Contribution of electronically excited states to the radiation chemistry of organic systems. Progress report, September 1, 1978-August 31, 1979

Technical Report · Mon Jan 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/5793751· OSTI ID:5793751

Lipsky, S.

The effect of n-perfluorohexane to quench both the emission and photoionization current of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) in isooctane and in tetramethylsilane has been shown to be consistent with an interaction of perfluorohexane with some relatively long-lived, coherently excited state of TMPD that is generated at the photoionization threshold and which decays either to the emitting state of TMPD or to a geminate ion-pair. The 0/sup 0/ and 90/sup 0/ electron impact spectra of the stable isomers of C/sub 3/, C/sub 4/, and C/sub 5/ saturated hydrocarbons are being determined. Preliminary results show large structural effects on the lowest Rydberg singlet-triplet splittings. Two photon excited emission spectra of decalin, bicyclohexyl, and cyclohexane have been observed in good agreement with previously reported one-photon spectra. A weak emission from propylene has also been detected. From measurement of the photosensitized singlet emission of p-xylene by bicyclohexyl excited at 1740 A, it appears that the bicyclohexyl triplet contributes importantly to the sensitization. Also previously reported deviations from Stern-Volmer behavior in the fast-electron-excited process are found too in the photo-excited process (at 1740 A) and therefore cannot be attributed exclusively to ionic processes. The much larger ratio of excimer to monomer intensity in polystyrene as compared to neat liquid benzene appears to be due mainly to a reduced entropy of dissociation of the excimer when the phenyls are tied to the polymer backbone. Excimers formed therefore from distant phenyl groups may manifest themselves at high quencher concentrations and thus provide a new technique for probing polymer conformation.

• Research Organization: Minnesota Univ., Minneapolis (USA)
• OSTI ID: 5793751
• Report Number(s): COO-913-70
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALKANES
AMINES
BUTANE
CHEMISTRY
CYCLOALKANES
CYCLOHEXANE
DECALIN
ELECTRON SPECTRA
EMISSION SPECTRA
ENERGY LEVELS
EXCITED STATES
FLUORESCENCE
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
IONIZATION
LUMINESCENCE
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PENTANE
PHOTOIONIZATION
PROPANE
RADIATION CHEMISTRY
RESEARCH PROGRAMS
SPECTRA