Cross-conjugation
From Wikipedia, the free encyclopedia
Cross-conjugation is a special type of conjugation in a molecule, when in a set of three Pi bonds only two pi-bonds interact with each other by conjugation, the third one is excluded from interaction.[1] In classical terms it means that the strict alternation of single and double bonds—CH=CH–CH=CH–CH-- (i.e., conjugated) is interrupted by two consecutive single bonds at each cross-conjugated point in the cross-conjugated pathway: --CH=CH–C(=CR2)–CH=CH--. Examples of cross-conjugation can be found in molecules such as benzophenone, divinylketones, p-quinones, dendralenes, radialenes, and fullerene. The type of conjugation has an impact on reactivity and molecular electronic transitions.
