Theoretical Calculations of Hydrogenation Enthalpies of Some Unsaturated Hydrocarbon Compounds

Authors

  • Mohammad Abd Al-Hakim Badawi
  • Ali Khairbek

Abstract

The standard enthalpies of hydrogenation of 29 unsaturated hydrocarbon compounds were calculated in the gaseous state by the CCSD(T) and M06-2X theories of levels with the complete basis 6-31g(d) and cc-pVXZ, where X =DZ, TZ, QZ, these enthalpies were calculated, as well as by complete basis set limit extrapolation using two different formulas.

Geometries of compounds were optimized at the M06-2X/6-31g(d) level. This M06-2X geometries were used in the M06-2X, CCSD(T) and extrapolation calculations with cc-pVXZ basis sets. Comparison of calculation and experimental results shows that the median absolute deviations (MAD) between the calculated and experimental enthalpies of hydrogenation range from 25.1 to 5.1 kJ mol-1 at M06-2X calculations and from 8.8 to 4.1 kJ mol-1 at CCSD(T) calculations. for both calculations, where using complete basis set limit extrapolation E(X) = E¥ + A/X3, the MAD have decreased to 2.7 and 1.5 kJ mol-1 respectively. The results of some calculations showed that the deviations from experimental values  are located inside the “chemical accuracy” (±1 kcal mol−1 ≈ ±4.2 kJ mol−1). Very good linear correlations between experimental and calculated enthalpies of hydrogenation have been obtained at M06-2X/TZ and CCSDT/TZ methods.

 

Downloads

Published

2019-11-07

How to Cite

1.
Badawi MAA-H, Khairbek A. Theoretical Calculations of Hydrogenation Enthalpies of Some Unsaturated Hydrocarbon Compounds. TUJ-BA [Internet]. 2019Nov.7 [cited 2024Nov.24];41(5). Available from: https://journal.tishreen.edu.sy/index.php/bassnc/article/view/9212

Issue

Vol. 41 No. 5 (2019): العلوم الأساسية

Section

Articles

License

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

The authors retain the copyright and grant the right to publish in the magazine for the first time with the transfer of the commercial right to the Tishreen University Journal -Basic Sciences Series  

 Under a CC BY- NC-SA 04 license that allows others to share the work with of the work's authorship and initial publication in this journal. Authors can use a copy of their articles in their scientific activity, and on their scientific websites, provided that the place of publication is indicted in Tishreen University Journal -Basic Sciences Series .  The Readers have the right to send, print and subscribe to the initial version of the article, and the title of Tishreen University Journal -Basic Sciences Series   Publisher

 

journal uses a CC BY-NC-SA license which mean

You are free to:

  • Adapt — remix, transform, and build upon the material
  •  
  • The licensor cannot revoke these freedoms as long as you follow the license terms.

 

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • NonCommercial — You may not use the material for commercial purposes.
  • ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
  • No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.