Cohesion and optical activity of organic chain compounds

Unusual cohesion (fractional charge transfer, charged sheets) and optical a ctivity (far infrared anomalies) of organic chain compounds are explained w ithin the theory which includes interband processes, i.e, dipole-dipole and monopole-dipole interactions, on both, donor and acceptor, chains. The ana lysis based on our recent tight-binding dielectric formalism, shows that th ese unusual properties are related to the softening of hybridized collectiv e modes.