Theoretical Study on the Reaction of Nitric Oxide with Propargyl Radical

Abstract

The reaction of nitric oxide (NO) with propargyl radical (C 3 H 3 ) was investigated at the CCSD(T)/ cc-pVTZ//B3LYP/6-311++G(df, pd) level of theory. The rate coefficients of the system were determined by using the RRKM−CVT method with Eckart tunneling correction over a temperature range of 200−800 K and a pressure range of 1.0 × 10 −4 to 10.0 bar. Eight channels proceeding via the barrierless formation of excited intermediate ONCH 2 CCH or CH 2 CCHNO at the first step were explored. Three favorable channels (i.e., channels producing adduct of ONCH 2 CCH and CH 2 CCHNO and products of HCN and H 2 CCO) were confirmed. The rate coefficients of channels producing adduct of ONCH 2 CCH and CH 2 CCHNO are comparable and have weak negative temperature dependence and positive pressure dependence. Channel producing products of HCN and H 2 CCO is more important at low pressure and high temperature and less important after pressure greater than 1.0 × 10 −2 bar (with a branching ratio less than 6% at 0.1 bar).

A kinetic study of the N(2D) + C2H4 reaction at low temperature

“…In contrast, the C3H3 + NO radical-radical reaction has been studied both experimentally 65 and theoretically. 66 The experimental investigation by DeSain et al 65 demonstrated that the measured rate constant was highly dependent on the buffer gas pressure, consistent with a termolecular reaction to form a C3H3NO adduct. The later theoretical study by Wang et al 66 indicated that bimolecular product formation should be very minor, with a branching ratio of less than 6 % predicted for the HCN + H2CCO channel at a pressure of 0.1 bar.…”

“…66 The experimental investigation by DeSain et al 65 demonstrated that the measured rate constant was highly dependent on the buffer gas pressure, consistent with a termolecular reaction to form a C3H3NO adduct. The later theoretical study by Wang et al 66 indicated that bimolecular product formation should be very minor, with a branching ratio of less than 6 % predicted for the HCN + H2CCO channel at a pressure of 0.1 bar. Consequently, neither of these processes are expected to interfere with our kinetic study of the N( 2 D) + C2H4 reaction.…”

“…DeSain et al 65 demonstrated that the measured rate constant was highly dependent on the buffer gas pressure, consistent with a termolecular reaction to form a C3H3NO adduct. The later theoretical study by Wang et al 66 indicated that bimolecular product formation should be very minor, with a branching ratio of less than 6 % predicted for the HCN + H2CCO channel at a The derived second-order rate constants and the results of earlier studies are displayed as a function of temperature in Figure 3. The values obtained during this work are also listed in T / K atoms in their investigation of N( 2 D) deactivation with several collision partners.…”

“…In contrast, the C3H3 + NO radical-radical reaction has been studied both experimentally 65 and theoretically. 66 The experimental investigation by…”

Kinetics of the Reactions of Methyl Radical with Hydrogen, Methyl and Ethyl Peroxides

“…The calculations of electronic energetics and structures were performed by the Gaussian09 program package [33] . The optimized geometries, harmonic vibrational frequencies and Zero‐point energy (ZPE) were obtained by the B3LYP, [34–36] MP2 [37] and M06‐2X [38] theories with the 6‐311++G(d,p) basis se [39] . Aug‐cc‐pVTZ basis set [40] was also used in the calculation of electronic structures to determine the effect of basis sets.…”