Effect of alkyl groups on emission properties of aggregation induced emission active N-alkyl arylaminomaleimide dyes

Aggregation induced emission (AIE) active N -alkyl aminomaleimide dyes with various kinds of N -alkyl groups were synthesized in a one pot process. The synthesized dyes exhibited different emission behaviors depending on the chemical structure of the N -alkyl group, although they had no direct contribution to the π-conjugated system. Chain length, hydroxyl group and branching structure were important in the emission properties such as quantum yield and emission wavelength. Furthermore, it was found that one of the dyes showed mechanochromism; the green emission of crystal samples turned to blue emission after grinding. Single crystal X-ray diffraction analysis revealed that the surrounding around the luminophore was dominant in the emission behaviors.