AbstractWe investigated the association of linear cationic model polyelectrolytes with oppositely charged pyrenetetrasulfonate in aqueous solution. Water soluble ionenes were prepared via Menschutkin reaction from 1‐4‐diazabicyclo[2.2.2]octane (DABCO) and dibromoalkenes. UVVis results revealed that PY molecules bind to ionenes in a cooperative process due to π–π interaction. Size and structure of the particles vary in dependence of inter‐charge distance on the ionene backbone. Stable spherical dye–ionene assemblies with radii between 50 and 200 nm have been obtained with one polyelectrolyte (PD4), while this was not possible with a different polyelectrolyte (PD6) or in either case at polyelectrolyte excess. It was possible to deposit the fluorescent polyelectrolyte–dye aggregates onto mica surfaces.magnified image