Ab initio calculations of activation energy of the reaction of hydrogen exchange on strongly acidic centers

1999 ◽  
Vol 48 (8) ◽  
pp. 1431-1435
Author(s):  
Yu. A. Borisov ◽  
Yu. A. Zolotarev
Keyword(s):  
Activation Energy ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Hydrogen Exchange

scholarly journals Theoretical studies on the intramolecular cyclization of 2,4,6-t-Bu3C6H2P=C: and effects of conjugation between the P=C and aromatic moieties

2014 ◽  
Vol 10 ◽  
pp. 1032-1036 ◽  
Author(s):  
Masaaki Yoshifuji ◽  
Shigekazu Ito
Keyword(s):  
Activation Energy ◽  
Dft Calculations ◽  
Physicochemical Properties ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Intramolecular Cyclization ◽  
Theoretical Studies ◽  
Cyclization Product ◽  
No Activation

The intramolecular C–H insertion of the Mes*-substituted phosphanylidenecarbene [Mes*P=C:] (Mes* = 2,4,6-t-Bu3C6H2) and physicochemical properties of the cyclized product, 6,8-di-tert-butyl-3,4-dihydro-4,4-dimethyl-1-phosphanaphthalene were studied based on ab initio calculations. Whereas the alternative Fritsch–Buttenberg–Wiechell-type rearrangement requires almost no activation energy, the intramolecular cyclization needs an activation energy of 12.3 kcal/mol at the MP2(full)/6-31G(d) condition. DFT calculations supported that the optimized structure of the cyclization product of Mes*P=C: suggests remarkable conjugation effects between the nearly coplanar P=C skeleton and the aryl moiety.

Ab initio calculations of the quantum mechanical hydrogen exchange coupling in the [(C5H5)Ir(PH3)H3]+ complex

1993 ◽  
Vol 115 (13) ◽  
pp. 5861-5862 ◽  
Author(s):  
Abdellah Jarid ◽  
Miquel Moreno ◽  
Agusti Lledos ◽  
Jose M. Lluch ◽  
Juan Bertran
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Exchange Coupling ◽  
Hydrogen Exchange ◽  
Quantum Mechanical

A theoretical study on the bimolecular hydrogen exchange aminonitrene → trans-diimide. Comparison with formaldehyde photochemistry

1981 ◽  
Vol 59 (21) ◽  
pp. 3044-3048 ◽  
Author(s):  
M. J. H. Kemper ◽  
H. M. Buck
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Hydrogen Exchange ◽  
Theoretical Study ◽  
Experimental Studies ◽  
Activation Energies ◽  
Stabilization Energy ◽  
The Other ◽  
Hydrogen Shift

Ab initio calculations on the rearrangement aminonitrene → trans-diimide are reported. It is shown that a bimolecular hydrogen exchange is much easier than a unimolecular 1,2 hydrogen shift: the reactions have activation energies of 4 and 94 kcal/mol, respectively. The hydrogen exchange starts from dimers which have a fairly large stabilization energy. Infrared and Raman frequencies of these dimers are calculated in order to facilitate experimental studies. Some striking similarities are indicated between diimide chemistry and the photochemistry of formaldehyde. It is shown that results from one field are transferable to the other one. From this, some new experiments are suggested.

Concentration-Dependence of Self-Interstitial and Boron Diffusion in Silicon

2008 ◽  
Vol 1070 ◽  
Author(s):  
Wolfgang Windl
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Ab Initio Calculations ◽  
Fermi Level ◽  
Total Energy ◽  
Ab Initio ◽  
The Self ◽  
Recent Experimental Data ◽  
Boron Diffusion ◽  
Experimental Values

ABSTRACTIn this paper, we discuss the accuracy of ab-initio calculations for self-interstitial and boron dif-fusion in silicon in light of recent experimental data by de Salvador et al. and Bracht et al. Map-ping the experimental data onto the activation energy vs. Fermi level representation commonly used to display ab-initio results, we show that the experimental results are consistent with each other. While the theoretical LDA value for the boron activation energy as a function of the Fermi level agrees well with experiment, we find for the self-interstitial in line with other calculations an underestimation of the experimental values, despite using total-energy corrections.

Ab Initio Calculations for Hydrocarbons:  Enthalpy of Formation, Transition State Geometry, and Activation Energy for Radical Reactions

2003 ◽  
Vol 107 (43) ◽  
pp. 9147-9159 ◽  
Author(s):  
Mark Saeys ◽  
Marie-Françoise Reyniers ◽  
Guy B. Marin ◽  
Veronique Van Speybroeck ◽  
Michel Waroquier
Keyword(s):  
Activation Energy ◽  
Transition State ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Enthalpy Of Formation ◽  
Radical Reactions ◽  
Transition State Geometry

Millimetre-wave and infrared spectroscopy of Br13 CN: anharmonic force field of cyanogen bromide from spectroscopic data and ab initio calculations

1997 ◽  
Vol 90 (3) ◽  
pp. 495-497
Author(s):  
CLAUDIO ESPOSTI ◽  
FILIPPO TAMASSIA ◽  
CRISTINA PUZZARINI ◽  
RICCARDO TARRONI ◽  
ZDENEK ZELINGER
Keyword(s):  
Infrared Spectroscopy ◽  
Force Field ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spectroscopic Data ◽  
Cyanogen Bromide ◽  
Millimetre Wave ◽  
Anharmonic Force
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