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.
