Studies of the Fragment-ion Distribution and Reaction with a Charge Spectrometer. VI. A New Interpretation of the Fragmentation Mechanism in CH3X Based on the Molecular Orbital Method. (2)

Abstract

Abstract We have proposed a new fragmentation mechanism and successfully applied it to various monosubstituted alkanes RX. The fragmentation mechanism can be described as follows: (1) The bond scission first occurs where the electrons exist densely in the particular occupied molecular orbital correlated to the particular ionization. (2) Process (1) competes with the electron redistribution. (3) In the higher-energy region, secondary scission also occurs. The breakdown curves of the CH3NH2+, CH3SH+, and CH3Br+ produced by charge-exchange reactions have been obtained by the use of a perpendicular double-mass spectrometer. The experimental results can be satisfactorily explained by the proposed mechanism on the basis of the calculated eigenvectors of the various molecular orbitals.