Showing papers by "Ivan Powis published in 1988"
TL;DR: In this paper, the A-band photodissociation of CH 3 I has been investigated around 280 nm, to the red of the absorption maximum, and the reduction in β for the latter is discussed in terms of the surface crossing in this channel.
85 citations
TL;DR: In this paper, a least square analysis of the spectra determined values for the band origin and the rotational constants B', D'N, DNK, and (C'−C').
Abstract: The vibrationless bands of the methyl 4p 2A‘2 ←X 2AA‘2 0–0 Rydberg transition have been recorded by mass selected (2+1) REMPI spectroscopy using photolytically generated CH3 and CD3 radicals. A least‐squares analysis of the spectra determines values for the band origin and the rotational constants B’, D’N, DNK, and (C’−C‘). Linewidths in the CH3 spectrum show a pronounced rotational level dependence and by means of a spectral simulation a heterogeneous predissociation is identified and shown to be induced by a perpendicular Coriolis coupling mechanism.
80 citations
TL;DR: In this article, mass resolved MPI spectra have been obtained for CH 3 I and CD 3 I in the region of the one-photon A-band absorption around 285 nm.
12 citations
TL;DR: In this paper, the authors investigated the methyl iodide A-band photodissociation using a photofragmenting technique coupled with state specific detection of either the iodine atom or methyl radical dissociation products by multiphoton ionization.
Abstract: The methyl iodide A-band photodissociation is investigated using a photofragment
time-of-flight technique coupled with state specific detection of either the iodine atom or
methyl radical dissociation products by multiphoton ionization. The method is quite
general and allows the fragments' velocity and spatial distributions to be determined
simultaneously with their rotational, vibrational and electronic excitation. It is shown
that methyl product from two competing dissociation channels, one direct, the other
necessitating an initial surface crossing, can be clearly distinguished by virtue of the
characteristic translational excitation in each. The different rotational excitation which
is observed in these two channels is discussed in terms of the dissociation dynamics in the
methyl iodide A-band continuum.
12 citations