Photodissociation of phosgene: Theoretical evidence for the ultrafast and synchronous concerted three-body process
2009 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 131, no 16Article in journal (Refereed) Published
The potential energy surfaces for Cl2CO dissociation into CO+Cl+Cl in the lowest two electronic singlet states (S-0 and S-1) have been determined by the complete active space self-consistent field, coupled-cluster method with single and double excitations (CCSD), and equation-of-motion CCSD calculations, which are followed by direct ab initio molecular dynamics simulations to explore its photodissociation dynamics at 230 nm. It is found that the C-O stretching mode is initially excited upon irradiation and the excess internal energies are transferred to the C-Cl symmetric stretching mode within 200 fs. On average, the first and the second C-Cl bonds break completely within subsequent 60 and 100 fs, respectively. Electronic structure and dynamics calculations have thus provided a strong evidence that the photoinitiated dissociation of Cl2CO at 230 nm or shorter wavelengths is an ultrafast, adiabatic, and concerted three-body process. Since the two C-Cl bonds begin to break at the same time and the time interval between the two C-Cl bond broken fully is very short (similar to 40 fs), the photoinitiated dissociation of Cl2CO to CO+2Cl can be considered as the synchronous concerted process.
Place, publisher, year, edition, pages
2009. Vol. 131, no 16
3 body decay, initio molecular-dynamics, excited-state topology, sym-triazine, glyoxal photodissociation, dissociation, nm, chloride, photolysis, ethylene
IdentifiersURN: urn:nbn:se:kth:diva-18925DOI: 10.1063/1.3253048ISI: 000271358400034ScopusID: 2-s2.0-72049092701OAI: oai:DiVA.org:kth-18925DiVA: diva2:336972
QC 201005252010-08-052010-08-052011-02-07Bibliographically approved