Transition state and barrier height for the silanediyl insertion reaction SiH2+ H2? SiH4

1983 ◽  
pp. 785 ◽  
Author(s):  
Roger S. Grev ◽  
Henry F. Schaefer
Keyword(s):  
Transition State ◽  
Barrier Height ◽  
Insertion Reaction

Allowed and Forbidden Reaction Paths for the H2 + D2 Exchange Reaction

1975 ◽  
Vol 53 (4) ◽  
pp. 549-555 ◽  
Author(s):  
James S. Wright
Keyword(s):  
Transition Metal ◽  
Transition State ◽  
Exchange Reaction ◽  
Barrier Height ◽  
Dissociation Energy ◽  
Basis Set ◽  
Reaction Paths ◽  
Double Zeta ◽  
Double Zeta Basis

Symmetry arguments and abinitio s.c.f. calculations (double-zeta basis set) are used to show that the exchange reaction H2+ D2 → 2HD could proceed in a concerted fashion through a six-center transition state. The computed barrier height of 90 kcal/mol for this process lies below the experimental dissociation energy of H2 (but above the computed dissociation energy) and also below the energy required for exchange through a four-center transition state. Either the termolecular(2 + 2 + 2 ) or bimolecular(4 + 2 ) cycloadditions are thermally allowed. The presence of a transition metal would allow the reaction to proceed through a four-center geometry, leading to the formation of a possibly stable metal-H4 complex.

The reaction of aluminum atoms with methane

1990 ◽  
Vol 68 (4) ◽  
pp. 633-639 ◽  
Author(s):  
Hengtai Yu ◽  
John D. Goddard
Keyword(s):  
Transition State ◽  
Energy Barrier ◽  
Energy Requirement ◽  
Basis Sets ◽  
Insertion Reaction ◽  
Reaction Coordinates ◽  
Abstraction Reaction ◽  
Level Transition ◽  
Split Valence ◽  
Good Agreement

Abinitio SCF and CISD calculations with split valence and larger basis sets have been carried out for several possible reactions of ground state (2P) aluminum atoms with methane. In particular, the barriers to insertion of Al into a CH bond to give a CH3AlH intermediate and the abstraction of a hydrogen by Al to give AlH and CH3 have been studied. At the SCF level, transition state structures have been located and verified by vibrational analyses. In addition, intrinsic reaction coordinates (IRC) have been followed from the transition state geometries down to reactants and to products. Calculated vibrational frequencies and lowest excitation energy for the CH3AlH intermediate are in good agreement with matrix isolation experimental results. As anticipated on the basis of MO natural correlation symmetry arguments, the energy barrier to the insertion reaction is high (~50 kcal mol−1 at the CI level). The energy requirement for the abstraction reaction is similar.[Formula: see text]Keywords: Al, CH4, HAlCH3, insertion and abstraction reactions.

State-Resolved Reactivity of CH4(2ν3) on Pt(111) and Ni(111):  Effects of Barrier Height and Transition State Location†

2007 ◽  
Vol 111 (49) ◽  
pp. 12679-12683 ◽  
Author(s):  
R. Bisson ◽  
M. Sacchi ◽  
T. T. Dang ◽  
B. Yoder ◽  
P. Maroni ◽  
...  
Keyword(s):  
Transition State ◽  
Barrier Height

Transition state structure, barrier height, and vibrational frequencies for the reaction Cl+CH4→CH3+HCl

1989 ◽  
Vol 90 (12) ◽  
pp. 7137-7142 ◽  
Author(s):  
Thanh N. Truong ◽  
Donald G. Truhlar ◽  
Kim K. Baldridge ◽  
Mark S. Gordon ◽  
Rozeanne Steckler
Keyword(s):  
Transition State ◽  
Barrier Height ◽  
Vibrational Frequencies ◽  
State Structure ◽  
Transition State Structure
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