The contribution of electronically excited states to the radiation chemistry of organic systems: Progress report, June 30, 1988--April 30, 1989

Technical Report · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/5998536· OSTI ID:5998536

Lipsky, S.

The photoionization current from anthracene in liquid hydrocarbons has been studied as a function of excitation energy. From the dependence of the photocurrent spectrum on the magnitude of an externally applied electric field, it is deduced that the appearance of a fine structure in these spectra is mainly attributable, not to variability in the electron yield probability as others have conjectured, but rather to an energy dependence of the electron's thermalization range parameter. Solvent effects on the diffuseness of this structure are also explainable on this basis. By monitoring the fluorescence from hexafluorobenzene dissolved in the non-fluorescent hydrocarbon solvents, 2,3,4-trimethylpentane, 2,2-dimethylbutane, cyclopentane and tetramethylsilane excited with ..beta../sup /minus// particles, it has been possible to extract the geminate ion-pair scavenging probability, p/sup /dagger//. This is found to have a dependence on hexafluorobenzene concentration, c, entirely similar to what has previously been reported for p/sup /dagger// extracted from quenching of solvent fluorescence by perfluorocarbon scavengers. Thus it is now demonstrated that two different fluorescent techniques provide an expression for p/sup /dagger// that is distinctly disparate from that initially introduced by Warman, Asmus and Schuler to explain their results on chemical scavengers. Origins for this difference are considered. Preliminary attempts to locate a triplet-state emission from saturated hydrocarbons excited biphotonically with 307 nm XeCl excimer laser light have thus far been unsuccessful. 15 refs.

• Research Organization: Minnesota Univ., Minneapolis (USA). Dept. of Chemistry
• DOE Contract Number: FG02-85ER13404
• OSTI ID: 5998536
• Report Number(s): DOE/ER/13404-4; ON: DE89013111
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400500 -- Photochemistry
400600* -- Radiation Chemistry
ANTHRACENE
AROMATICS
CHEMISTRY
CONDENSED AROMATICS
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LEVELS
EXCITED STATES
FLUORESCENCE
HYDROCARBONS
ION PAIRS
IONIZATION
LUMINESCENCE
ORGANIC COMPOUNDS
ORGANIC SOLVENTS
PHOTOCONDUCTIVITY
PHOTOIONIZATION
PHYSICAL PROPERTIES
PROGRESS REPORT
RADIATION CHEMISTRY
RECOMBINATION
RESEARCH PROGRAMS
SCAVENGING
SOLVENTS