Comparative pulse radiolysis studies of alkyl- and methoxy-substituted semiquinones formed from quinones and hydroquinones
作者:Vitaly A. Roginsky、Leonid M. Pisarenko、Wolf Bors、Christa Michel、Manfred Saran
DOI:10.1039/a801082j
日期:——
reduction (using CO2− as a reductant) of 1,4-benzoquinones and 1,4-naphthoquinone (Q) as well the oxidation (using N3 as an oxidant) of the corresponding hydroquinones (QH2) were determined by pulse radiolysis in 50 mM sodium phosphate buffer, pH 7.40 at room temperature. Both spectral and kinetic characteristics of Q− only moderately depended on whether Q− was produced from Q or QH2. Spectra of benzosemiquinones
吸收光谱和速率常数的12烷基和甲氧基取代的半醌阴离子自由基(Q歧化- )由单电子还原(使用CO产生2 -作为还原剂)的1,4-苯醌和1,4- -萘醌(Q)以及氧化(使用N 3室温下,在50 m M磷酸钠缓冲液(pH 7.40 )中通过脉冲辐射分解法测定相应的氢醌(QH 2)作为氧化剂。Q的光谱和动力学特征-仅适度取决于Q是否-从Q或QH产生2。苯并半醌的光谱显示出两个峰,最大峰在310–320 nm,大约为。430 nm,比率约为2–2.5。测定摩尔吸收系数。对于Q速率常数-歧化(2 ķ 1)与取代基的性质是相关的。而2 k 1几乎不受到甲基取代,Q -含异丙基,叔丁基和甲氧基的取代基均高于未取代和甲基取代的C明显更稳定- 。