Photostability via a Sloped Conical Intersection: A CASSCF and RASSCF Study of Pyracylene
Authors:
- 14 September 2005
- journal article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry A
- Vol. 109 (39) , 8849-8856
Abstract
An extensive ab initio study of the ground- and excited-state potential energy surfaces of pyracylene is presented in this work. CASSCF calculations show that there is an accessible sloped S0/S1 conical intersection, which leads to ultrafast internal conversion and explains the observed photostability. RASSCF calculations (using a well-defined subset of the CASSCF configurations) are shown to be able to reproduce CASSCF results satisfactorily and will therefore be useful for larger systems where CASSCF is currently too expensive. MRCI and MRPT2 energy corrections are computed to assess the ionic character of the excited states. Finally, MMVB calculations are also benchmarked against CASSCF, to assess the reliability of this parametrized method for excited states of large conjugated polycyclic aromatic hydrocarbons.Keywords
This publication has 58 references indexed in Scilit:
- On the Correlation Energy of π-Electrons in Planar HydrocarbonsThe Journal of Physical Chemistry A, 2000
- Molecular and electronic structure of pyracyleneJournal of the American Chemical Society, 1990
- The UV absorption spectrum of C60 (buckminsterfullerene): A narrow band at 3860 ÅThe Journal of Chemical Physics, 1987
- Carbon-13 nuclear magnetic resonance and ring currents in vinyl cross-linked annulenesJournal of the American Chemical Society, 1976
- Diphenylene oxide and cyclopentacenaphthylene(s) in flame sootsEnvironmental Science & Technology, 1973
- High-resolution mass spectrometric investigation of heteroatom species in coal-carbonization productsFuel, 1972
- Perturbed [12]annulenes. Synthesis of pyracylenesJournal of the American Chemical Society, 1971
- Novel reduction by diiron nonacarbonylJournal of the American Chemical Society, 1969
- Additions and Corrections - Pyracylene. A Pentalenoid System?Journal of the American Chemical Society, 1968
- Pyracylene. Pentalenoid systemJournal of the American Chemical Society, 1967