0000000000222244
AUTHOR
Jürgen Gerold
Oligo(phenylenevinylene)s with Terminal Donor–Acceptor Substitution This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.
Extension of Conjugation Leading to Bathochromic or Hypsochromic Effects in OPV Series
Four OPV series 1-4 (a-d) with a terminal dialkylamino group as electron donor were prepared by Wittig-Horner reactions. To study the influence of the push-pull effect on the long-wavelength absorption, three of the four series contained terminal acceptor groups (CN, CHO, NO(2)). The length of the chromophores strongly affects the intramolecular charge transfer (ICT)-an effect which superimposes upon the extension of the conjugation. Increasing numbers n of repeat units cause an overall bathochromic shift for the purely donor-substituted series 1 a-4 a and the series 1 b-4 b with CN as weak acceptor. The two effects annihilate each other in the series 1 c-4 c with terminal CHO groups, so th…
Push-Pull Oligomers with 2,2-Dicyanovinyl Groups as Electron Acceptors
Three conjugated oligomer series with terminal donor–acceptor substitution were studied: oligo(1,4-phenylenevinylene)s DAOPVs 4a–d (n = 1–4), oligo(1,4-phenyleneethynylene)s DAOPEs 6a–d (n = 1–4) and oligo(2,5-thienyleneethynylene)s DAOTEs 8a–e (n = 1–5). Dialkylamino or methoxy groups served as electron donors and 2,2-dicyanovinyl groups as strong electron acceptors. The push-pull effect polarizes the molecular chains – an effect which is documented by the splitting of the 13C chemical shifts of two carbon atoms of the double or triple bonds in the chain. For higher oligomers (n ≥ 3), the effect is mainly localized at the chain ends. The long-wavelength absorption results in a charge-trans…
The effect of 2,2-dicyanovinyl groups as electron acceptors in push–pull substituted oligo(1,4-phenylenevinylene)s
Abstract The newly synthesized oligo(1,4-phenylenevinylene) series 2a–d with bis(2-hexyloctyl)amino groups as electron donors and 2,2-dicyanovinyl groups as electron acceptors represents conjugated oligomers with strong push–pull effects. Due to the decrease of the intramolecular charge transfer with increasing numbers of repeat units (n=1–4), the long-wavelength transition shows a particularly great hypsochromic shift for the extension of the chromophore.