Most polymers adopt helical conformation in solution and/or in the solid state. An interesting class of optically active polymers is based on the enantioselective induction of main-chain chirality by the presence of enantiomerically pure side chain and belonging to them are chiral p-conjugated polymers. In this proposal we intend to deepen in the study of the inversion of chirality in optically active p-conjugated polymers, extending this study from the polythiophenes to other different p-conjugated polymers and to polymers with other functional groups which could regulate the stereomutation. In addition we pretend to study the chain-length dependence of the main-chain chirality using a series of regularly substituted oligothiophenes. Furthermore we want to study the stereomutation by external stimuli, using chiral oligoethylenes as substituents to polythiophenes, allowing the complexation of cations. We also propose to use Circular Dichroism of optically active polymers to elucidate the process of association prior to crystallization. The possible application of the inversion of main-chain chirality of p-conjugated polymers could lead to a polymer alternative for a reversible MO-recording based on chirality.