Formation of Specific Charge-transfer Complexes between Hyperbranched Polymer Viologen and Neutral Donors in Solid Films Depending on Donor Fraction

Neutral donors and hyperbranched polymer with many viologen groups formed charge-transfer complexes in solutions and solid films. The charge-transfer absorption and fluorescence spectra showed red shifts with increasing donor fractions only in the case of polymer solid films, strongly suggesting solvatochromism in solid films and formation of multichromophore CT complex. These are unique microenvironmental effects of the present cationic polymer.