Bond energy M–C/H–C correlations: dual theoretical and experimental approach to the sensitivity of M–C bond strength to substituentsElectronic supplementary information (ESI) available: methods of calculation; Fig. S1: Comparison of calculated and experimental C–H bond dissociation energies for organic molecules; Table S1, comparison of calculated and experimental CO-stretching frequencies; Table S2, total energies, BDE for Re–C and H–C; Table S3, NPA charges q(C) and q(aryl) for the organic fragments C6H6–nFn and the rhenium complexes; preparation and spectroscopic data for Re(η5-C5Me5)(CO)2(2,6-C6H3F2)H. See http://www.rsc.org/suppdata/cc/b2/b210036n/

2003 ◽  
pp. 490-491 ◽  
Author(s):  
Eric Clot ◽  
Maria Besora ◽  
Feliu Maseras ◽  
Claire Mégret ◽  
Odile Eisenstein ◽  
...  
Keyword(s):  
Bond Strength ◽  
Bond Energy ◽  
Spectroscopic Data ◽  
Organic Molecules ◽  
Experimental Approach ◽  
Supplementary Information ◽  
Bond Dissociation Energies ◽  
Dissociation Energies ◽  
Methods Of Calculation ◽  
Total Energies

Bond Dissociation Energies of Organic Molecules

2003 ◽  
Vol 36 (4) ◽  
pp. 255-263 ◽  
Author(s):  
Stephen J. Blanksby ◽  
G. Barney Ellison
Keyword(s):  
Organic Molecules ◽  
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.

Bond Dissociation Energies of Organic Molecules

ChemInform ◽  
2003 ◽  
Vol 34 (24) ◽  
Author(s):  
Stephen J. Blanksby ◽  
G. Barney Ellison
Keyword(s):  
Organic Molecules ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies
Sign in / Sign up

Export Citation Format

Share Document