Elaboration et Caractérisation de fils moléculaires Et applications .

Abstract

This work is devoted to the synthesis and characterization of OPE-type molecular threads as well as metal alkynyl with cyclam ligand complexes. In the first part of this manuscript, we presented the synthesis of OPE (Oligo(phenylene ethylene)) molecular wires with different central cores in order to obtain various wire with different HOMO-LUMO energy levels. Our (collaborative) goal is to check and rationalize the pinning effect factor occurring in molecular junctions with these molecular wires using CP-AFM and MCBJ conductivity techniques and theoretical calculations. This technique demonstrated the origin of the pinning effect as being a strong hybridization between the orbitals of the anchoring group and those of the metal atoms. The insertion of saturated spacers is a simple way of reducing the pinning effect, by reducing the strong coupling established between the molecular wires and the electrode. In the second part we present the synthesis of the three metal alkynyl with cyclam ligand complexes. This kind of complexes possessing conductive, voltammetric and magnetic properties, their electronic flexibility conferring on them specific molecular characteristics that we can use it for applications in electronics industries.