Photoluminescent Amphiphilic 1,4-diketo-3,6-diphenylpyrrolo-[3,4-c]-pyrrole derivative and its complexes with polyelectrolytes

The new amphiphile 1,4-diketo-5-methyl-2-(11-undecyl sulfate sodium salt)-3-(4-chlor)phenyl-6-phenylpyrrolo-[3,4-c]-pyrrole (Na-1) is described, carrying the diketopyrrolopyrrole chromophore in the hydrophobic part. An aqueous solution of Na-1 exhibits an orange color with an absorption maximum at 475 nm and a red-orange fluorescence with a maximum at 529 nm. The critical micelle concentration in water is 4.1 x 10(-5) mol/L. Highly concentrated aqueous solutions exhibit lyotropic phase behavior. Na-1 crystallizes into a lamellar structure. After heating to the melting point, the compound does not recrystallize upon cooling but forms a supercooled melt with a glass transition temperature. The combination of aqueous solutions of Na-1 and cationic polyelectrolytes in a stoichiometric ratio leads to the formation of polyelectrolyte-surfactant complexes with mesomorphous structure and a glass transition temperature depending on the structure of the polyelectrolyte. Complexes of Na-1 with poly(allylamine hydrochloride) and poly [(methylbutylimino)hexy-lene bromide] are characterized. The optical properties of the complexes are comparable with those of Na-1, while the solubility is clearly lower. Because of their convenient optical properties and their plasticity and resistance to solvents, the complexes represent interesting new materials with potential applications as coloring agents.