Hypohomodesmotic reactions

Hypohomodesmotic reactions describe chemical reactions of hydrocarbon compounds for which the following applies:

the number of carbon-hydrogen bonds remains constant
in each hybridization stage the number of carbon atoms remains constant.

In the theoretical prediction of reaction energies, errors in the calculation methods are more significant, since reaction energies are small quantities in terms of magnitude compared to the energies, the difference between which they result. Systematic errors generally cancel each other out in the formation of differences. Thus, in theoretical chemistry it makes sense to characterize reactions according to the type of systematic error, the influence of which can be neglected when calculating the reaction energy.

definition

A hypohomodesmotic reaction is a reaction of hydrocarbons for which the following applies:

the number of carbon-hydrogen bonds remains constant and
in each hybridization stage the number of carbon atoms remains constant.

Hypohomodesmotic reactions are always isogyric reactions and isodesmic reactions .

example

${\ displaystyle \ mathrm {1-witches + ethane \ \ longrightarrow \ 1-butene + butane}}$

Educts

1-Hexene has 12 carbon-hydrogen bonds, 2 sp ² and 4 sp ³ hybridized carbon atoms.
Ethane has 6 carbon-hydrogen bonds and 2 sp ³ -hybridized carbon atoms.
The educts have a total of 18 carbon-hydrogen bonds, 2 sp ² and 6 sp ³ hybridized carbon atoms.

Products

1-butene has 8 carbon-hydrogen bonds, 2 sp ² and 2 sp ³ hybridized carbon atoms.
Butane has 10 carbon-hydrogen bonds and 4 sp ³ -hybridized carbon atoms.
The products have a total of 18 carbon-hydrogen bonds, 2 sp ² and 6 sp ³ hybridized carbon atoms.

Web links

Isodesmic Reactions. Ludwig Maximilians University of Munich , April 24, 2009.; accessed on August 10, 2020
Homodesmotic Reactions. Retrieved August 10, 2020(English).

Individual evidence

↑ Steven E. Wheeler, Kendall N. Houk, Paul v. R. Schleyer, Wesley D. Allen: A Hierarchy of Homodesmotic Reactions for Thermochemistry . In: Journal of the American Chemical Society . tape 131 , no. 7 , February 25, 2009, p. 2547-2560 , doi : 10.1021 / ja805843n .
↑ http://ursula.chem.yale.edu/~chem220/chem220js/STUDYAIDS/thermo/homodesmotic/homodesmotic.html

[1] Steven E. Wheeler, Kendall N. Houk, Paul v. R. Schleyer, Wesley D. Allen: A Hierarchy of Homodesmotic Reactions for Thermochemistry . In: Journal of the American Chemical Society . tape 131 , no. 7 , February 25, 2009, p. 2547-2560 , doi : 10.1021 / ja805843n .

[2] ttp://ursula.chem.yale.edu/~chem220/chem220js/STUDYAIDS/thermo/homodesmotic/homodesmotic.html