Conducting-polymer electrochemical switching as an easy means for control of the molecular properties of grafted transition metal complexes.
Copper(II) 3',4'-bis(N,N'-oxamato)terthiophene has been synthesized and electropolymerized. The copper(II)-complex centers are not affected by the polymerization process, which involves coupling between Calpha carbon atoms of the terthiophene units and leads to a new conjugated polymer consisting of polythiophene chains bearing bis(oxamato)-Cu(II) groups regioregularly grafted onto the polymer backbone. The polymer is stable with respect to polythiophene electroactivity, and no demetallation or modification of the Cu oxidation state occurs over a large potential range. In this material, the two moieties exhibit direct electronic interaction, which makes it possible to use the conductive polymer backbone as a molecular wire or a nanocontact capable of inputting to the bis(oxamato)-Cu(II) groups through the polythiophene-switching reaction. FTIR, XPS, and XAS spectroscopies have been used to study the effect of the state of the conducting polymer upon the properties of the copper(II) center (electron density, ligand field strength, size of cavity, force constants of some bonds). These properties can be controlled to some extent by the potential applied to this device. From the point of view of the copper(II) center, this effect is similar to the grafting of substituents with various electronic properties.
Mangeney
C
C
Institut de Topologie et de Dynamique des Systèmes, Université Paris 7-Denis Diderot, France.
Lacroix
J C
JC
Chane-Ching
K I
KI
Jouini
M
M
Villain
F
F
Ammar
S
S
Jouini
N
N
Lacaze
P C
PC