COMPARTMENTALIZATION OF CHROMOPHORES IN A MOLECULAR COMPOSITE CONSISTING OF AMPHIPHILIC POLYELECTROLYTE SURFACTANT ION COMPLEXES

A molecular composite of an amphiphilic polyanion and cationic surfactants was prepared by treating a terpolymer [consisting of sodium 2-acrylamido-2-methylpropanesulfonate, N-(1-adamantyl) methacrylamide, and a small mole fraction of N-(1-pyrenylmethyl) methacrylamide] with didodecyldimethylammonium bromide in aqueous solution. The molecular composite was soluble in organic solvents with a wide range of polarities. Fluorescence spectra indicated that the pyrenyl (Py) residues in the molecular composite experienced polar microenvironments even though the composite was dissolved in nonpolar solvents. Exciplex formation of the Py residue with 4,4'-dicyanobenzene was strongly suppressed due to the polar microenvironments and steric "protection" of the chromophore. Photoinduced electron transfer (ET) from the Py residue to pyromellitic dianhydride (PMDA) in acetonitrile showed characteristics of long-range ET between fixed donor and acceptor sites and yielded long-lived transient Py cation radicals and PMDA anion radicals which persisted for tens of milliseconds. These findings imply that the micellelike structure of the parent amphiphilic polyelectrolyte formed in aqueous solution is retained, to some degree, in the molecular composite dissolved in organic solvents.