174736-01-7Relevant academic research and scientific papers
Lifetime, reduction potential and base-induced fragmentation of the veratryl alcohol radical cation in aqueous solution. Pulse radiolysis studies on a ligninase "Mediator"
Bietti, Massimo,Baciocchi, Enrico,Steenken, Steen
, p. 7337 - 7342 (1998)
The radical cation of veratryl alcohol (3,4-dimethoxybenzyl alcohol), VA?+, was produced in aqueous solution, mainly by oxidation with the radiation chemically generated SO4?- or Tl2+. By electron-transfer equilibration with thioanisole as a redox standard, the reduction potential of VA?+ was determined to be 1.36 ± 0.01 V/NHE. On the basis of product analysis results, the radical cation undergoes a C - H deprotonation reaction from the side chain, leading to an α-hydroxybenzyl-type radical, with k = (17 ± 1) s-1 at pH ≤ 5, as determined by time-resolved conductance. The α-hydroxybenzyl-type radical was also produced by reduction of veratryl aldehyde with the hydrated electron, and the pKa value of this radical was determined to be 10.0. The deprotonation of VA?+ is enhanced by bases such as OH-, with the rate constant being 1.3 × 109 M-1 s-1. In contrast, the corresponding rate constant for reaction of OH with the radical cation of veratryl alcohol methyl ether, whose reduction potential is also 1.36 V/NHE, is only 2 × 107 M-1 s-1. With the veratryl alcohol derivative, 3,4-(MeO)2C6H3CH(OH)CMe3, the radical cation undergoes both a proton loss from the benzylic position and a Cα-Cβ fragmentation with the ratio, at pH ≤ 5, of ca. 1:2. The decay of the radical cation is strongly enhanced by OH (k = 8.3 × 109 M-1 s-1), with the base induction favoring the C-C fragmentation relative to the proton loss from the benzylic position. The possible bearing of these results with respect to the role of VA in the lignin peroxidase-catalyzed decomposition of lignin is discussed.
Kinetic study of the hydrogen abstraction reaction of the benzotriazole-N-oxyl radical (BTNO) with H-donor substrates
Brandi, Paolo,Galli, Carlo,Gentili, Patrizia
, p. 9521 - 9528 (2007/10/03)
The aminoxyl radical (>N-O.) BTNO (benzotriazole-N-oxyl) has been generated by the oxidation of 1-hydroxybenzotriazole (HBT; >N-OH) with a CeIV salt in MeCN. BTNO presents a broad absorption band with λmax 474 nm and e 184
