Contribution of electronically excited states to the radiation chemistry of organic systems. Progress report, September 1, 1980-November 30, 1981

Technical Report · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5508611

Lipsky, S

The effect of a perfluorocarbon to quench the photoionization current of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) in a non-polar liquid has been studied as a function of temperature, excitation energy and the nature and composition of the solution. A model is developed to explain the results on the basis of an interaction of the quencher with an epithermal electron. Contact charge-transfer bands involving saturated hydrocarbons and perfluorocycloalkanes have been discovered. Similar bands are not observed for hydrocarbon contact with perfluoro-n-alkanes. Also, perfluorocycloalkanes are found to have very strong quenching effect on saturated hydrocarbon fluorescence. Analysis of the quenching behavior indicates unusually large (approx. = 14 A) encounter radii for this quenching interaction. A long-range charge transfer appears to be implicated. The fluorescence quantum yield of liquid cyclohexane has been determined for excitation wavelengths from 165 nm to 178 nm. This data together with new measurements on the intensity of fluorescence of cyclohexane liquid excited by /sup 85/Kr beta particles confirms that G(S/sub 1/) = 1.45. The ratio of excimer to monomer fluorescence of dilute solutions of polystyrene in various solvents has been observed to increase with increasing polymer molecular weight and decreasing thermodynamic quality of the solvent. The effects are demonstrated to be not attributable to excimer formation via non-adjacent sites.

• Research Organization: Minnesota Univ., Minneapolis (USA)
• OSTI ID: 5508611
• Report Number(s): DOE/ER/00913-2; ON: DE82004906
• 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
ALKANES
AMINES
CHEMISTRY
CYCLOALKANES
CYCLOHEXANE
ENERGY LEVELS
EXCITED STATES
FLUORESCENCE
FLUORINATED ALICYCLIC HYDROCARBONS
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALICYCLIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
IONIZATION
LUMINESCENCE
MATERIALS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
ORGANIC SOLVENTS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHOTOIONIZATION
PLASTICS
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
RADIATION CHEMISTRY
RESEARCH PROGRAMS
SCINTILLATION QUENCHING
SOLVENTS
SYNTHETIC MATERIALS
TEMPERATURE EFFECTS