Translational spectroscopy

Ashfold M N R, Mordaunt D H and WIson S H S 1996 Photodissociation dynamics of hydride molecules H atom photofragment translational spectroscopy Adv. Photochem. 21 217-95... 

Translational spectroscopy. A technique to investigate the distribution of the velocities of product ions from ion/neutral reactions. 

J. Helpburn, Photofragment translational spectroscopy, Atomic and Molecular Beam Methods, ed. G. Scoles (Cambridge Press). 

A. M. Wodtke and Y. T. Lee, High resolution photofragmentation - Translational spectroscopy , in Molecular Photodissociation Dynamics, eds. M. N. R. Ashfold and J. E. Baggott, Royal Society of Chemistry, London, 1987. 

The photodissociation dynamics of jet-cooled methyl radical produced in a pyrolysis radical beam have been investigated at 193.3 nm using photofragment translational spectroscopy by North and co-workers.112 Only... 

Photodissociation Dynamics of Hydride Molecules H Atom Photofragment Translational Spectroscopy (Ashfold, Mordaunt, and Wilson) Photo-Fries Rearrangement and Related Photochemical (l.j) Shifts of... 

While one might expect that the techniques developed for photodissociation studies of closed-shell molecules would be readily adaptable to free radicals, this is not the case. A successful photodissociation experiment often requires a very clean source for the radical of interest in order to minimize background problems associated with photodissociating other species in the experiment. Thus, molecular beam photofragment translation spectroscopy, which has been applied to innumerable closed-shell species, has been used successfully on only a handful of free radicals. With this problem in mind, we have developed a conceptually different experiment [4] in which a fast beam of radicals is generated by laser photodetachment of mass-selected negative ions. The radicals are photodissociated with a second laser, and the fragments are detected in coinci-... 

Even the homolytic dissociation of a very simple molecule reveals an unexpected wealth of information in time-of-flight translational spectroscopy. The molecule S02 undergoes dissociation when excited with far UV light (193 nm)... 

X.M. Yang, State-to-state dynamics of elementary chemical reactions using Rydberg translational spectroscopy, Int. Rev. Phys. Chem. 24, 37 (2005). 

The qualitative picture suggested by these calculations has recently been confirmed by new experiments on the UV photochemistry of phenol. Lee and collaborators have shown that loss of H atoms is the major process in phenol at 248 nm excitation [36], Ashfold and co-workers have applied high-resolution photofragment translational spectroscopy to obtain uniquely detailed insight into the photodissociation dynamics of phenol [37], The phenoxy radical is produced in a surprisingly limited subset of its available vibrational states [37], Such vibrational mode-specific dynamics is a signature of ultrafast radiationless decay through directly accessible conical intersections. Similar results have been obtained for pyrrole, imidazole and indole [38 10],... 

The UV photochemistry of phenol and related systems (such as indole, pyrrole, imidazole) is dominated by a hydrogen detachment reaction which is driven by repulsive 1ira states [33,35 10], For the isolated chromophores, the 1 mr -driven photodissociation has been explored in unprecedented detail by high-resolution photofragment translational spectroscopy [40], The OH (or NH) bond is broken homolytically, resulting in the formation of two radical species, the hydrogen atom and the phenoxy (or indolyl, etc.) radical. Ion pair formation (abstraction of protons) is energetically not feasible for isolated photoacids. 

The FIK experiment is essentially translational spectroscopy. The reactant ion M+ is formed, preferably in free space, at a potential V0 and decomposes in a strong electric field [41, 223], If the potential at the point of decomposition is, the translational energy of a product ion m+ on reaching a region at ground potential is... 

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