Alteration of Cl spin-orbit branching ratios via photodissociation of pre-excited fundamental CH3 stretch of CH3CFCl2 Academic Article uri icon


  • Abstract The fundamental symmetric CH 3 stretch (ν 2) in the ground electronic state of CH 3 CFCl 2 is efficiently prepared by stimulated Raman excitation. The excited molecules are photodissociated by∼ 235 nm photons that further tag Cl (2 P 3/2) and Cl (2 P 1/2)[Cl*] photofragments via (2+ 1) resonantly enhanced multiphoton ionization. The yield of both photofragments increases as a result of pre-excitation, indicative of energy flow from the excited C–H to the C–Cl bond and hence a better Franck–Condon overlap between the components of the wavefunction along the C–Cl coordinate. The Cl*/Cl branching ratio is 0.60±0.09 in∼ 235 nm photolysis of vibrationally excited molecules and 0.40±0.07 in that of vibrationless ground state CH 3 CFCl 2.

publication date

  • January 1, 1999