Oligo(phenylenevinylene)s with Terminal Donor–Acceptor Substitution This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.

Hypsochromic or bathochromic? Depending upon the acceptor group (A=H, CN, CHO, NO2) the position and intensity of the absorption maxima of a series of substituted oligo(phenylenevinylene)s change (see picture). Supported by semi-empirical calculations, the extent and direction of the shift (hypsochromic or bathochromic) is attributable to the opposing effects of length of conjugation and charge transfer.