Potential Energy Surfaces, Product Distributions and Thermal Rate Coefficients of the Reaction of O(³P) with C₂H₄(XA_g):  A Comprehensive Theoretical Study

Abstract

The potential energy surface for the O((3)P) + C(2)H(4) reaction, which plays an important role in C(2)H(4)/O(2) flames and in hydrocarbon combustion in general, was theoretically reinvestigated using various quantum chemical methods, including G3, CBS-QB3, G2M(CC,MP2), and MRCI. The energy surfaces of both the lowest-lying triplet and singlet electronic states were constructed. The primary product distribution for the multiwell multichannel reaction was then determined by RRKM statistical rate theory and weak-collision master equation analysis using the exact stochastic simulation method. Intersystem crossing of the "hot" CH(2)CH(2)O triplet adduct to the singlet surface, shown to account for about half of the products, was estimated to proceed at a rate of approximately 1.5 x 10(11) s(-1). In addition, the thermal rate coefficients k(O + C(2)H(4)) in the T = 200-2000 K range were computed using multistate transition state theory and fitted by a modified Arrhenius expression as k(T) = 1.69 x 10(-16) x T(1.66) x exp(-331 K/T) . Our computed rates and product distributions agree well with the available experimental results. Product yields are found to show a monotonic dependence on temperature. The major products (with predicted yields at T = 300 K/2000 K) are: CH(3) + CHO (48/37%), H + CH(2)CHO (40/19%), and CH(2)(X(3)B(1)) + H(2)CO (5/29%), whereas H + CH(3)CO, H(2) + H(2)CCO, and CH(4) + CO are all minor (< or =5%).

Oxidation of Ethylene—Air Mixtures at Elevated Pressures, Part 2: Chemical Kinetics

“…A third channel producing CH 2 CO (ketene) + H 2 was ascribed a 5% weighting. A recent theoretical study from Nguyen et al [23] produced a total rate constant similar to Baulch et al's recommendation but with different product ratios. The theoretical study predicts the same major products as Baulch et al, but the formation of formaldehyde and triplet methylene also becomes an important product set as the temperature increases.…”

“…While further improvement is still needed, the current version is much improved over the original one as a result of the experiments and modeling presented in Kopp et al [1] and the present paper, respectively. ... [2] ... [9] ... [4] ... [13] ... [11] ... [12] ... [16] ... [8] ... [17] ... [7] ... [14] ... [10] ... [15] ... [19] ... [5] ... [20] ... [6] ... [21] ... [1] ... [22] ... [18] ... [23] Ċ ... [34] ... [31] ... [35] ... [32] ... [36] ... [33] ... [30] ... [37] ... [26] ... [38] ... [27] ... [39] ... [28] ... [40] ... [24] ... [41] ... [25] ... [42] …”

N‐isopropylacrylamide decomposition process in helium plasma

“…Reaction (11) is also a major product found in the theoretical study 31 based on various quantum chemical methods. Peeters and Maes 32 have measured this reaction.…”

“…C 2 H 4 , and then by the O( 3 P) þ C 2 H 4 reaction. This molecule has been theoretically investigated 31 using various quantum chemical methods, and it was found that one of its major products is through the reaction channel…”

Emission spectroscopic analysis of poly(3‐octyl thiophene) exposed to plasmas

“…This is one of the major possible primary product channels with experimental reaction enthalpy (D r H(0K)) of 223 and 229 kJ/mol obtained by quantum chemical calculations. 22 • Population of HCO The HCO specie can be produced by different channels, such as R5. It has experimental D r H of 2117 kJ/mol, whereas by quantum chemical calculations the value is 2121 kJ/mol.…”