Ones, at E c = 31.4 kJ/mol, being six isomeric These findings were corroboratedīy the theory, which predicts a variety of competing product channels,įollowing N( 2D) addition to the double bond, with the main Experimentally, no evidence of CN, HCN, and N 2 forming channels was observed. Of a variety of possible C 3H 2N 2 isomeric Recorded for the H-displacement channels leading to the formation Product angular and TOF distributions have been Possible via a submerged barrier, leading ultimately to N 2 + C 3H 3 formation, the most exothermic of all In competition, the N( 2D) addition to the CN group is also Of N( 2D) to the carbon–carbon double bond of CH 2=CH–CN, followed by the formation of cyclicĪnd linear intermediates that can undergo H, CN, and HCN elimination. According to our theoreticalĬalculations, the reaction is found to proceed via barrierless addition Stratosphere and at a total energy corresponding to the E c of the CMB experiment. The one corresponding to the temperature (175 K) of Titan’s PES have been carried out at different values of temperature, including RRKM) calculations of product branching fractions (BFs) on the theoretical Statistical (Rice–Ramsperger–Kassel–Marcus, The doublet potential energy surface (PES) have been performed toĪssist in the interpretation of the experimental results and characterize Synergistic electronic structure calculations of (TOF) analysis at the collision energy, E c, of 31.4 kJ/mol. Scattering method with mass spectrometric detection and time-of-flight Under single-collision conditions by the crossed molecular beam (CMB) N( 2D), with vinyl cyanide, CH 2CHCN, has been The reaction of electronically excited nitrogen atoms, Overall, the results are expected to have a significant impact on the gas-phase chemistry of Titan's atmosphere and should be properly included in the photochemical models. The above cyclic and linear products containing an additional C-N bond could be potential precursors of more complex, N-rich organic molecules that contribute to the formation of the aerosols on Titan's upper atmosphere.
The predicted product BFs are found to have, in general, a very weak energy dependence. The highly exothermic N2 + CH2CCH (propargyl) channel is also predicted to be negligible because of the very high isomerization barrier from the initial addition intermediate to the precursor intermediate able to lead to products. These findings were corroborated by the theory, which predicts a variety of competing product channels, following N(2D) addition to the double bond, with the main ones, at Ec = 31.4 kJ/mol, being six isomeric H forming channels: c-CH(N)CHCN + H (BF = 35.0%), c-CHNCHCN + H (BF = 28.1%), CH2NCCN + H (BF = 26.3%), c-CH2(N)CCN(cyano-azirine) + H (BF = 7.4%), trans-HNCCHCN + H (BF = 1.6%), and cis-HNCCHCN + H (BF = 1.3%), while C-C bond breaking channels leading to c-CH2(N)CH(2H-azirine) + CN and c-CH2(N)C + HCN are predicted to be negligible (0.02% and 0.2%, respectively). Experimentally, no evidence of CN, HCN, and N2 forming channels was observed. Product angular and TOF distributions have been recorded for the H-displacement channels leading to the formation of a variety of possible C3H2N2 isomeric products. In competition, the N(2D) addition to the CN group is also possible via a submerged barrier, leading ultimately to N2 + C3H3 formation, the most exothermic of all possible channels. According to our theoretical calculations, the reaction is found to proceed via barrierless addition of N(2D) to the carbon-carbon double bond of CH2═CH-CN, followed by the formation of cyclic and linear intermediates that can undergo H, CN, and HCN elimination. Statistical (Rice-Ramsperger-Kassel-Marcus, RRKM) calculations of product branching fractions (BFs) on the theoretical PES have been carried out at different values of temperature, including the one corresponding to the temperature (175 K) of Titan's stratosphere and at a total energy corresponding to the Ec of the CMB experiment. Synergistic electronic structure calculations of the doublet potential energy surface (PES) have been performed to assist in the interpretation of the experimental results and characterize the overall reaction micromechanism. The reaction of electronically excited nitrogen atoms, N(2D), with vinyl cyanide, CH2CHCN, has been investigated under single-collision conditions by the crossed molecular beam (CMB) scattering method with mass spectrometric detection and time-of-flight (TOF) analysis at the collision energy, Ec, of 31.4 kJ/mol.
0 kommentar(er)
