Hyperthermal Dynamics and Kinetics of the C(³P) + N₂(X¹Σg+) → CN(X²Σ+) + N(⁴S) Reaction

Abstract

The hyperthermal dynamics and kinetics of the title reaction, which plays an important role in hypersonic chemistry for atmospheric entry vehicles, are investigated using quasi-classical trajectory methods on a recently developed ground electronic state potential energy surface. The dynamics calculations indicated that the reaction follows a complex-forming mechanism, despite its large endoergicity. The calculated differential cross section is forward–backward symmetric, consistent with a long-lived reaction intermediate supported by the NCN potential well. The lifetime of the reaction complex is sufficiently long that the vibrational distribution of the CN product can be predicted by the phase space theory. The calculated vibrational state specific and thermal rate coefficients follow the Arrhenius behavior, and the agreement with existing low-temperature experimental thermal rate coefficients is satisfactory. Extrapolations to high temperatures relevant to hypersonic conditions are provided.

Quantum and semiclassical studies of nonadiabatic electronic transitions between N(4S) and N(2D) by collisions with N2

“…Such exchange channels are known to be efficient in hyperthermal collisions. [49][50][51][52] In our calculations reported here, (R2) is either implicitly included in the WP calculations, through the use of a damping term, or explicitly included in the CSDM calculations. As shown in this work, the adiabatic exchange channel (R2b) has much larger rate coefficients than the nonadiabatic channels (R-1 and (R2a)).…”

Quantum and Semiclassical Dynamics of Nonadiabatic Electronic Excitation of C(3P) to C1D) by Hyperthermal Collisions with N2

“…We note in passing that the collision between C and N 2 might lead to the following reaction as well normalC ( P 3 ) + normalN 2 → CN ( X 2 Σ + ) + normalN ( S 4 ) ; 0.25em normalΔ H 0 = 2.04 0.25em eV The 3 A″ potential energy surface (PES) for this highly endoergic reaction has been investigated in the past. − The excited state C( 1 D) also reacts with N 2 , but the global singlet PES for the excited-state reaction has not been mapped out. In this work, we do not consider these reactive channels.…”