamics using the multiconfiguration self-consistent field method for the computation of energies and energy gradients. As starting point for the dynamics the conical intersection corresponding to the ring-puckered ring-opened structure, determined previously [Barbatti, J. Chem. Phys. 125, 164323 (2006)], has been chosen. Two sets of initial conditions for the nuclear velocities were constructed: (i) nuclear velocities in the branching (g,h) plane of the conical intersection and (ii) statistical distribution for all atoms. Both sets of initial conditions show very similar results. Reactive trajectories are only found in a very limited sector in the (g,h) plane and reaction products are very similar. Within the simulation time of 1 ps, ring opening of pyrrole to the biradical NH=CH- CH -CH= CH chain followed by ring closure to a substituted cyclopropene structure (NH=CH- C3 H3) is observed. The computed structural data correlate well with the experimentally observed dissociation products.
AB - The photochemical ring opening process in pyrrole has been investigated by performing classical on-the-fly dynamics using the multiconfiguration self-consistent field method for the computation of energies and energy gradients. As starting point for the dynamics the conical intersection corresponding to the ring-puckered ring-opened structure, determined previously [Barbatti, J. Chem. Phys. 125, 164323 (2006)], has been chosen. Two sets of initial conditions for the nuclear velocities were constructed: (i) nuclear velocities in the branching (g,h) plane of the conical intersection and (ii) statistical distribution for all atoms. Both sets of initial conditions show very similar results. Reactive trajectories are only found in a very limited sector in the (g,h) plane and reaction products are very similar. Within the simulation time of 1 ps, ring opening of pyrrole to the biradical NH=CH- CH -CH= CH chain followed by ring closure to a substituted cyclopropene structure (NH=CH- C3 H3) is observed. The computed structural data correlate well with the experimentally observed dissociation products.
UR - http://www.scopus.com/inward/record.url?scp=67650721755&partnerID=8YFLogxK
U2 - 10.1063/1.3175799
DO - 10.1063/1.3175799
M3 - Article
C2 - 19603996
AN - SCOPUS:67650721755
VL - 131
JO - The Journal of Chemical Physics
JF - The Journal of Chemical Physics
SN - 0021-9606
IS - 2
M1 - 024312
ER -