Photofragment angular dissociations

Figure 2-1. A schematic diagram of the apparatus used to record photofragment angular distributions of complexes. An F-center laser is used to pump transitions in the parent complex which leads to dissociation. A second F-center laser is used as a probe to state selectively detect the fragments. The electrodes are used to orient the parent molecules prior to excitation.

Lu Z, Oakman JE, Hu Q, Continetti RE (2008) Photoelectron-photofragment angular correlations in the dissociative photodetachment of HOCO. Mol Phys 106 595... 

Photofragment coincidence data were taken at several of the peaks in Fig. 1. Mass analysis of the fragments showed that only coincidences corresponding to channel (1), CH3 + CO (or CD3 + CO), were seen at all dissociation wavelengths examined. As discussed previously, the time and position data yield a coupled translational energy and angular distribution P(ET, 0), which can be written as... 

Levene, H.B. and Valentini, J.J. (1987). The effect of parent motion on photofragment rotational distributions Vector correlation of angular momenta and C2 symmetry breaking in dissociation of AB2 molecules, J. Chem. Phys. 87, 2594-2610. 

Figure 2-8. A pendular state (M = 0) photofragment C02-HF angular distribution corresponding to detection of the C02 fragment, showing at least three important dissociation channels. The expansion factor for the second trace is five.

Figure 24. Coincidence-imaging spectroscopy of dissociative multiphoton ionization processes in NO2 with 100-fs laser pulses at 375.3 nm, using angle-angle correlations. The polar plots show, at time delays of Ofs, 350 fs, 500 fs, 1 ps, and 10 ps, the angular correlation between the ejected electron and NO photofragment when the latter is ejected parallel to the laser field polarization vector. The intensity distributions change from a forward-backward asymmetric distribution at early times to a symmetric angular distribution at later times, yielding detailed information about the molecule as it dissociates. Taken with permission from Ref. [137]...

Photofragment spectroscopy.—The analysis of the angular distribution and energies of fragments arising from photodissociation, using polarized light, permits evaluation of the states involved in the dissociation process and an approach towards the ideal experiment in which microscopic reaction rates can be measured, and there has been much increased interest in this phenomenon in the past year, both from an experimental and theoretical standpoint. Papers... 

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