Density functional theory for N–NO2 bond dissociation energies of N-nitroacylamide compounds in acetonitrile — Theoretical method assessment and prediction

2012 ◽  
Vol 90 (6) ◽  
pp. 526-533
Author(s):  
Xiaohong Li ◽  
Huixian Wang ◽  
Zhumu Fu ◽  
Xianzhou Zhang
Keyword(s):  
Density Functional ◽  
Substituent Effects ◽  
Theoretical Method ◽  
Bond Dissociation Energies ◽  
Absolute Deviation ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Maximum Absolute Deviation ◽  
Electron Withdrawing Group ◽  
Experimental Values

The performance of various density functional theories (B3LYP, B3PW91, B3P86, B1LYP, BMK, MPWB1K, PBE0, and MPWB95) was examined for calculating N–NO2 bond dissociation energies (BDEs) of 10 N-nitroacylamide compounds. The CBS-4M method was also used. By comparing the calculated results with the experimental values, it was observed that B1LYP/6–31G** and B3LYP/6–31+G** provided accurate BDEs. Especially, B3LYP/6–31+G** was recommended because of its smaller maximum absolute deviation. Further, substituent effects based on the B3LYP/6–31+G** method were analyzed. The result shows that an electron-donating group increases the BDE of the parent C6H5–CON(CH3)NO2, while an electron-withdrawing group decreases the BDE of the parent C6H5–CON(CH3)NO2. Subsequently, the BDEs of the other N-nitroacylamindes were estimated.

Assessment of PBE0 Calculation of C-NO2 Bond Dissociation Energies for Nitroaromatic System

2014 ◽  
Vol 915-916 ◽  
pp. 675-678
Author(s):  
Xin Fang Su ◽  
Wei Huang ◽  
Hai Ying Wu
Keyword(s):  
Density Functional ◽  
Molecular System ◽  
Absolute Error ◽  
Basis Sets ◽  
Bond Dissociation Energies ◽  
Average Absolute Error ◽  
Functional Theory ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Experimental Values

Density functional theory (DFT) is used to calculate the C-NO2bond dissociation energies (BDEs) in nitrobenzene; 3-amino-nitrobenze; 4-amino-nitrobenze; 1,3-dinitrobenzene; 1,4-dinitrobenzene; 2-methyl-nitrobenzene; 4-methyl-nitrobenzene and 1,3,5-trinitrobenzene nitroaromatic molecular system. B3P86 and PBE0 methods in combination with 6-31G** and 6-311G** basis sets are employed. Comparison between the computational results and the experimental values reveals that the calculated C-NO2bond BDEs can be improved from B3P86 to PBE0 functional. Level of theory employing PBE0/6-311G** is found to be sufficiently reliable to compute BDEs of C-NO2bond for nitroaromatic molecules with an average absolute error of 0.98 kcal mol-1.

Polarized continuum model study of bond dissociation energies of the O–NO2 bond — A density functional theory study and natural bond order analysis

2012 ◽  
Vol 90 (5) ◽  
pp. 433-440
Author(s):  
Zhang Ruizhou ◽  
Fu Zhumu ◽  
Li Xiaohong ◽  
Zhang Xianzhou
Keyword(s):  
Density Functional ◽  
Parent Compound ◽  
Substituent Effects ◽  
Accurate Method ◽  
Basis Sets ◽  
Acetonitrile Solution ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Polarized Continuum Model

Density functional methods (B3LYP, B3PW91, B3P86, and MPWB95) with 6–31G** basis sets and complete basis methods are employed to investigate the bond dissociation energies (BDEs) of the O–NO2 bond for seven O-nitroalcohol compounds in acetonitrile solution. B3LYP/6–31+G**, (RO)B3LYP/6–311++G(2df,2p), and B3LYP/6–311G(d,p) methods are also used. By comparing the calculated results with the experimental values, B3LYP/6–31+G** is the most accurate method to compute the reliable BDEs for the studied compounds. The substituent effects on the O–NO2 BDEs are analyzed. It is found that electron-withdrawing groups increase the BDE of the parent compound, whereas electron-donating groups decrease the BDE of the parent compound. Further, the natural bond orbital analysis shows that there exist good linear correlations between E(2) and Hammett constants, the BDE, and the difference of the second-order stabilization energies E(2) of lpO3 → BD*(O1–N1) and lpO3 → BD*(O2–N1).

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.

Bond dissociation energies in organometallic systems: substituent effects

2014 ◽  
Vol 27 (11) ◽  
pp. 850-859 ◽  
Author(s):  
Olga V. Kuznetsova ◽  
Alexey N. Egorochkin ◽  
Nadiya M. Khamaletdinova ◽  
Lada G. Domratcheva-Lvova
Keyword(s):  
Substituent Effects ◽  
Bond Dissociation Energies ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Organometallic Systems

scholarly journals An Accurate and Efficient Method to Predict Y-NO Bond Homolysis Bond Dissociation Energies

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Hong Zhi Li ◽  
Lin Li ◽  
Zi Yan Zhong ◽  
Yi Han ◽  
LiHong Hu ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Molecular Descriptors ◽  
Basis Set ◽  
Bond Dissociation Energies ◽  
Data Set ◽  
Test Set ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Bond Homolysis

The paper suggests a new method that combines the Kennard and Stone algorithm (Kenstone, KS), hierarchical clustering (HC), and ant colony optimization (ACO)-based extreme learning machine (ELM) (KS-HC/ACO-ELM) with the density functional theory (DFT) B3LYP/6-31G(d) method to improve the accuracy of DFT calculations for the Y-NO homolysis bond dissociation energies (BDE). In this method, Kenstone divides the whole data set into two parts, the training set and the test set; HC and ACO are used to perform the cluster analysis on molecular descriptors; correlation analysis is applied for selecting the most correlated molecular descriptors in the classes, and ELM is the nonlinear model for establishing the relationship between DFT calculations and homolysis BDE experimental values. The results show that the standard deviation of homolysis BDE in the molecular test set is reduced from 4.03 kcal mol−1calculated by the DFT B3LYP/6-31G(d) method to 0.30, 0.28, 0.29, and 0.32 kcal mol−1by the KS-ELM, KS-HC-ELM, and KS-ACO-ELM methods and the artificial neural network (ANN) combined with KS-HC, respectively. This method predicts accurate values with much higher efficiency when compared to the larger basis set DFT calculation and may also achieve similarly accurate calculation results for larger molecules.

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