氯引发的不饱和酯及酮类化合物的反应机理及动力学研究

发布时间：2018-05-17 19:33

本文选题：Cl原子 + 不饱和酯　；参考：《山东大学》2017年硕士论文

【摘要】：不饱和酯及酮类化合物都属于含氧挥发性有机化合物。环境中的不饱和酯及酮类化合物绝大部分来自人为排放。它们种类丰富,用途广泛,常作为单体或者共聚物用于聚合物的生产,如在涂料、树脂、粘合剂、薄膜、合成纤维等生产过程中被广泛应用。其结构中含有的碳碳双键与羰基直接相连,使其化学性质非常活泼,在排放进入环境后会由大气中存在的Cl原子、OH自由基、NO_3自由基和O_3分子等所引发一系列氧化降解反应,生成二次有机污染物,从而对大气的能见度和氧化能力产生影响,继而导致二次气溶胶的生成,对人类健康造成威胁。C1原子作为一种氧化剂,它所引发的不饱和挥发性有机化合物的氧化反应已备受关注。因此,由Cl原子引发的不饱和酯及酮类化合物的大气氧化过程的理论研究对于区域及全球大气化学、气候变化和环境效应等方面的研究是有重要意义的。本文采用量子化学方法对两种典型的不饱和酯类化合物--丙烯酸甲酯、丙烯酸乙酯,三种不饱和酮类化合物--3-戊烯-2-酮、4-己烯-3-酮、5-己烯-2-酮与C1原子的大气氧化反应分别进行了研究,进而对其大气氧化机理和动力学性质做了全面的了解。研究结果总结如下:1.丙烯酸甲酯与Cl原子的反应机理及动力学研究采用密度泛函理论(Density Functional Theory,DFT)在 M06-2X/6-311+G(3df,2p)//M06-2X/6-31G(d,p)水平上对由Cl原子引发的丙烯酸甲酯的氧化反应机理进行分析。由此得到了详细的反应机理:Cl加成反应、H抽提反应和CH3抽提反应三种路径。Cl加成反应在整个初级反应中占据着主要地位。因而本文对其后续反应进行研究并得到了这些反应的产物。CH3抽提反应因其反应的势垒很高而难以发生,因此该反应可以不被考虑。应用MESMER程序计算了在198-648 K的温度区间内各初级反应的速率常数。结果显示:Cl原子加成到端基碳上的反应路径更容易发生,而抽提-CH3中的H的反应也不容忽视。在298 K和760 Torr的条件下,计算所得的总包反应速率为1.66×10-10 cm3 molecule-1 s-1。在所研究的温度区间内,总包反应速率常数随温度升高反而降低,也就是说与温度呈现出负相关性。2.丙烯酸乙酯与与Cl原子的反应机理及动力学研究由C1原子所引发的丙烯酸乙酯的全面的、合理的氧化反应机理在M06-2X/6-31 1+G(3df,2p)//M06-2X/6-31G(d,p)水平上被计算得到。该反应主要包括八个反应通道:两个C1加成C=C双键的反应和六个H抽提的反应。通过比较计算结果,我们得知Cl加成到C=C双键的反应较易发生。然而,对于甲基和亚甲基上的H抽提反应也存在一定的竞争性。基于Rice-Ramsperger-Kassel-Marcus(RRKM)理论,本论文应用MESMER程序计算并得到了初级反应的速率常数。在298 K和760 Torr的条件下,计算得到的总包反应速率为1.80×10-10 cm3 molecule-1s-1。且得知在198-648 K的范围内,总的反应速率常数会与温度呈现出负相关性。此外,通过比较了 Cl原子与丙烯酸甲酯(MA)、丙烯酸乙酯、甲基丙烯酸甲酯(MMA)和烯丙基酯(AAC)的反应速率,得知它们的大小关系为kMMA(cl)kEA(cl)kMA(cl)kAAC(cl)。通过计算,得出由Cl原子引发的EA的大气寿命为154.3 h,与由其他氧化剂(如OH自由基,O_3分子和NO_3自由基)决定的EA的大其寿命相比,Cl原子引发的EA的大气氧化反应相当重要。3.不饱和酮类化合物与Cl原子的反应机理及动力学研究由C1原子引发的三种不饱和酮类化合物:3-戊烯-2-酮、4-己烯-3-酮和5-己烯-2-酮的大气氧化降解机理的研究在M06-2X/6-311+G(3df,2p)//M06-2X/6-31 G(d,p)水会平上进行的。通过计算,给出了三种不饱和酮与Cl原子完整的反应机理。反应除了 Cl-加成反应和H-抽提的反应外,本文还考虑了抽提-CH3的反应。对于前两种反应类型,Cl原子加成到碳碳双键上的反应占主导地位。其中Cl原子加成到末端碳原子上更为容易。而对于-CH3抽提反应,由于反应能垒较高且需吸收大量热量,可以被忽略。在O_2和NO存在下,论文对加成产物的后续反应进行了研究,得到了它们的主反应路径以及主产物,并进行了相应的比较。在一定的温度(198-648 K)与压力(76-2000 Torr)区间内,研究了各基元反应的速率常数与温度和压力的关系。在所研究的温度与压力范围内,速率常数呈现温度负相关性,然而随压力变化的趋势却不明显。通过计算得到了三种不饱和酮的大气寿命。
[Abstract]:Unsaturated esters and ketones belong to volatile organic compounds. Most of the unsaturated esters and ketones in the environment are derived from human emissions. They are rich in variety and widely used, often used as monomers or copolymers for the production of polymers, such as in the production process of coatings, trees, adhesives, films, synthetic fibers, etc. It is widely used. The carbon carbon double bond in its structure is directly connected with the carbonyl group to make its chemical properties very active. After the discharge into the environment, a series of oxidative degradation reactions caused by the presence of Cl atoms, OH radicals, NO_3 radicals and O_3 molecules in the atmosphere will be produced to produce two organic pollutants and thus the visibility and oxygen of the atmosphere. The influence of chemical ability, which leads to the formation of two aerosols, threatens the human health to threaten the.C1 atom as an oxidant. The oxidation of the unsaturated volatile organic compounds caused by it has been paid much attention. Therefore, the theoretical study on the atmospheric oxidation process of unsaturated esters and ketones induced by Cl atoms The study of regional and global atmospheric chemistry, climate change and environmental effects is of great significance. In this paper, the atmospheric oxygen of two typical unsaturated esters, methyl acrylate, ethyl acrylate, three unsaturated ketones, --3- amyl -2- ketone, 4- hexene -3- ketone, 5- hexene -2- ketone and C1 atom, is used in this paper. The results are summarized as follows: 1. the reaction mechanism and kinetics of methyl acrylate and Cl atom are studied by density functional theory (Density Functional Theory, DFT) at the //M06-2X/6-31G (D, P) level of M06-2X/6-311+G (3DF, 2P). The oxidation reaction mechanism of Methyl Acrylate Initiated by Cl atom is analyzed. Thus the detailed reaction mechanism is obtained: the Cl addition reaction, the H extraction reaction and the CH3 extraction reaction are the main position of the three path.Cl addition reaction in the whole primary reaction. The.CH3 extraction reaction is difficult to occur because of the high potential barrier of the reaction. Therefore, the reaction can not be considered. The rate constant of the primary reactions in the temperature range of 198-648 K is calculated by using the MESMER program. The result shows that the reaction path of the Cl atom added to the end group is easier to occur, and the reaction of the H in the extraction -CH3 is not to be ignored. Under the conditions of 298 K and 760 Torr, the calculated total package reaction rate is 1.66 * 10-10 cm3 molecule-1 s-1. in the temperature range studied. The total reaction rate constant decreases with the temperature rise. That is to say, the reaction mechanism and kinetics of the negative correlation with the temperature and the reaction mechanism and kinetics of the C1 and the Cl atom are studied by C1. The overall and reasonable oxidation reaction mechanism of Ethyl Acrylate Initiated by the atom is calculated at M06-2X/6-31 1+G (3DF, 2P) //M06-2X/6-31G (D, P) level. The reaction mainly includes eight reaction channels: two C1 addition C=C double bonds and six H extracts. However, the H extraction reaction on methyl and methylene is also competitive. Based on the Rice-Ramsperger-Kassel-Marcus (RRKM) theory, the MESMER program is used to calculate and obtain the rate constant of the primary reaction. The total reaction rate of the total package is 1.80 * 10-1 under the 298 K and 760 Torr strips. 0 cm3 molecule-1s-1. and in the range of 198-648 K, the total reaction rate constant will have a negative correlation with the temperature. In addition, by comparing the reaction rates of Cl atoms with methyl acrylate (MA), ethyl acrylate, methyl methacrylate (MMA) and allyl ester (AAC), they know that their size relation is kMMA (CL) kEA (CL) kMA. C (CL). By calculation, the atmospheric lifetime of EA caused by Cl atoms is 154.3 h, compared with the lifetime of EA determined by other oxidants such as OH free radicals, O_3 molecules and NO_3 free radicals. The EA atmospheric oxidation reaction initiated by Cl atoms is very important for the reaction mechanism and kinetics of the.3. unsaturated ketones with the atoms. Three kinds of unsaturated ketones induced by atoms: the atmospheric oxidation degradation mechanism of 3- amyl -2- ketone, 4- hexene -3- ketone and 5- hexene -2- ketone is carried out on the M06-2X/6-311+G (3DF, 2P) //M06-2X/6-31 G (D,). The reaction mechanism of the three unsaturated ketones with the atom is given. In addition to the reaction of H- extraction, this paper also considers the reaction of extracting -CH3. For the first two types of reaction, the reaction of Cl atoms added to carbon carbon double bonds is dominant. The addition of Cl atoms to the end carbon atoms is easier. For the -CH3 extraction reaction, the reaction energy barrier is high and the absorption of a large amount of heat can be ignored. In O_2 and N In the presence of O, the subsequent reactions of the added products were studied, and their main reaction paths and main products were obtained, and the corresponding comparisons were made. The relationship between the constant number of reaction rates of the basic elements and the temperature and pressure was studied at a certain temperature (198-648 K) and pressure (76-2000 Torr). The temperature and pressure studied were studied. In the range, the rate constant presents a negative correlation with temperature, but the trend of pressure variation is not obvious. The atmospheric lifetime of three unsaturated ketones is calculated.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.12

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