A Semi-empirical Theory of the Conjugated Systems, III. Bond Alternation and Electron Fixation

Extending the previous treatment of the author on the bond alternation in infinite conjugated systems to finite systems, it is investigated why the wave-lengths of some homologous series appear to tend to infinity while those of others to finite limits when the number of carbon atoms increases. It is concluded that the bond alternation does not occur in shorter symmetrical or slightly unsymmetrical chains, while, in strongly unsymmetrical chains, the bond alternation always occurs and that it always occurs in longer chains according to the result in the previous paper.