Mechanism of reaction of SO/sub 4//sup -/ with some derivatives of benzoic acid

Journal Article · Thu Dec 14 04:00:00 EST 1978 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100514a008· OSTI ID:6315281

Zemel, H; Fessenden, R W

The products of the reactions of SO/sub 4//sup -/ with some benzoic acid derivatives have been examined by ESR using steady-state radiolysis and photolysis to produce SO/sub 4//sup -/ and by optical absorption spectrophotometry in pulse radiolysis experiments. The optical absorption spectrum of the hydroxycyclohexadienyl radical following reaction of benzene with SO/sub 4//sup -/ is shown to be formed with <0.1 ..mu..s delay. Thus it appears that a cation is formed which reacts very rapidly with water. Similarly, pulse ESR methods have been used to show that the p-carboxyphenyl radical is formed within <1 ..mu..s of the reaction of SO/sub 4//sup -/ with terephthalate. With benzoate, most of the reaction leads to the phenyl radical but about 30% gives hydroxycyclohexadienyl radicals. The three isomeric toluates give different products. The ortho isomer gives mainly the o-carboxybenzyl radical while the para isomer gives approximately equal amounts of p-carboxybenzyl, p-methylphenyl, and a mixture of hydroxycyclohexadienyl radicals. The meta isomer gives mainly a mixture of hydroxycyclohexadienyl radical isomers. Several carboxyphenols were studied by ESR and all gave phenoxyl radicals. All reactions observed are consistent with the oxidation of the benzene ring to a cationic species which then reacts in parallel reactions by either hydroxylation, loss of a proton (from OH or CH/sub 3/ groups), or loss of CO/sub 2/.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA
• OSTI ID: 6315281
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 82:25; ISSN JPCHA
• 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
ABSORPTION SPECTROSCOPY
AROMATICS
BENZENE
BENZOIC ACID
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DICARBOXYLIC ACIDS
ELECTRON SPIN RESONANCE
ESTERS
HYDROCARBONS
MAGNETIC RESONANCE
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
RESONANCE
SPECTROSCOPY
SULFATES
SULFUR COMPOUNDS
TEREPHTHALIC ACID