Electron affinities of aromatic hydrocarbons and disproportionation of their radical-anions

Conference · Mon Sep 01 04:00:00 EDT 1986 · Am. Chem. Soc., Div. Pet. Chem., Gen. Pap., Prepr.; (United States)

OSTI ID:6867890

Szwarc, M

Electron affinities of aromatic hydrocarbons measured in the gas-phase and in solutions are compared. The experimental methods used for their determination are briefly reviewed. The reduction yields the respective radical-anions. Radical-anions may undergo disproportionation, a reaction described by the scheme: 2A/sup -/ . , Cat/sup =/ in equilibrium A + A/sup 2-/, 2 Cat/sup +/, K/sub dipr/. The disproportionation constant, K/sub dipr/, is greatly affected by the nature of aromatic hydrocarbon, of the cation, and of the solvent. Variation of each of these factors is illustrated. Variation of the cation and solvent results in changes of the disproportionation constant as large as factors of 10/sup 25/. The causes of these variations are rationalized and discussed in terms of the respective ..delta..H and ..delta..S. Kinetics of disproportionation was investigated by flash-photolysis techniques. The experimental approach is described. The peculiarities of Ba salts deserved some discussion to clarify the nature of those salts. The effect of disproportionation on reactions of radical-anions are described: namely on cis-trans isomerization of stilbenes, on protonation of radical-anions of anthracene an perylene, on dissociation of radical anions of aromatic derivatives ethane, etc.

• Research Organization: Dept. of Chemistry, UCSD LaJolla, CA 92093
• OSTI ID: 6867890
• Report Number(s): CONF-860911-
• Conference Information: Journal Name: Am. Chem. Soc., Div. Pet. Chem., Gen. Pap., Prepr.; (United States) Journal Volume: 31:3
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALINE EARTH METAL COMPOUNDS
ALKANES
ANIONS
ANTHRACENE
AROMATICS
BARIUM CHLORIDES
BARIUM COMPOUNDS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CONDENSED AROMATICS
DECOMPOSITION
DERIVATIZATION
DISSOCIATION
DOCUMENT TYPES
ELECTRONIC STRUCTURE
ETHANE
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
IONS
ISOMERIZATION
KINETICS
MEASURING METHODS
ORGANIC COMPOUNDS
PERYLENE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
REACTION KINETICS
REDUCTION
REVIEWS
SOLVENTS
STILBENE
STRUCTURAL CHEMICAL ANALYSIS
YIELDS