The Crystal Structure of (NH4)2Cr2O7. With a Discussion of the Relation between Bond Number and Interatomic Distances.

Abstract

It is shown that in hydrocarbons the bond energy is inversely proportional to the cube of the bond length; the following equations summarize the observed data: ECH = 128.21Lo~-~; Ecc = 312.33Lcc-a. The increase in energy associated with the shortening of a CIX bond adjacent t? an unsaturated CC bond is of the same magnitude aa that associated with the shortening of a CC bond due to hyperconjugation.