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

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2016-07-18
JAYAMURUGAN, Govindasamy
GOWRI, Vijayendran
HERNANDEZ, David
MARTIN, Santiago
Gonzalez-Orive, Alejandro
Dengiz, Çağatay
DUMELE, Oliver
PEREZ-MURANO, Francesc
GISSELBRECHT, Jean-Paul
BOUDON, Corinne
SCHWEIZER, W. Bernd
BREITEN, Benjamin
FINKE, Aaron D.
JESCHKE, Gunnar
BERNET, Bruno
RUHLMANN, Laurent
CEA, Pilar
DIEDERICH, Francois
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.