Increase in Strain Energy on Going from [4.4.4.5]Fenestrane to [4.4.4.4]Fenestrane A Method for Estimating the Heats of Formation of Hydrocarbons and their Derivatives from ab Initio Energies

The Journal of Organic Chemistry
Kenneth B Wiberg, Paul R Rablen

Abstract

Our interest in the fenestranes led us to wonder how large the change in strain energy with changes in ring size might be. This led us to consider if satisfactory estimates of heat of formation could be readily derived from ab initio calculated energies. We started by examining 21 hydrocarbons having well determined heats of formation via calculations of their enthalpies using W1BD, G4, CBS-APNO, CBS-QB3 and M062X. Making use of the molecular formula and an initial estimate of the energy of a hydrogen atom and of a carbon atom, along with the ab initio enthalpy, we calculated their heats of formation. The carbon energy parameter was adjusted slightly for each model to get the best fit between experiment and our estimate. This approach worked out very well giving an RMS error of about 0.4 kcal/mol for most methods. The method was also extended to a larger group of hydrocarbons, and the results were found to be generally useful. The extension to O and N compounds also was examined giving equally good results for the O-containing compound, but somewhat less satisfactory with N containing compounds. In use, the procedure requires only the molecular formula, the calculated energy, and C, H, O and N atomic constants given in the Tables.

References

Oct 18, 1996·The Journal of Organic Chemistry·Lisa E. BoyerBrian Zanoni
Oct 18, 2006·The Journal of Chemical Physics·Amir KartonBranko Ruscic
Mar 9, 2007·The Journal of Chemical Physics·Larry A CurtissKrishnan Raghavachari
Oct 2, 2007·The Journal of Chemical Physics·Larry A CurtissKrishnan Raghavachari
Mar 26, 2008·The Journal of Chemical Physics·Michael E HardingJohn F Stanton
Feb 19, 2009·The Journal of Physical Chemistry. a·W S OhlingerW J Hehre
Jan 21, 2014·The Journal of Organic Chemistry·Paul R RablenJean E Schneider
Jun 23, 2015·Journal of Computational Chemistry·Amir KartonJan M L Martin
Jun 30, 2015·Angewandte Chemie·Li-Ming YangPaul von Ragué Schleyer

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Citations

Aug 19, 2020·The Journal of Organic Chemistry·Kenneth B Wiberg, Paul R Rablen

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