标题： 关于在活性氧和氯物种存在下2-乙基己基4-甲氧基肉桂酸酯光降解的实验和理论研究 显示英文标题

标题： Experimental and theoretical studies on the photodegradation of 2-ethylhexyl 4-methoxycinnamate in the presence of reactive oxygen and chlorine species

摘要： 2-乙基己基4-甲氧基肉桂酸酯（EHMC）是最常用的防晒成分之一。 本研究调查了EHMC在存在过氧化氢（H2O2）、盐酸（HCl）、紫外光（UV）等常见氧化和氯化系统下的光降解情况。 反应产物通过气相色谱质谱联用仪（GC-MS）检测。 实验研究表明，氯取代的4-甲氧基肉桂酸（4-MCA）、4-甲氧基苯甲醛（4-MBA）和4-甲氧基苯酚（4-MP）被鉴定出来。 实验研究通过密度泛函理论（DFT）和MP2计算进行了补充。 我们发现，4-MCA、4-MBA和4-MP与Cl2和HOCl的反应在所有情况下都具有热力学优势。 然而，反应性指数提供了更好的关于特定氯代有机化合物形成的解释。 通常，那些单氯化和双氯化化合物中具有最高硬度的异构形式被确定。 通过福井函数考察了氯代有机化合物前体的亲核性。 显示英文摘要

摘要： 2-Ethylhexyl 4-methoxycinnamate (EHMC) is one of the most commonly used sunscreen ingredient. In this study we investigated photodegradation of EHMC in the presence of such common oxidizing and chlorinating systems as H2O2, H2O2/HCl, H2O2/UV, and H2O2/HCl/UV. Reaction products were detected by gas chromatography with a mass spectrometric detector (GC-MS). As a result of experimental studies chloro-substituted 4-methoxycinnamic acid (4-MCA), 4-methoxybenzaldehyde (4-MBA) and 4-methoxyphenol (4-MP) were identified. Experimental studies were enriched with DFT and MP2 calculations. We found that reactions of 4-MCA, 4-MBA and 4-MP with Cl2 and HOCl were in all cases thermodynamically favorable. However, reactivity indices provide a better explanation of the formation of particular chloroorganic compounds. Generally, those isomeric forms of mono- and dichlorinated compounds which exhibits the highest hardness were identified. Nucleophilicity of the chloroorganic compounds precursors were examined by means of the Fukui function.