Dynamics of rotational energy release for dissociation of singlet ketene and the singlet/triplet branching ratio

Journal Article · Thu Jan 23 04:00:00 EST 1997 · Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory

DOI:https://doi.org/10.1021/jp962131l· OSTI ID:502006

Wade, E A; Clauberg, H; Kim, S K; Mellinger, A; Moore, C B ^[1]

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1. Lawrence Berkeley National Lab., CA (United States)

The rotational energy release in the dissociation of ketene along its singlet potential energy surface is observed and compared with various statistical and dynamical theories. Rotational distributions for CO(XO{sup 1}{Sigma}{sup +})({upsilon}=1) are measured from the threshold for production of CH{sub 2}(aO{sup 1}A{sub 1})(0,0,0) + CO(XO{sup 1}{Sigma}{sup +})({upsilon}=1) to 1720 cm{sup -1} above. At low energies (<200 cm{sup -1}), phase space theory (PST) matches the observed distributions. At 357 and 490 cm{sup -1}, PST, constrained by the measured state distributions of the methylene fragment, provides a good fit. For E > 1107 cm{sup -1}, the constrained PST matches the average rotational energy observed but gives distributions which are broader than observed. This contrasts with the {sup 1}CH{sub 2} fragment rotations which become progressively colder than PST as energy increases from 200 cm{sup -1} above the threshold. The CO({upsilon}=1) rotational distributions for E > 357 cm{sup -1} contain no measurable product from triplet channel fragmentation. They can be compared with the previously determined CO(v=0) rotational distributions in order to partition the yield between singlet and triplet channels and recalculate the singlet yield. This yield is found to be at the upper limit of the range previously reported. 32 refs., 10 figs., 2 tabs.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 502006
• Journal Information: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory Journal Issue: 4 Vol. 101; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
99 GENERAL AND MISCELLANEOUS
BOLTZMANN STATISTICS
BRANCHING RATIO
CHEMICAL REACTION KINETICS
DISSOCIATION
KETENES
MOLECULES
NUMERICAL DATA
PHASE SPACE
POTENTIAL ENERGY
ROTATIONAL STATES