Pulse radiolysis of 2,4,5-trichlorophenol: Formation, kinetics, and properties of hydroxytrichlorocyclohexadienyl, trichlorophenoxyl, and dihydroxytrichlorocyclohexadienyl radicals

Journal Article · Thu Mar 09 04:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100342a048· OSTI ID:7071537

Draper, R B; Fox, M A ^[1]; Pelizzetti, E ^[2]; Serpone, N ^[3]

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1. Univ. of Texas, Austin (USA)
2. Universita di Torino (Italy)
3. Concordia Univ., Montreal, Quebec (Canada)

Pulse radiolysis has been used to optically and kinetically characterize the transient free radicals formed by the reaction of H{sup {sm bullet}}, N{sub 3}{sup {sm bullet}}, or OH{sup {sm bullet}} with 2,4,5-trichlorophenol (TCP-OH). The hydroxy-2,4,5-trichlorocyclohexadienyl radical (H-TCP-OH) formed by H{sup {sm bullet}} addition to TCP-OH (k = (1.1 {plus minus} 0.2) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}) has an absorption maximum at 360 nm with {epsilon}{sub 360} = (4700 {plus minus} 1000) M{sup {minus}1} cm{sup {minus}1}. The 2,4,5-trichlorophenoxyl radical (TCP-O{sup {sm bullet}}) formed by the reaction of N{sub 3}{sup {sm bullet}} with TCP-O- (k = (4.3 {plus minus} 0.8) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}) has an absorption maximum at 430 nm with {epsilon}{sub 430} = (3600 {plus minus} 600) M{sup {minus}1} cm{sup {minus}1}. The dihydroxy-2,4,5-trichlorocyclohexadienyl radical (HO-TCP-OH) formed by OH{sup {sm bullet}} radical addition to TCP-OH (k = (1.2 {plus minus} 0.1) {times} 10{sup 10} M{sup {minus}1} s{sup {minus}1}) has an absorption maximum at 320 nm with {epsilon}{sub 320} = (5300 {plus minus} 250) M{sup {minus}1} cm{sup {minus}1}. The principal isomer formed by the reaction of OH{sup {sm bullet}} with TCP-OH is the 1,6-dihydroxy-2,4,5-trichlorocyclohexadienyl radical, which has a pK{sub a} of 4.8 {plus minus} 1.0. The solution absorption from each radical decays via second-order kinetics on the millisecond time scale.

• OSTI ID: 7071537
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:5; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
AROMATICS
BEAMS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISTRY
CHLORINATED AROMATIC HYDROCARBONS
DECOMPOSITION
ELECTRON BEAMS
ENERGY RANGE
HALOGENATED AROMATIC HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
IRRADIATION
KINETICS
LEPTON BEAMS
MEV RANGE
MEV RANGE 01-10
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
PARTICLE BEAMS
PHENOL
PHENOLS
PHENOXY RADICALS
PHYSICAL PROPERTIES
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
REACTION KINETICS
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
WATER
YIELDS