Dissociation of cyclohexene and 1,4-cyclohexadiene in a molecular beam

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.456841· OSTI ID:5573417

Zhao, X; Continetti, R E; Yokoyama, A; Hintsa, E J; Lee, Y T ^[1]

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1. Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory and Department of Chemistry, University of California, Berkeley, California 94720 (US)

Molecular-beam photofragmentation translational spectroscopy of cyclohexene and 1,4-cyclohexadiene was carried out using 193 nm and IR multiphoton excitation. At 193 nm, both the retro-Diels--Alder reaction of cyclohexene and H{sub 2} elimination from both molecules were observed in the ground electronic state, indicating the occurrence of internal conversion from the initially excited electronic states. The retro-Diels--Alder reaction is shown to be concerted up to an internal energy higher than 148 kcal/mol. Hydrogen-atom elimination was also observed for both molecules following 193 nm excitation. The H atom is eliminated from an excited state of cyclohexene and is assigned to be from a carbon adjacent to the double bond, with a corresponding C--H bond energy of 87{plus minus}3 kcal/mol. It is shown that the peak of the translational energy distribution for concerted dissociation in the ground state is determined mainly by the dynamics of the potential-energy release along the reaction coordinate, and is not sensitive to either the amount of internal energy or the form of excitation.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5573417
• Journal Information: Journal of Chemical Physics; (USA), Vol. 91:7; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CYCLOALKENES
PHOTOLYSIS
DIENES
DISSOCIATION
FAR ULTRAVIOLET RADIATION
MOLECULAR BEAMS
MULTI-PHOTON PROCESSES
ALKENES
BEAMS
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
HYDROCARBONS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
POLYENES
RADIATIONS
ULTRAVIOLET RADIATION
400500* - Photochemistry