Departamento de Ingeniería Química y Química Física, Facultad de Ciencias, and Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad, (IACYS), Universidad de Extremadura, Avenida de Elvas s/n, 06006 Badajoz, Spain.
Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, and Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad, (IACYS), Universidad de Extremadura, Avenida de Elvas s/n, 06006 Badajoz, Spain.
J Phys Chem A. 2023 Feb 16;127(6):1491-1498. doi: 10.1021/acs.jpca.2c08091. Epub 2023 Feb 7.
Gas-phase and aqueous oxidations of formic and oxalic acids with ozone and OH radicals have been thoroughly examined by DFT methods. Such acids are not only important feedstocks for the iterative construction of other organic compounds but also final products generated by mineralization and advanced oxidation of higher organics. Our computational simulation unravels both common and distinctive reaction channels, albeit consistent with known H atom abstraction pathways and formation of hydropolyoxide derivatives. Notably, reactions with neutral ozone and OH radical proceed through low-energy concerted mechanisms involving asynchronous transition structures. For formic acid, carbonylic H-abstraction appears to be more favorable than the dissociative abstraction of the acid proton. Formation of long oxygen chains does not cause a significant energy penalty and highly oxygenated products are stable enough, even if subsequent decomposition releases environmentally benign side substances like O and HO.
通过 DFT 方法，深入研究了气相和水相中甲酸和草酸与臭氧和 OH 自由基的氧化反应。这些酸不仅是其他有机化合物迭代构建的重要原料，也是更高有机物矿化和高级氧化生成的最终产物。我们的计算模拟揭示了共同和独特的反应通道，尽管与已知的 H 原子提取途径和水合聚氧衍生物的形成一致。值得注意的是，与中性臭氧和 OH 自由基的反应通过涉及异步过渡结构的低能协同机制进行。对于甲酸，羰基 H 提取似乎比酸质子的离解提取更有利。形成长氧链不会导致显著的能量损失，并且高度氧化的产物足够稳定，即使随后的分解释放出环境友好的侧物质，如 O 和 HO。
