Design and Synthesis of Aviram-Ratner-Type Dyads and Rectification Studies in Langmuir-Blodgett (LB) Films


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JAYAMURUGAN G., GOWRI V., HERNANDEZ D., MARTIN S., Gonzalez-Orive A., Dengiz C. , ...More

CHEMISTRY-A EUROPEAN JOURNAL, vol.22, no.30, pp.10539-10547, 2016 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 30
  • Publication Date: 2016
  • Doi Number: 10.1002/chem.201505216
  • Title of Journal : CHEMISTRY-A EUROPEAN JOURNAL
  • Page Numbers: pp.10539-10547
  • Keywords: [2+2] cycloaddition-retroelectrocyclization, Aviram-Ratner dyad, charge transfer, Langmuir-Blodgett films, molecular electronics materials, INTRAMOLECULAR CHARGE-TRANSFER, SELF-ASSEMBLED MONOLAYERS, SCANNING-TUNNELING-MICROSCOPY, HOMO-LUMO GAP, MOLECULAR RECTIFICATION, GOLD ELECTRODES, ELECTRICAL RECTIFICATION, HEXADECYLQUINOLINIUM TRICYANOQUINODIMETHANIDE, 7,7,8,8-TETRACYANOQUINODIMETHANE TCNQ, DONOR-(PI-BRIDGE)-ACCEPTOR DYE

Abstract

The design and synthesis of Aviram-Ratner-type molecular rectifiers, featuring an anilino-substituted extended tetracyanoquinodimethane (exTCNQ) acceptor, covalently linked by the sigma-spacer bicyclo[2.2.2]octane (BCO) to a tetrathiafulvalene (TTF) donor moiety, are described. The rigid BCO spacer keeps the TTF donor and exTCNQ acceptor moieties apart, as demonstrated by X-ray analysis. The photophysical properties of the TTF-BCO-exTCNQ dyads were investigated by UV/Vis and EPR spectroscopy, electrochemical studies, and theoretical calculations. Langmuir-Blodgett films were prepared and used in the fabrication and electrical studies of junction devices. One dyad showed the asymmetric current-voltage (I-V) curve characteristic for rectification, unlike control compounds containing the TTF unit but not the exTCNQ moiety or comprising the exTCNQ acceptor moiety but lacking the donor TTF part, which both gave symmetric I-V curves. The direction of the observed rectification indicated that the preferred electron current flows from the exTCNQ acceptor to the TTF donor.