The Kinetics of the Reaction C₂H₅ ^• + HI → C₂H₆ + I^• over an Extended Temperature Range (213–623 K): Experiment and Modeling

Abstract

The present study reports temperature dependent rate constantsHighly correlated

Detailed benchmark ab initio mapping of the potential energy surfaces of the X + C2H6 [X = F, Cl, Br, I] reactions

“…Comparing our new benchmark data to previous results 14,16,17,22,25,[28][29][30]33,35,[37][38][39][40][41] of the literature, where only the main H-abstraction channel was investigated for the X + C 2 H 6 [X = F, Cl, Br, I] reactions, we find considerable inaccuracies regarding the barrier heights, even their signs for X = F and Cl.…”

“…reported CCSD/cc-pVDZ structures along with spin-orbit corrections for the stationary points of this reaction. 41 In the present study we extend the investigations of the halogen + ethane reactions towards new, so far unstudied mechanisms, such as H-substitution and methyl-substitution. We also consider the Walden-inversion and front-side-attack pathways for both substitution channels.…”

“…Besides the main H-abstraction reaction path and the higher-energy H-substitution studied also for halogen + methane reactions, in the X + C 2 H 6 [F, Cl, Br, I] reactive system methyl-substitution appears as a new mechanism and is expected to occur at lower energies then H-substitution. For these reactions so far only the H-abstraction channel (X = F, Cl) [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] or its reverse reaction (X = Br, I) [34][35][36][37][38][39][40][41] have been investigated.…”

“…the HX + C 2 H 5 -X + C 2 H 6 reactions have been the subject of both theoretical and experimental investigations due to their supposedly non-Arrhenius behavior. [34][35][36][37][38][39][40][41] For the HBr + C 2 H 5 -Br + C 2 H 6 reaction theoretical studies using the CCSD(T)/cc-pVTZ method as highest level of theory revealed a loosely-bound adduct in the entrance channel and a tightly-bound TS very close in energy and both being below the reactant asymptote. 35,38,39 The HI + C 2 H 5 -I + C 2 H 6 reaction has also been studied both by experimental 34,40 and theoretical 40,41 techniques.…”

Automated full-dimensional potential energy surface development and quasi-classical dynamics for the HI(X1Σ+) + C2H5 → I(2P3/2) + C2H6 reaction

“…As a class of elementary reactions, atom transfer or metathesis reactions of HX + C 2 H 5 ↔ X + C 2 H 6 (X = F, Cl, Br, I) have become benchmark systems to study the dynamics and mechanisms of post-six-atom polyatomic chemical reactions. These exothermic reactions have attracted a lot of attention from both experiment and theory for the forward processes (X = Br, I) 1–9 and backward processes (X = F, Cl), 10–34 whose activation energies have been found to have small positive or negative values. 35…”