The title compounds are prepared by slow evaporation of dilute solutions of the components. 2,3,7,8-Tetrakis(methylthio)thianthrene and -selenanthrene give isostructural 2:1 complexes with 7,7,8,8-tetracyanoquinodimethane (TCNQ) built up by donor/acceptor/donor units in which the TCNQ molecule is inserted into the cavity formed by two of the folded, oppositely arranged chalcogenanthrene molecules. These units are connected to chains by S -S contacts via the methylthio groups. From 2,3,7,8-tetrakis(methylthio)thianthrene and tetracyanoethene again a 2:1 complex is obtained, however, with a columnar structure in which two donor stacks are slightly interlinked by an acceptor stack thus forming a structure with alternating donor and acceptor molecules. The molecules are arranged in such a way that an optimum overlap of the HOMOs of the donors and the LUMOs of the acceptors, all of which are of π-type character according to MNDO calculations, is secured.