Photodissociation of phosgene: Theoretical evidence for the ultrafast and synchronous concerted three-body process

Journal Article · Wed Oct 28 00:00:00 EDT 2009 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3253048· OSTI ID:21559799

Qiu, Fang; Feng, Zhang ^[1]; Lin, Shen; Weihai, Fang ^[1]; Yi, Luo ^[2]

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1. College of Chemistry, Beijing Normal University, Beijing 100875 (China)
2. Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-10691 Stockholm (Sweden)

The potential energy surfaces for Cl{sub 2}CO dissociation into CO+Cl+Cl in the lowest two electronic singlet states (S{sub 0} and S{sub 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 Cl{sub 2}CO 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 ({approx}40 fs), the photoinitiated dissociation of Cl{sub 2}CO to CO+2Cl can be considered as the synchronous concerted process.

• OSTI ID: 21559799
• Journal Information: Journal of Chemical Physics, Vol. 131, Issue 16; Other Information: DOI: 10.1063/1.3253048; (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
DISSOCIATION
ELECTRONIC STRUCTURE
EQUATIONS OF MOTION
EXCITATION
IRRADIATION
MOLECULAR DYNAMICS METHOD
PHOSGENE
PHOTOLYSIS
POTENTIAL ENERGY
REACTION KINETICS
SELF-CONSISTENT FIELD
SIMULATION
SURFACES
SYMMETRY
THREE-BODY PROBLEM
VIBRATIONAL STATES
WAVELENGTHS
CALCULATION METHODS
CARBONIC ACID DERIVATIVES
CHEMICAL REACTIONS
DECOMPOSITION
DIFFERENTIAL EQUATIONS
ENERGY
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EQUATIONS
EXCITED STATES
KINETICS
MANY-BODY PROBLEM
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
PHOTOCHEMICAL REACTIONS