Infrared Multiphoton Photochemistry of Vinylcyclopropane. Variation of Yield and Branching Ratio with Experimental Parameters

Article abstract of DOI:10.1021/ja00404a006

The infrared photochemistry of vinylcyclopropane has been comprehensively investigated.Irradiation of vinylcyclopropane at relatively low pressures with the partially focused output of a CO2 laser leads to a mixture of the C5 products cyclopentene, cyclopentadiene, 1,4-pentadiene, and cis- and trans-1,3-pentadiene.The composition of the product mixture as well as the total product yields are a sensitive function of experimental parameters.The effects of bath gas pressure, laser power, laser intensity, laser frequency, and number of pulses have been systematically examined.A simple physical picture of the multiphoton activation and resulting decomposition is developed.RRKM theory is employed to calculate energy-dependent unimolecular reaction rates.The model is quite successful in rationalizing these data, providing good evidence for the qualitative validity of a rate equation description of infrared multiphoton dissociation.