function of pH. E17 of the radicals is equal to E27 of the parent and is –15 mV. The two-electron reduction potential of naphthazarin is –62 mV at pH 7 and –351 mV at pH 0. The optical absorption spectra of 1,4,5,8-tetrahydroxynaphthalene prepared in different ionised forms by radiolysis and by chemical reduction have been determined. The redox data and the absorption spectra show that this compound has
观察到由
萘达那林单电子还原形成的自由基的歧化与pH在1-14范围内的函数关系。自由基最不容易在pH 8–9时歧化,在pH约为ca时稳定常数。8.5为0.4。将数据与
萘他
沙林的单电子还原电势相结合以获得自由基的单电子还原电势(即母体的第二单电子还原电势)随pH的变化。自由基的E 1 7等于E 2 7母端的电压为–15 mV。
萘他林的双电子还原电位在pH 7时为–62 mV,在pH 0时为–351 mV。通过电离和
化学还原以不同电离形式制备的1,4,5,8-四羟基
萘的光吸收光谱已被测定。决心。氧化还原数据和吸收光谱表明,该化合物具有的p K a值为7.6和8.7,并且没有进一步的p K a值低于ca。14。