Theoretical Studies On The Mechanisms Of Several Important Reactions Of Radicals HC_xO(x=1,2,3) Related To The Combustion Process

Recently, the studies on the radical reactions related to combustion chemistry have been attracting the extensive attention of some scholars and scientists. The explanations and predictions of the experiments can be provided with the calculated results. In this article, the potential energy surfaces of several systems were calculated by using the quantum chemistry calculation method. The following reactions were investigated.1. The reaction of HCO . +022. The reaction of HCCO . +N023. The reaction of HCCCO . +024. The reaction of HCCCO . + NO5. The reaction of HCCCO . + N026. The reaction of HCCCO . + H207. The isomerization of SiNP systemIn the calculation, several algorithms were used, such as B3LYP/6-311G(d,p), MP2/6-311G(d,p) and CCSD(T)/6-311G(d,p) //B3LYP/ 6-31lG(d, p). The mechanisms of the reactions mentioned above were probed via analyzing the potential energy surfaces. Some rules can be drawn and used to explain the known experiments very well, and the theoretical prediction of some reactions can be givenaccording to the mechanisms.The following is the main results:1. The mechanism of reaction HCO ·+02 was investigated. By analyzing the doublet potential energy surface of the reaction, Path P,(l)and Path P2(l) leading to the main products were found, the results are as follows:Path P,(l) R-?complexl[0CH00 · ] -?P, [H02 · +C0] Path P2(l) R-Msomerl[HC(0)00 · ] -P2 [HO · +C02] Where R represents reactants HCO · +02. In Path P,(l), the H-shift is the main mechanism, and this channel is the main path at a lower pressure, and Path P2(l) is the main channel at a high pressure.2. The mechanism of reaction HCCO · +N02 was studied. By analyzing the singlet potential energy surface of the reaction, Path P,(l)and Path P2(l) leading to the main products were found, the results are as follows:Path P,(l) R-*isomerl[0N0C(H)C0 · ] -P2[NO+HCOCO · ]— P, [NO+HCO · +C0]Path P, (2) R-isomer2[HC0N0C0 · ]-~P2[N0+HC0C0 · ]— P, [NO+HCO · +C0]Where R represents reactants HCCO · +N02. The difference between the Path P,(l)and Path P2(l) is the formation of different intermediates, i.e., isomerl and isomer2. For the barrier of the reactants to isomerl is lower than that of the reactants to isomer2, the Path P,(l) is the main channel leading to P,[NO+HCO · +C0].3. The mechanism of reaction HCCCO · +02 was explored. By analyzing the doublet potential energy surface of the reaction, the main channel was found, the results are as follows:Path P, R-a3-*b3(b?) —P, [HCCO · +C02] Where R represents reactants HCCCO · +02. In this channel, b3 and b a<) —b,—P, [HCCNO ? +C0] Where R represents reactants HCCCO ? +N0.By analyzing the singlet potential energy surface of reaction HCCCO+NO2> the main channel was found, the results are as follows:Path 1 R-*isomer5 — isomer6^P,[HCCNO ? +C0] Where R represents the reactants HCCCO ? +N02. The mechanisms of reaction HCCCO ?+N0 and HCCCO ?+N02 were the formation of C2N0 four-membered ring mechanisms.5. The mechanism of reaction HCCCO ?+H20 was investigated. By analyzing the doublet potential energy surface of reaction HCCCO ? +H20, Path P, and Path P2 leading to the main products were found, the results are as follows:Path 1 R—isomerl —P,Path 1 R-?isomer3,isomer4-*isomer5, isomer6 Where R represents reactants HCCCO* +H20. The main product is the unsaturated carboxylie-acid and unsaturated 1, 3-vinylketones. In this process, the unsaturated carboxylie-acid formation goes together with the H-shift. The different 1,3-vinylketones...