Department of Chemistry, Faculty of Science, Islamic Azad University, Shahr-e-Qods Branch, Tehran, Iran.
J Hazard Mater. 2010 Feb 15;174(1-3):801-6. doi: 10.1016/j.jhazmat.2009.09.123. Epub 2009 Sep 30.
Conversion of catechols to corresponding nitro derivatives in the presence of nitrous acid dissociation is studied using voltammetry and UV-vis spectrophotometry. The results indicate that the quinones derived from oxidation of catechols by nitrous acid participate in Michael addition reaction with nitrite ion in very mild acidic solutions. Rank annihilation factor analysis RAFA is applied to resolve the two-way kinetic spectra data measured from spectroscopic reactions. The rank of the original data matrix is reduced by one by annihilating the information of each component. It is shown that both reactions are drastically depends on pH and nitrous acid or nitrite ion percentage. The rate constants of oxidation and nitration reactions of catechol derivatives are obtained at the pHs around pK(a) of nitrous acid.
使用伏安法和紫外可见分光光度法研究了亚硝酸解离存在下儿茶酚转化为相应硝基衍生物的反应。结果表明，亚硝酸氧化儿茶酚生成的醌在非常温和的酸性溶液中与亚硝酸根离子发生迈克尔加成反应。秩消去因子分析 RAFA 被应用于解析从光谱反应中测量的双向动力学谱数据。通过消去每个组分的信息，将原始数据矩阵的秩降低 1。结果表明，这两个反应都强烈依赖于 pH 值以及亚硝酸或亚硝酸根离子的百分比。在亚硝酸的 pK(a) 左右的 pH 值下，获得了儿茶酚衍生物的氧化和硝化反应的速率常数。
