Estimation of Heats of Formation of Organic Compounds

1965 ◽  
Vol 4 (4) ◽  
pp. 389-396 ◽  
Author(s):  
K. K. Verma ◽  
L. K. Doraiswamy
Keyword(s):  
Organic Compounds ◽  
Heats Of Formation

Heats of Formation of Organic Compounds by a Simple Calculation

2010 ◽  
Vol 75 (19) ◽  
pp. 6502-6515 ◽  
Author(s):  
Andreas A. Zavitsas ◽  
Donald W. Rogers ◽  
Nikita Matsunaga
Keyword(s):  
Organic Compounds ◽  
Simple Calculation ◽  
Heats Of Formation

scholarly journals A Comparison of the Accuracy of Semi-empirical PM3, PDDG and PM6 methods in Predicting Heats of Formation for Organic Compounds

2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Yang-Yang Wu ◽  
Feng-Qi Zhao ◽  
Xue-Hai Ju
Keyword(s):  
Organic Compounds ◽  
Least Square Method ◽  
Least Square ◽  
Heats Of Formation ◽  
Regression Equations ◽  
Chemical Calculation ◽  
Average Deviation ◽  
Experimental Values ◽  
Isomerization Energy ◽  
Semi Empirical

<p>Gas phase heats of formation (HOF) of 18 kinds of 390 organic compounds were calculated by quantum chemical calculation using semi-empirical PM3, PDDG and PM6 methods. The calculated HOFs were compared with the experimental data to illustrate the accuracy for different kinds of organics. Furthermore, the calculated values were linearly fitted with experimental values using the least square method, and were afterward substituted into the fitted regression equations to obtain the calibrated ones. The results show that, for 10 kinds of the selected organics, PM6 is more accurate, and PDDG is more accurate for 7 kinds of organics, while PM3 is only good for amino acid. As a whole, PM6 predicts the HOFs more accurately, with its weighted total mean average deviation (WTMAD) being 0.4 kJ/mol and 2.4 kJ/mol smaller than those of PM3 and PDDG, respectively. On the other hand, our results show that PDDG is the best to differentiate the isomers, with its mean average deviation (MAD) for isomerization energy being 7.8 kJ/mol and 11.0 kJ/mol smaller than PM6 and PM3, respectively. After the calibration, the values of MADs from the PM3, PDDG and PM6 results for most organics are reduced by 0.1 to 18.2 kJ/mol, with exceptions of the PM3 for amines, PDDG for carboxylic acids, and PM6 for ethers.</p>

Calculation of "Dewar" resonance energies in conjugated organic molecules

1969 ◽  
Vol 47 (19) ◽  
pp. 3535-3538 ◽  
Author(s):  
N. C. Baird
Keyword(s):  
Organic Compounds ◽  
Organic Molecules ◽  
Resonance Energy ◽  
Heats Of Formation ◽  
Conjugated Organic Molecules ◽  
Resonance Energies ◽  
Definition Of

Dewar's recent definition of resonance energy (1) for hydrocarbons is extended to molecules containing oxygen, and resonance energy values are calculated from experimental heats of formation for a variety of conjugated organic compounds. A simple additivity scheme is proposed whereby resonance energies and heats of formation can be accurately estimated for benzenoid systems.

scholarly journals Heats of Formation of Medium-Sized Organic Compounds from Contemporary Electronic Structure Methods

2017 ◽  
Vol 13 (8) ◽  
pp. 3537-3560 ◽  
Author(s):  
Yury Minenkov ◽  
Heng Wang ◽  
Zhandong Wang ◽  
S. Mani Sarathy ◽  
Luigi Cavallo
Keyword(s):  
Electronic Structure ◽  
Organic Compounds ◽  
Heats Of Formation ◽  
Electronic Structure Methods

Estimation of heats of formation of organic compounds by additivity methods

1993 ◽  
Vol 93 (7) ◽  
pp. 2419-2438 ◽  
Author(s):  
N. Cohen ◽  
S. W. Benson
Keyword(s):  
Organic Compounds ◽  
Heats Of Formation
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