ISSN:
0951-4198
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
Coincidence techniques have been used to investigate double photoionization and subsequent decay of a series of polycyclic aromatic hydrocarbons (PAHs) from benzene to perylene. At fixed photon energy (40.8eV) the total yield of double ionization relative to single photoionization for both PAHs and for aliphatic compounds increases asthe same function of the excess energy above the double ionization energy. The ratio of double to single ionization for a given compound at different photon energies varies linearly with the excess energy. The fraction of dissociative double photoionization falls with increasing size in the PAH series; the ejection of characteristic neutral species (H·, H2 and C2H2) is the main dissociation pathway in the larger PAHs while charge separation is important for smaller species. Partial hydrogenation or aliphatic substitution results in decreasing stability of the doubly charged ions and increasing dissociation.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/rcm.1290051106