Dynamics starting at a conical intersection: Application to the photochemistry of pyrrole

Journal Article · Tue Jul 14 00:00:00 EDT 2009 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3175799· OSTI ID:21559865

Sellner, Bernhard; Barbatti, Mario ^[1]; Lischka, Hans ^[1]

---

1. Institute for Theoretical Chemistry, University of Vienna, Waehringerstrasse 17, A-1090 Vienna (Austria)

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 et al., 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-C{sub 3}H{sub 3}) is observed. The computed structural data correlate well with the experimentally observed dissociation products.

• OSTI ID: 21559865
• Journal Information: Journal of Chemical Physics, Vol. 131, Issue 2; Other Information: DOI: 10.1063/1.3175799; (c) 2009 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ATOMS
BRANCHING RATIO
CALCULATION METHODS
DISSOCIATION
DISTRIBUTION
PHOTOCHEMISTRY
PROPARGYL RADICALS
PYRROLES
REACTION KINETICS
RINGS
SELF-CONSISTENT FIELD
SIMULATION
ALKYL RADICALS
AZOLES
CHEMISTRY
DIMENSIONLESS NUMBERS
HETEROCYCLIC COMPOUNDS
KINETICS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADICALS