THE CHEMICAL BOND THEORY II

Chapter 10 has taught us that this theory is that of a simple formula for bond energies, namely, Eq. (10.37) 

A considerable simplification is achieved with a general formula [Eq. (10.50)], which incorporates these nonbonded contributions in an approximate manner. The unsigned average deviation with respect to the experimental results of seventyone saturated hydrocarbons, 0.19kcal/mol, certainly supports this simplified formula (see Part IH). 

Atomic Charges, Bond Properties, and Molecular Energies, by Sandor Fliszar Copyright 2009 John Wiley Sons, Inc. 

In order to extend the applicability of the same simple methods to olefinic, polyenic, and aromatic unsaturated hydrocarbons, additional parameters are required those for the bonds involving sp carbons. One must thus consider 

Accordingly, 10 new reference bond energies must be dehned. This is done with respect to the well-known bonds of ethane. In addition, seven additional parameters are to be evaluated by means of our standard formulas, Eqs. (10.41) and (11.16), with proper consideration of a- and rr-electron populations. All these transformations, including those dictated by changes of internuclear distances, are straightforward but require attention. 

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