Modulating the electronic properties of pendant groups through the redox switching reaction of a conjugated polymer

In this work we use the switching reaction of conductive polymers as a macr oscopic reversible command of the microscopic electronic properties of phen yl nuclei grafted on the polymer backbone. Two approaches, that potentially could enhance the modulation of these electronic properties, are investiga ted by means of IR spectroscopy: (i) the first consists in diluting the sub stituents along the polymer backbone by copolymerization of pyrrole and N-p henylpyrrole; (ii) in the second, 1,4-di(N-pyrrolyl)benzene (DPB) homopolym ers are used and make it possible to graft two conductive chains on the sub stituents. It is shown that the first strategy has little impact whereas th e second makes it possible to modulate the electronic properties of the ben zene nuclei in the opposite direction to that observed with poly(N-phenylpy rrole).