Diaminomaleonitrile-based Schiff bases: aggregation-enhanced emission, red fluorescence, mechanochromism and bioimaging applications

Here we report the synthesis of two diaminomaleonitrile-based Schiff bases with a donor-acceptor structure and an aggregation-enhanced emission feature. By changing the alkyl chain length in the donor unit, a red-emitting material with remarkable mechanochromic properties and applications in bioimaging was generated due to the J-aggregate formation in the solid state.