Novel electron-deficient oligo(phenyleneethynylene) derivatives for molecular electronics

ABSTRACT

This work reports synthesis and characterizations of two new electron-poor “oligo(phenyleneethynylene) (OPE) type” molecular wires for fundamental studies of electron transport in molecular junctions. These OPE derivatives display three aromatic rings functionalized (i) with NO₂ (OPN) or fluorine (OPF) groups on the central aryl core and (ii) with the requisite protected thiolate anchoring groups on the lateral rings at both ends. We show that the moderately effective Sonogashira couplings can give access to such rare electrodeficient molecules but are unfortunately associated with significant side reactions. We detail the choice of adequate reaction conditions to allow the recovery of suitable amounts of compounds bearing several strongly electron-withdrawing substituents on their central ring for further study of the physical properties.

GRAPHICAL ABSTRACT

KEYWORDS:

• Dinitrobenzene
• molecular electronics
• oligo(phenylethylene)
• Sonogashira coupling tetrafluorobenzene

Additional information

Funding

This work was supported by the Université de Rennes 1, the CNRS, and the Agence Nationale de la Recherche (RuOxLux—ANR-12-BS07-0010-01). RK thanks the Algerian Ministry of High Education and Scientific Research for his Grant (Profas). We also thank Gilles Alcaraz for discussions.