Ab initio reaction pathways for photodissociation and isomerization of nitromethane on four singlet potential energy surfaces with three roaming paths

Miho Isegawa, Fengyi Liu, Satoshi Maeda, Keiji Morokuma

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Photodissociation pathways of nitromethane following π → π electronic excitation are reported. The potential energy surfaces for four lowest singlet states are explored, and structures of many intermediates, dissociation limits, transition states, and minimum energy conical intersections were determined using the automated searching algorism called the global reaction route mapping strategy. Geometries are finally optimized at CASSCF(14e,11o) level and energies are computed at CAS(14o,11e)PT2 level. The calculated preferable pathways and important products qualitatively explain experimental observations. The major photodissociation product CH3 and NO2 (2B2) is formed by direct dissociation from the S1 state. Important pathways involving S1 and S0 states for production of various dissociation products CH 3NO + O (1D), CH3O(X2E) + NO (X 2Π ), CH2NO + OH, and CH2O + HNO, as well as various isomerization pathways have been identified. Three roaming processes also have been identified: the O atom roaming in O dissociation from CH 3NO2, the OH radical roaming in OH dissociation from CH2N(O)(OH), and the NO roaming in NO dissociation from CH 3ONO.

Original languageEnglish
Article number244310
JournalJournal of Chemical Physics
Volume140
Issue number24
DOIs
Publication statusPublished - Jan 1 2014

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Photodissociation
Potential energy surfaces
nitromethane
Isomerization
photodissociation
isomerization
potential energy
dissociation
methylidyne
products
intersections
routes
Atoms
Geometry
energy
geometry
electronics
excitation
atoms

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Ab initio reaction pathways for photodissociation and isomerization of nitromethane on four singlet potential energy surfaces with three roaming paths. / Isegawa, Miho; Liu, Fengyi; Maeda, Satoshi; Morokuma, Keiji.

In: Journal of Chemical Physics, Vol. 140, No. 24, 244310, 01.01.2014.

Research output: Contribution to journalArticle

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AU - Morokuma, Keiji

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