The CH + N2 Association Reaction at Low Temperatures: Ab Initio MO/VRRKM-Theory Analysis of Temperature and Pressure Effects

Abstract

Microcanonical Variational RRKM / Rate Constants / Pressure EffectThe microcanonical variational RRKM formalism combined with high level ab initio and density functional calculations has been applied to the reaction of CH( 2 Π) with molecular nitrogen at low and moderate temperatures. The existing experimental T , P-dependent data for T < 1000 K could be theoretically accounted for. Our simulations reproduced very well the strong negative temperature and strong positive pressure effects observed experimentally. The comparison with less rigorous variational techniques demonstrates the importance of the microscopic rate constant minimization at the E and J resolved level.

The story of NCN as a key species in prompt-NO formation

“…Similar to Berman and Lin [21] and later Moskaleva and Lin [23], the authors concluded that collisional stabilization of HCN 2 is dominant at low temperatures whereas dissociation of this adduct becomes important at higher temperatures. Similar theoretical analyses were performed at about the same time by Rodgers and Smith [24] and Miller and Walch [25].…”

Kinetics of the Removal of OH(v = 1) and OD(v = 1) by HNO3 and DNO3 from 253 to 383 K

“…Herbert et al observed that the removal of CH( v = 1) by N 2 is rapid [ k (294 K) = 3.0 × 10 -11 cm 3 molecule -1 s -1 ] and that the rate coefficient for this process shows a moderate negative temperature dependence between 86 and 584 K: when fit to expression II, n was ∼1.2. They attribute the fast removal of CH( v = 1) by N 2 to the formation of the weakly-bound CHN 2 species: the strength of the dative bond between CH and N 2 is approximately 30 kcal mol -1 . Herbert et al suggest that the CHN 2 complex might dissociate before the CH vibrational excitation energy is redistributed to the other modes of the complex.…”