Anisotropic photodissociation of CH3Cl+center dot

Photodissociation of the methyl chloride ion has been investigated using ma ss-analyzed ion kinetic spectrometry (MIKES). The MIKE spectrum for the chl orine atom loss from the methyl chloride ion has been measured as a functio n of the laser polarization angle at 357, 488.0, and 514.5 nm. The anisotro py parameters and kinetic energy release distributions have been determined . At all the wavelengths used, an anisotropic dissociation (beta = 1.2) in the repulsive excited electronic state has been observed. Results from quan tum chemical calculations carried out at the various levels suggest that th e methyl chloride ion is excited to the first excited electronic state (A) over tilde, and dissociates repulsively in this state. (C) 2001 American In stitute of Physics.