Substituent effect on NH bond dissociation enthalpies of amines and amides: A theoretical study

2008 ◽  
Vol 109 (3) ◽  
pp. 559-568 ◽  
Author(s):  
Damanjit Kaur ◽  
Rupinder Preet Kaur ◽  
Ruchi Kohli
Keyword(s):  
Substituent Effect ◽  
Theoretical Study ◽  
Bond Dissociation

Substituent effect on N–H bond dissociation enthalpies of carbamates: a theoretical study

2015 ◽  
Vol 93 (3) ◽  
pp. 279-288 ◽  
Author(s):  
Rupinder preet Kaur ◽  
Damanjit Kaur ◽  
Ritika Sharma
Keyword(s):  
Substituent Effect ◽  
Density Functional ◽  
Theoretical Study ◽  
Natural Bond Orbital ◽  
Stabilization Energy ◽  
Isodesmic Reactions ◽  
Bond Dissociation ◽  
Density Functional Methods ◽  
Functional Methods ◽  
Orbital Analysis

The present investigation deals with the study of the N–H bond dissociation enthalpies (BDEs) of the Y-substituted (NH2-C(=X)Y-R) and N-substituted ((R)(H)NC(=X)YH) carbamates (X, Y = O, S, Se; R = H, CH3, F, Cl, NH2), which have been evaluated using ab initio and density functional methods. The variations in N−H BDEs of these Y-substituted and N-substituted carbamates as the effect of substituent have been understood in terms of molecule stabilization energy (ME) and radical stabilization energy (RE), which have been calculated using the isodesmic reactions. The natural bond orbital analysis indicated that the electrodelocalization of the lone pairs of heteroatoms in the molecules and radicals affect the ME and RE values depending upon the type and site of substitution (whether N- or Y-). The variations in N−H BDEs depend upon the combined effect of molecule stabilization and radical stabilization by the various substituents.

THEORETICAL STUDY ON OXYGEN–OXYGEN HOMOLYTIC BOND DISSOCIATION ENTHALPIES OF PEROXIDES

2010 ◽  
Vol 09 (03) ◽  
pp. 625-635 ◽  
Author(s):  
CHUN-SEN ZOU ◽  
JING LIU
Keyword(s):  
Experimental Data ◽  
Substituent Effect ◽  
Theoretical Study ◽  
Theoretical Methods ◽  
Bond Dissociation ◽  
Oxygen Oxygen ◽  
Hammett Relationship

Seven theoretical methods (B3LYP, B3P86, X3LYP, BMK, MP2, CBS-QB3, G3B3) were employed to calculate oxygen–oxygen homolytic bond dissociation enthalpies of 13 peroxides. Comparison of the performances of these methods with the available experimental data showed that ROBMK method is suitable and economical for calculating O–O homolytic bond dissociation enthalpies of peroxides. Then ROBMK method was used to calculate O–O homolytic bond dissociation enthalpies of a series of peroxides. Meanwhile, the α-substituent effect and Hammett relationship were also discussed.

A Theoretical Study of the Effects of Protonation and Deprotonation on Bond Dissociation Energies

1995 ◽  
Vol 117 (34) ◽  
pp. 8816-8822 ◽  
Author(s):  
Susan L. Boyd ◽  
Russell J. Boyd ◽  
Paul W. Bessonette ◽  
Denise I. Kerdraon ◽  
Nicole T. Aucoin
Keyword(s):  
Theoretical Study ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies
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