Translational energy releases from photoion—photoelectron coincidence PIPECO

2 TRANSLATIONAL ENERGY RELEASES FROM PHOTOION-PHOTOELECTRON COINCIDENCE (PIPECO) 

The translational energy releases determined by PIPECO are fully covered in the tables in Sect. 8.5 the discussion here is restricted to selected decompositions. 

The mean translational energy releases in the loss of C2H2 from the molecular ion of thiophene exceed the values predicted by phase space theory by about a factor of 2 [152]. The suggestion [152] that the disagreement stems from vibrational energy not being randomised prior to dissociation seems unjustified. The loose model assumed for the transition state would seem to be the prime suspect. 

44n [310] (see Sect. 8.3). With the molecular ion of ketene losing CO [798], the slope of the mean translational energy ej vs. excess energy E — Eq line is very close to n. 

The mean translational energy releases for the formation of both (C3H3) and (C4H4)t following PI of benzene, 1, 5-hexadiyne and 2, 

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The translational energy releases reported in the literature for metastable ion decompositions are contained in Tables 1—7. Decompositions of positive ions occurring within an ion source are covered in Table 8 and decompositions of negative ions in an ion source in Table 9. Translational energy releases determined by photoion—photoelectron coincidence (PIPECO) appear, therefore, in Table 8. The results from the extensive series of electron impact (El) measurements [310] at ionizing energies close to threshold appear in Tables 8 and 9. Coverage of dissociations of diatomic ions is not exhaustive. 

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