One pot synthesis of fluorescent π-conjugated materials: immobilization of phenylene–ethynylene polyelectrolytes in silica confined ionogels

Phenylene–ethynylene monomer and copolymer bearing pendant imidazolium groups were synthesized in order to obtain luminescent entities highly soluble in ionic liquids (ILs). Their stabilities under non-aqueous sol–gel conditions (i.e. using formic acid) allowed their incorporation into silica in the form of ionogels. This was performed in a one step synthesis and the resulting materials were found to be easily processable as monoliths and showed interesting luminescent properties. Given the high solubility of 2,4-dinitrotoluene in the investigated IL, (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), the relevance of these ionogels as luminescent sensors was tested.