scholarly journals Theoretical Study of C2H5 + NCO Reaction: Mechanism and Kinetics

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Nan-Nan Wu ◽  
Shun-li OuYang ◽  
Liang Li
Keyword(s):  
Low Temperatures ◽  
High Pressures ◽  
Theoretical Study ◽  
Single Point ◽  
Structure Information ◽  
Theoretical Investigations ◽  
Mechanism And Kinetics ◽  
Combustion Processes ◽  
Low Pressures ◽  
Kinetics Of

Theoretical investigations are performed on mechanism and kinetics of the reactions of ethyl radical C2H5 with NCO radical. The electronic structure information of the PES is obtained at the B3LYP/6-311++G(d,p) level of theory, and the single-point energies are refined by the CCSD(T)/6-311+G(3df,2p) level of theory. The rate constants for various product channels of the reaction in the temperature range of 200–2000 K are predicted by performing VTST and RRKM calculations. The calculated results show that both the N and O atoms of the NCO radical can attack the C atom of C2H5 via a barrierless addition mechanism to form two energy-rich intermediates IM1 C2H5NCO (89.1 kcal/mol) and IM2 C2H5OCN (64.7 kcal/mol) on the singlet PES. Then they both dissociate to produce bimolecular products P1 C2H4 + HOCN and P2 C2H4 + HNCO. At high temperatures or low pressures, the reaction channel leading to bimolecular product P2 is dominant and the channel leading to P1 is the secondary, while, at low temperatures and high pressures, the collisional stabilization of the intermediate plays an important role and as a result IM2 becomes the primary product. The present results will enrich our understanding of the chemistry of the NCO radical in combustion processes.

scholarly journals Theoretical Study of the C2H5 + HO2 Reaction: Mechanism and Kinetics

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1919
Author(s):  
Nan-Nan Wu ◽  
Ming-Zhe Zhang ◽  
Shun-Li Ou-Yang ◽  
Liang Li
Keyword(s):  
High Pressures ◽  
Single Point ◽  
State Theory ◽  
Major Product ◽  
Measured Temperature ◽  
Structure Information ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Ho2 Radical ◽  
Good Agreement

The mechanism and kinetics for the reaction of the HO2 radical with the ethyl (C2H5) radical have been investigated theoretically. The electronic structure information of the potential energy surface (PES) is obtained at the MP2/6-311++G(d,p) level of theory, and the single-point energies are refined by the CCSD(T)/6-311+G(3df,2p) level of theory. The kinetics of the reaction with multiple channels have been studied by applying variational transition-state theory (VTST) and Rice–Ramsperger–Kassel–Marcus (RRKM) theory over wide temperature and pressure ranges (T = 220–3000 K; P = 1 × 10−4–100 bar). The calculated results show that the HO2 radical can attack C2H5 via a barrierless addition mechanism to form the energy-rich intermediate IM1 C2H5OOH (68.7 kcal/mol) on the singlet PES. The collisional stabilization intermediate IM1 is the predominant product of the reaction at high pressures and low temperatures, while the bimolecular product P1 C2H5O + OH becomes the primary product at lower pressures or higher temperatures. At the experimentally measured temperature 293 K and in the whole pressure range, the reaction yields P1 as major product, which is in good agreement with experiment results, and the branching ratios are predicted to change from 0.96 at 1 × 10−4 bar to 0.66 at 100 bar. Moreover, the direct H-abstraction product P16 C2H6 + 3O2 on the triplet PES is the secondary feasible product with a yield of 0.04 at the collisional limit of 293 K. The present results will be useful to gain deeper insight into the understanding of the kinetics of the C2H5 + HO2 reaction under atmospheric and practical combustion conditions.

THE THERMAL DECOMPOSITION OF ETHANE: PART III. SECONDARY REACTIONS

1966 ◽  
Vol 44 (20) ◽  
pp. 2369-2380 ◽  
Author(s):  
M. C. Lin ◽  
M. H. Back
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
High Pressures ◽  
Thermal Dissociation ◽  
First Order ◽  
Butyl Radical ◽  
Secondary Reactions ◽  
Low Pressures ◽  
Kinetics Of ◽  
Subsequent Decomposition

The kinetics of the secondary reactions producing methane, butane, and butene-1 in the pyrolysis of ethane have been investigated over the temperature range 550–726 °C and at pressures from 600–10 mm. The rate of secondary methane production was second order in ethylene at high pressures but was first order in ethylene at low pressures and high temperatures. In the latter region it is concluded that isomerization of the n-butyl radical to sec-butyl with subsequent decomposition to CH3 + C3H6 was the main source of methane. The rate of butane formation increased with time at low temperatures and decreased with time at high temperatures. It is shown that the decrease in rate was mainly due to the thermal dissociation of butane. The main source of butene-1 was probably decomposition of the n-butyl radical.

A Theoretical Study of the Mechanism and Kinetics of F+N3 Reactions

ChemPhysChem ◽  
2006 ◽  
Vol 7 (8) ◽  
pp. 1786-1794 ◽  
Author(s):  
Haitao Ma ◽  
Xiaojun Liu ◽  
Wensheng Bian ◽  
Lingpeng Meng ◽  
Shijun Zheng
Keyword(s):  
Theoretical Study ◽  
Mechanism And Kinetics ◽  
Kinetics Of

scholarly journals The thermal decomposition of acetaldehyde and the existence of different activated states

1933 ◽  
Vol 141 (843) ◽  
pp. 41-55 ◽  
Keyword(s):  
High Pressures ◽  
Initial Pressure ◽  
Bimolecular Reaction ◽  
Bimolecular Reactions ◽  
First Order ◽  
Straight Line ◽  
Gas Reactions ◽  
Pass Through ◽  
Low Pressures ◽  
Kinetics Of

Homogeneous thermal gas reactions were at one time tacitly assumed to possess a definite order, unimolecular and bimolecular reactions, for example, being sharply distinguished. The kinetics of the decomposition of acetalde­ hyde, CH 3 CHO = CH 4 + CO, over the pressure range of 100 to 400 mm. were found to satisfy the criterion of a bimolecular reaction, namely, that the reciprocal of the time for half change (1/ t 1/2 ) )plotted against the initial pressure ( p 0 ) gave a straight line inclined to the axes. The line, however, did not pass through the origin, as may be seen in fig. 1 of the present paper. This indicated the presence of some first order reaction, the nature of which was not determined. Subsequently, in accordance with the collision theory of activation and deactivation, it was shown that certain reactions, sometimes called quasiummolecular, change their order from the second at low pressures to the first at high pressures. This apparently was the reverse of the behaviour shown by acetaldehyde.

scholarly journals The effect of thermal agitaion on atomic arrangement in alloys—II

1935 ◽  
Vol 151 (874) ◽  
pp. 540-566 ◽  
Keyword(s):  
High Temperatures ◽  
Experimental Work ◽  
Low Temperatures ◽  
Theoretical Treatment ◽  
X Ray ◽  
Atomic Arrangement ◽  
Metal Atoms ◽  
Theoretical Investigations ◽  
The Subject ◽  
Kinetics Of

The transformations between a disordered arrangement of the metal atoms in an alloy at high temperatures and an ordered arrangement of the atoms at low temperatures have formed the subject of many experimental and theoretical investigations. The process of segregation into regular positions was first envisaged by Tammann in 1919. It was proved to take place in the gold-copper and other alloy systems by Johannson and Linde by X-ray investigation. Theoretical treatments of the problem have been given in papers by Borelius, Johannson, and Linde, Gorsky, and Dehlinger and Graf, and the same authors have published a large amount of experimental work on this type of transformation in the Au-Cu system. Some experiments on order-disorder transformations in the Fe-Al system, carried out by Bradley and Jay in this laboratory, led us to examine the kinetics of the change, and we recently published a paper in these Proceedings dealing with various aspects of it. Since publishing this paper, we have become aware that our theoretical treatment has in several respects a closer parallelism to those of Borelius, Gorsky, and Dehlinger than we realized at the time of writing it. We shall try to make a proper acknowledgment in the present paper.

Theoretical Study of Mechanism and Kinetics of the Reaction of NO2with s-Triazine

2016 ◽  
Vol 41 (6) ◽  
pp. 987-993
Author(s):  
Ji-Dong Zhang ◽  
Li-Hua Kang ◽  
Xin-Lu Cheng
Keyword(s):  
Theoretical Study ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Theoretical Study on the Reaction Mechanism and Kinetics of Criegee Intermediate CH2OO with Acrolein

2018 ◽  
Vol 122 (44) ◽  
pp. 8729-8737 ◽  
Author(s):  
Cuihong Sun ◽  
Shaoyan Zhang ◽  
Junyong Yue ◽  
Shaowen Zhang
Keyword(s):  
Reaction Mechanism ◽  
Theoretical Study ◽  
Mechanism And Kinetics ◽  
Kinetics Of
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