pi-Conjugated diimidazolium salts: rigid structure to obtain organized materials

Phenylene ethynylene based diimidazolium salts differing in the alkyl chain length borne on theimidazolium ion and anion nature were synthesized. Their properties were studied both in solution andin the solid state. Salts obtained were able to aggregate in organic solvent solution. Aggregate formationwas studied by performing concentration dependent measurements using UV-vis, fluorescence andResonance Light Scattering. Furthermore, features of the aggregates were also investigated in the solidstate by means of fluorescence and Scanning Electron Microscopy measurements. Finally, DensityFunctional Theory calculations were performed to obtain insights into the interaction geometry in thesalts investigated. Data collected evidence that aggregation processes are affected by a combinedaction of different factors derived from the nature of the salt and solvent. The above features alsoinfluence the morphology of the aggregates as well as the ability of their thin films to give blueemission. On the whole, information gained could represent a useful starting point for applications ofthese salts in the optoelectronic field among others.