One platform solid multicolour emission of terthiophene compounds controlled by mixed self-assembly

Via the mixed self-assembling procedure, solid multicolour emission materials based on an amphiphilic terthiophene compound are obtained from a unimolecular platform. Upon controlling the concentration of the cationic surfactant dodecyltriethyl ammonium bromide (DEAB) in the precipitate-monomer equilibrium system of the terthiophene compound TTC4L, mixed self-assembly of TTC4L-DEAB results in diverse structures (including plates, spheres, and needles) with different emission colours. The multicolour emissions are triggered by the different distances between the terthiophene groups in these mixed self-assemblies. Each distance corresponds to a specific molecular state of terthiophene groups, so that emissions corresponding to the monomers, excimers, and aggregates are obtained. Upon variation of the ratio of DEAB and TTC4L, the relative fraction of emissions corresponding to the monomers, excimers, and aggregates of TTC4L changes. This approach may act as a simple method to control the stacking mode of the oligothiophene group which is anticipated to realize unimolecular-platform multicolour emissions.