Interchain interactions in pi-conjugated oligomers and polymers: a primer

In this contribution, we review our recent quantum-chemical studies on inte rmolecular interactions and the way they impact the transport and optical p roperties of organic conjugated materials. When applied to the crystalline structures of two prototypical oligomeric materials, alpha -sexithienyl and alpha-alpha ' -bisdithieno[3,2-b:2 ' ,3 ' -d]thiophen our approach illustr ates how the variations in chain packing lead to dramatically different opt ical splittings and carrier mobilities. Various strategies to prevent solid -state luminescence quenching in light-emitting devices are proposed.