Photodissociation dynamics of CH3CFCl2 and CDCl3 at 205–209nm

Near-threshold photodissociation dynamics of CHCl3

“…The latter value corresponds to 46% of excess energy being channelled into translation which is in excellent agreement with the work by Huber and co-workers who determined this value to be 43% using photofragment translational spectroscopy. 36 The two-photon fragment energies as measured by Kawasaki and co-workers extend to much higher energies, 37 further enforcing our conclusion that the results presented here are due to single-photon excitation.…”

“…Kawasaki and co-workers measured an anisotropy parameter of around 0.3 for Cl at the slightly longer wavelength of 205 nm, but no value for Cl* was reported, 37 while Bersohn and co-workers measured an almost isotropic angular distribution for both spin-orbit states. 21 However, the geometry of chloroform with the C-Cl bond not being parallel to the main axis of symmetry already limits the anisotropy parameters to values in the narrow range between 1/3 and À2/3.…”

“…The dissociation dynamics of chloroform have so far been identified as being dominated by the 1 Q 1 state, 37 or as involving the two excited states 1 Q 1 and 3 Q 0 . 36 The 3 Q 0 state is the only state to correlate with spin-orbit excited chlorine atoms, but it is identifiable as it is also the only state involving a parallel transition.…”

“…17 The only other measurement of the anisotropy parameter b was performed by Kawasaki and co-workers, albeit for CDCl 3 at the slightly longer wavelength range between 205 and 209 nm. 37 Their measurements indicate a perpendicular transition with anisotropy parameters (reported for Cl( 2 P 3/2 ) only) increasing from around 0.3 at low kinetic energies up to 0.7 at high kinetic energies.…”

“…21 In the slightly longer wavelength range from 205 to 209 nm, Kawasaki and co-workers measured a chlorine kinetic energy distribution after CDCl 3 dissociation using the VMI technique which is rather broad and extends past 2.7 eV, showing that some two-photon processes take place. 37 They fitted their distribution to the sum of a Gaussian (centred at 1.39 eV) and a Maxwell-Boltzmann distribution (with a temperature of 7000 K) in a ratio of 40 : 60. Most importantly, their kinetic energy distribution stretches from >4 eV all the way to 0 eV (and shows some population at low energies), while the distributions by Huber and co-workers 36 and Matsumi et al 21 gradually decline towards low kinetic energies.…”