The control of electron‐transfer processes is a major challenge in the design of molecular devices. Novel conjugared oligomers and polymers are presented in which photo‐ and redoxactive building blocks are linked by different spacers. It is also possible by chemical transformations to extend or interrupt &pgr;‐conjugation and to switch from localized to delocalized electronic states. By a proper choice of the spacer units the title systems are tailored for electron transfer.