Formation of electrochromic systems based on noncovalently associated polymer-viologen complexes

New composite electrochromic systems combining the advantages of low-molecular-mass organic electrochroms??high molar-absorption coefficients in the colored state and high switching rates??with good properties of polymers??such as mechanical strength and film-formation ability??are prepared through the incorporation of low-molecular-mass viologens into a carboxyl-containing polymer matrix via noncovalent binding. The formation of noncovalently bound polymer-viologen complexes is confirmed by IR and UV spectroscopy. It is found that the degree of substitution in a viologen molecule strongly affects the character of interaction with the polymer matrix and the electrochromic properties of the composite.