Additive bond energy scheme for the calculation of enthalpies of formation and bond dissociation energies for alkyl radicals

1996 ◽  
Vol 92 (22) ◽  
pp. 4415 ◽  
Author(s):  
Derek W. Smith
Keyword(s):  
Bond Energy ◽  
Enthalpies Of Formation ◽  
Bond Dissociation Energies ◽  
Alkyl Radicals ◽  
Bond Dissociation ◽  
Dissociation Energies

Theoretical Calculation of Bond Dissociation Energies and Enthalpies of Formation for Halogenated Molecules

2001 ◽  
Vol 105 (27) ◽  
pp. 6729-6742 ◽  
Author(s):  
Yannis G. Lazarou ◽  
Alexandros V. Prosmitis ◽  
Vassileios C. Papadimitriou ◽  
Panos Papagiannakopoulos
Keyword(s):  
Theoretical Calculation ◽  
Enthalpies Of Formation ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies

The C—Br bond dissociation energy in substituted benzyl bromides

1951 ◽  
Vol 209 (1096) ◽  
pp. 97-110 ◽  
Keyword(s):  
Bond Energy ◽  
Benzyl Bromide ◽  
Frequency Factor ◽  
Unimolecular Dissociation ◽  
Bond Dissociation Energies ◽  
Kcal Mole ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Rate Determining Step

The ‘toluene-carrier’ technique has been used for the determination of the C—Br bond dissociation energies in the substituted benzyl bromides: p -, m - and o -xylyl bromides; p -, m - and o -chlorobenzyl bromides; p - and m -bromobenzyl bromides; p - and m -nitrobenzyl bromides; and p - and m -nitrilebenzyl bromides. The rate-determining step of the decompositions of all these compounds is represented by the unimolecular dissociation processes ( s ) Ph s . CH 2 . Br → Ph s . CH 2 • + Br, ( s ) where Ph s . CH 2 . Br refers to the substituted benzyl bromide. Assuming that the frequency factor of the decomposition of each benzyl bromide is equal to the frequency factor of reaction ( u ) Ph . CH 2 . Br → Ph . CH 2 • + Br, ( u ) the differences in activation energies between E u and E s were calculated using the relation E u ─ E s = RT In ( k s / k u ); (I) k s and k u denote the unimolecular rate constants of reactions ( s ) and ( u ) respectively. Since E s and E u are equal to the C—Br bond dissociation energies in the substituted benzyl bromides and benzyl bromide itself, equation (I) yields the differences, ∆ D’ s, between D ( Ph . CH 2 —Br) and the values for D ( Ph s . CH 2 —Br). The calculated differences in the C—Br bond dissociation energies are listed below: substituted ∆ D substituted ∆ D benzyl bromides (kcal. /mole) benzyl bromides (kcal. /mole) o -chloro 0·9 m -methyl 0-0 m -chloro 0·1 p -methyl 1·4 p -chloro 0·4 m -nitro 2·1 m -bromo 0·3 p -nitro 1·1 p -bromo 0·3 m -nitrile 1·4 o -methyl 2·0 p -nitrile 0·7 The significance of these findings is discussed, and the effect of substitution on a bond energy is contrasted with the effect of ionic reactions.

Enthalpies of Formation, Bond Dissociation Energies and Reaction Paths for the Decomposition of Model Biofuels:  Ethyl Propanoate and Methyl Butanoate†

2007 ◽  
Vol 111 (19) ◽  
pp. 3727-3739 ◽  
Author(s):  
Ahmed M. El-Nahas ◽  
Maria V. Navarro ◽  
John M. Simmie ◽  
Joseph W. Bozzelli ◽  
Henry J. Curran ◽  
...  
Keyword(s):  
Enthalpies Of Formation ◽  
Bond Dissociation Energies ◽  
Reaction Paths ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Methyl Butanoate
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