Volume 123, Issue 2, 08 July 2005
Index of content:
Quasiperiodic trajectories in the unimolecular dissociation of ethyl radicals by time-frequency analysis123(2005); http://dx.doi.org/10.1063/1.1950673View Description Hide Description
Direct classical trajectory calculations for ethyl radical, , at the HCTH147@ level of theory support the experimental observation that the dissociation of highly excited ethyl radicals to ethylene and and a hydrogen atom can occur much more slowly than predicted by statistical rate theories. Only 78% of the trajectories of ethyl radicals prepared in a microcanonical ensemble with excitation energy above the zero-point energy and zero total angular momentum dissociate to form . The remaining hot ground-state ethyl radicals have a lifetime of , during which a time-frequency analysis finds them trapped for extended periods of time in long-lived quasiperiodic trajectories.
A systematic shift in the electronic spectra of substituted benzene molecules trapped in helium nanodroplets123(2005); http://dx.doi.org/10.1063/1.1988309View Description Hide Description
Electronic spectra have been recorded from five separate substituted benzene derivatives trapped in heliumnanodroplets. Each member of the series is found to exhibit a blueshift with respect to the equivalent transition in the gas phase. Taken together with previous results for benzene, the observed shifts show a remarkably good correlation with changes in electron density that occur within each of the aromatic rings as a result of electronic excitation.