Structured Electron Transfer Transition State. Valence Bond Configuration Mixing Analysis and ab Initio Calculations of the Reactions of Formaldehyde Radical Anion with Methyl Chloride

1996 ◽  
Vol 100 (30) ◽  
pp. 12241-12252 ◽  
Author(s):  
G. Narahari Sastry ◽  
Sason Shaik
Keyword(s):  
Electron Transfer ◽  
Transition State ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Radical Anion ◽  
Valence Bond ◽  
Methyl Chloride ◽  
Configuration Mixing

Nitro–Nitrite Isomerization and Transition State Switching in the Dissociation of Ionized Nitromethane: A Threshold Photoelectron–Photoion Coincidence Spectroscopy Study

2009 ◽  
Vol 15 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Brandon Ferrier ◽  
Anne-Marie Boulanger ◽  
David M.P. Holland ◽  
David A. Shaw ◽  
Paul M. Mayer
Keyword(s):  
Transition State ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Bond Cleavage ◽  
Cleavage Reaction ◽  
Nitrite Ion ◽  
Methyl Nitrite ◽  
Bond Cleavage Reaction ◽  
Entropy Of Activation ◽  
Lower Entropy

Threshold photoelectron–photoion coincidence (TPEPICO) spectroscopy has been employed to investigate the competition between bond cleavage and rearrangement reactions in the dissociation of ionized nitromethane, 1. Modeling TPEPICO breakdown diagrams with a combination of RRKM theory and ab initio calculations at the G3 level of theory allowed the derivation of the activation energy for the isomerisation of 1 to ionized methyl nitrite, 2, 82 kJ mol−1. In addition, evidence was found for a transition state switch in the bond cleavage reaction in 1 leading to CH3• + NO2+. As internal energy increases, the effective transition state for this reaction becomes tighter (i.e. is characterized by a lower entropy of activation, Δ‡S). Fitted thresholds for NO+ and CH2OHO+ ions, originating from the isomeric methyl nitrite ion, are consistent with G3 level ab initio calculations.

Ab initio MO studies on the potential energy surface of the methyl chloride radical anion

1992 ◽  
Vol 114 (5) ◽  
pp. 1593-1595 ◽  
Author(s):  
Tsukasa Tada ◽  
Reiko Yoshimura
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Radical Anion ◽  
Energy Surface ◽  
Methyl Chloride ◽  
Ab Initio Mo

Vibrational Spectra of Dipyrido[3,2-a:2′,3′-c]phenazine and Its Radical Anion Analyzed by Ab Initio Calculations and Deuteration Studies

2002 ◽  
Vol 75 (5) ◽  
pp. 933-942 ◽  
Author(s):  
Benjamin James Matthewson ◽  
Amar Flood ◽  
Matthew Ian James Polson ◽  
Christopher Armstrong ◽  
David Lee Phillips ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Vibrational Spectra ◽  
Radical Anion

scholarly journals Conformational study on the structures and energies of the weakly bound complexes of AlCl3 with diatomic molecules

2007 ◽  
Vol 5 (4) ◽  
pp. 1007-1018 ◽  
Author(s):  
Issac Jimenez-Fabian ◽  
Abraham Jalbout ◽  
Abderahim Boutalib
Keyword(s):  
Transition State ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Conformational Study ◽  
Weakly Bound ◽  
Hydrogen Halides ◽  
Strength Of Interaction ◽  
Weakly Bound Complexes ◽  
Aluminium Trichloride ◽  
High Level

AbstractIn this work we present the results of high level ab initio calculations on weakly bound complexes of aluminium trichloride and hydrogen halides, HX, halogens, X2 and diatomic interhalogens, XY (where X, Y = F, Cl, Br). Based upon these calculations we have predicted that all structures in the staggered conformation (except for Cl3AlFH and Cl3AlClH) are stable minima while those in the eclipsed configurations are transition state structures. In the XH complexes the strength of interaction with the Cl3Al group is FH > ClH > BrH. In the case of X2 species it is Br2 > F2 > Cl2, and finally in the XY (YX) group it is: FBr > ClBr > FCl > BrCl > BrF > ClF.

A study of hydrogen abstraction reactions by halogen atoms with HFCO and HClCO: determination of transition state structures, barrier heights, and vibrational frequencies

1993 ◽  
Vol 71 (1) ◽  
pp. 135-140 ◽  
Author(s):  
J. S. Francisco ◽  
N. Mina-Camilde
Keyword(s):  
Transition State ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Chlorine Atom ◽  
Fluorine Atom ◽  
Hydrogen Abstraction ◽  
Barrier Heights ◽  
Optimized Geometries ◽  
Good Agreement

Theoretical barriers and reaction energetics were determined using ab initio calculations at the PMP4/6-311 + +G** level with UMP2/6-311G** optimized geometries for hydrogen abstraction reactions of HFCO and HClCO by fluorine and chlorine atoms. The largest barriers are predicted for fluorine and chlorine atom abstractions of hydrogen from HFCO. Fluorine and chlorine atom abstractions of hydrogen from HClCO are predicted to be barrierless. The predicted barrier for fluorine atom abstraction of hydrogen from HFCO is calculated to be 1.3 kcal mol−1 and is in good agreement with the experimental value of 1.8 ± 0.4 kcal mol−1.

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