Ionic self-assembly and red-phosphorescence properties of a charged platinum(II) 8-quinolinol complex associated with ammonium-based amphiphiles

Abstract

A series of ionic associates based on the platinum(II) chelate of 5-sulfo-8-quinolinol, [Pt(qS)], and ammonium-based amphiphiles is described. At variance with the prototypical neutral complex Pt(q) (q=8-quinolinol), these dianionic fluorophores, functionalized at the periphery with sulfonate groups, can be associated by the ionic self-assembly approach with various ammonium cations, such as (HC)MeN (n=12, 16, 18) or complex ammonium cations carrying three C carbon chains (n=12, 14, 16) and an additional amide group. Investigations of their luminescence properties in solution, in the solid state, and, when possible, in thin films revealed that the phosphorescence properties in condensed phases are directly correlated to intermolecular interactions between the luminescent [Pt(qS)] centers. Of particular interest is also the formation of a columnar liquid-crystalline phase around room temperature (between -25 and +180 C), as well as the very good film-forming ability of some of these fluorophores from organic solvents.