Decomposition of multifunctionalized α-alkoxyalkyl-hydroperoxides derived from the reactions of Criegee intermediates with diols in liquid phases
Decomposition of multifunctionalized α-alkoxyalkyl-hydroperoxides derived from the reactions of Criegee intermediates with diols in liquid phases
复制标题
DOI：
10.1039/d2cp00915c
复制
发表时间：
2022-04-27
影响因子：
3.3
通讯作者：
Enami, Shinichi
中科院分区：
文献类型：
--
作者：
Endo, Yasuyuki;Sakamoto, Yosuke;Enami, Shinichi
挥发性有机化合物在大气中的氧化产生有机氢过氧化物（ROOH），其通常不仅具有-OOH，而且具有其他官能团，例如-OH和-C（=O）。由于它们的高亲水性和低挥发性，这种多官能化ROOH预计将被吸收在大气冷凝相中，如气溶胶和雾/云滴。然而，ROOH的特点，控制其命运和寿命在液相中知之甚少。在这里，我们报告的多官能化的α-烷氧基烷基氢过氧化物（α-AHs），具有醚，羰基，氢过氧化物，和两个羟基的液相分解动力学的研究。这些ROOH通过在1，3-丙二醇、1，4-丁二醇或1，5-戊二醇存在下在水中臭氧分解α-萜品醇来合成。它们的分解产物被检测为氯离子加合物，通过电喷雾质谱作为反应时间的函数。使用（H2O）-O-18和D2 O的实验表明，半缩醛物种是α-AH的分解产物，其进一步转化为其他产物。C-15 α-AHs的分解速率系数（k）从pH 5.0到3.9呈指数增加的结果与H+催化分解机理一致。k的温度依赖性和Arrhenius图得出的α-氢化物分解的活化能（E-a）分别为15.7 +/- 0.8、15.0 +/- 2.4和15.9 +/- 0.3 kcal mol（-1），这些氢化物来自α-松油醇CI与1，3-丙二醇、1，4-丁二醇和1，5-戊二醇的反应。将测定的E-a值与相关ROOH值进行比较。我们发现，烷基链的长度是不是一个关键因素的分解机制，而额外的-OH基团的存在下，将通过与周围的水分子形成氢键调节分解的反应障碍。衍生的E-a值的分解的多功能，萜类衍生的α-AH将有助于大气建模作为代表性的值ROOH在大气冷凝相。
The oxidation of volatile organic compounds in the atmosphere produces organic hydroperoxides (ROOHs) that typically possess not only -OOH but also other functionalities such as -OH and -C(=O). Because of their high hydrophilicity and low volatility, such multifunctionalized ROOHs are expected to be taken up in atmospheric condensed phases such as aerosols and fog/cloud droplets. However, the characteristics of ROOHs that control their fates and lifetimes in liquid phases are poorly understood. Here, we report a study of the liquid-phase decomposition kinetics of multifunctionalized alpha-alkoxyalkyl-hydroperoxides (alpha-AHs) that possessed an ether, a carbonyl, a hydroperoxide, and two hydroxy groups. These ROOHs were synthesized by ozonolysis of alpha-terpineol in water in the presence of 1,3-propanediol, 1,4-butanediol, or 1,5-pentanediol. Their decomposition products were detected as chloride anion adducts by electrospray mass spectrometry as a function of reaction time. Experiments using (H2O)-O-18 and D2O revealed that hemiacetal species were alpha-AH decomposition products that further transformed into other products. The result that the rate coefficients (k) of the decomposition of C-15 alpha-AHs increased exponentially from pH 5.0 to 3.9 was consistent with an H+-catalyzed decomposition mechanism. The temperature dependence of k and an Arrhenius plot yielded activation energies (E-a) of 15.7 +/- 0.8, 15.0 +/- 2.4, and 15.9 +/- 0.3 kcal mol(-1) for the decomposition of alpha-AHs derived from the reaction of alpha-terpineol CIs with 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol, respectively. The determined E-a values were compared with those of related ROOHs. We found that alkyl chain length is not a critical factor for the decomposition mechanism, whereas the presence of additional -OH groups would modulate the reaction barriers to decomposition via the formation of hydrogen-bonding with surrounding water molecules. The derived E-a values for the decomposition of the multifunctionalized, terpenoid-derived alpha-AHs will facilitate atmospheric modeling by serving as representative values for ROOHs in atmospheric condensed phases.