Trends in Bond Dissociation Energies of Alcohols and Aldehydes Computed with Multireference Averaged Coupled-Pair Functional Theory

2014 ◽  
Vol 118 (17) ◽  
pp. 3039-3050 ◽  
Author(s):  
Victor B. Oyeyemi ◽  
John A. Keith ◽  
Emily A. Carter
Keyword(s):  
Bond Dissociation Energies ◽  
Functional Theory ◽  
Bond Dissociation ◽  
Dissociation Energies

THEORETICAL STUDIES ON BOND DISSOCIATION ENERGIES FOR SOME THIOL COMPOUNDS BY DENSITRY FUNCTIONAL THEORY AND CBS-Q METHOD

2008 ◽  
Vol 07 (05) ◽  
pp. 943-951 ◽  
Author(s):  
XIAO-HONG LI ◽  
ZHENG-XIN TANG ◽  
ABRAHAM F. JALBOUT ◽  
XIAN-ZHOU ZHANG ◽  
XIN-LU CHENG
Keyword(s):  
Density Functional ◽  
Computational Cost ◽  
Basis Set ◽  
Basis Sets ◽  
Q Method ◽  
Bond Dissociation Energies ◽  
Functional Theory ◽  
Thiol Compounds ◽  
Bond Dissociation ◽  
Dissociation Energies

Quantum chemical calculations are used to estimate the bond dissociation energies (BDEs) for 15 thiol compounds. These compounds are studied by employing the hybrid density functional theory (B3LYP, B3PW91, B3P86, PBE0) methods and the complete basis set (CBS-Q) method together with 6-311G** basis set. It is demonstrated that B3P86 and CBS-Q methods are accurate for computing the reliable BDEs for thiol compounds. In order to test whether the non-local BLYP method suggested by Fu et al.19 is general for our study and whether B3P86 method has a low basis set sensitivity, the BDEs for seven thiol compounds are also calculated using BLYP/6-31+G* and B3P86 method with 6-31+G*, 6-31+G**, and 6-311+G** basis sets for comparison. The obtained results are compared with the available experimental results. It is noted that B3P86 method is not sensitive to the basis set. Considering the inevitable computational cost of CBS-Q method and the reliability of the B3P86 calculations, B3P86 method with a moderate or a larger basis set may be more suitable to calculate the BDEs of the C–SH bond for thiol compounds.

HOMOLYTIC C–H BOND DISSOCIATION ENERGIES OF HTPB BINDER NETWORK

2009 ◽  
Vol 08 (03) ◽  
pp. 519-528 ◽  
Author(s):  
SONGNIAN LI ◽  
LUOXIN WANG ◽  
YONG LIU ◽  
XINLIN TUO ◽  
XIAOGONG WANG
Keyword(s):  
Density Functional Theory ◽  
Structural Analysis ◽  
Density Functional ◽  
Bond Dissociation Energies ◽  
Functional Theory ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Tertiary Carbon ◽  
Carbon Radicals ◽  
Secondary Carbon

The C – H bond dissociation energies (BDEs) of hydroxyl-terminated polybutadiene (HTPB) binder have been computed using ab initio and density functional theory methods. Five different HTPB carbon radicals were produced by the ruptures of different C – H bonds. The structural analysis of radicals and the calculated BDEs showed that the studied C – H bonds could be divided into three groups. It was found that the weakest C – H bonds were those on the tertiary carbon atom linked to a vinyl function. The next were those on the secondary carbon attached to a vinyl function. The dissociation of these two kinds of C – H bonds determines the structure of the ultimate products during the aging of HTPB binder. The most stable C – H bonds were those in the methylene that were attached to the saturated carbon atoms.

O - H Bond Dissociation Energies

2011 ◽  
Vol 64 (4) ◽  
pp. 394 ◽  
Author(s):  
Bun Chan ◽  
Michael Morris ◽  
Leo Radom
Keyword(s):  
Density Functional ◽  
Cost Effective ◽  
Closed Shell ◽  
Bond Dissociation Energies ◽  
Functional Theory ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Stabilization Energies ◽  
High Level ◽  
Precursor Molecules

High-level composite, ab initio and density functional theory (DFT) procedures have been employed to study O–H bond dissociation energies (BDEs), as well as radical stabilization energies (RSEs) in the oxygen-centred radicals that are formed in the dissociation of the O–H bonds. Benchmark values are provided by Wn results up to W3.2 and W4.x. We are able to recommend revised BDE values for FO–H (415.6 ± 3 kJ mol–1), MeC(O)O–H (459.8 ± 6 kJ mol–1) and CF3CH2O–H (461.9 ± 6 kJ mol–1) on the basis of high-level calculations. We find that Gn-type procedures are generally reliable and cost-effective, and that some contemporary functionals and double-hybrid DFT procedures also provide adequate O–H BDEs/RSEs. We note that the variations in the O–H BDEs are associated with variations in the stabilities of not only the radicals but also the closed-shell precursor molecules. Most substituents destabilize both species, with σ-electron-withdrawing groups having larger destabilizing effects, while π-electron acceptors are stabilizing. Although there is little correlation between the stabilizing/destabilizing effects of the substituents and the RSEs, we present some general patterns in the RSEs that emerge from the present study.

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