Regulation of aggregation-induced emission behaviours and mechanofluorochromism of tetraphenylethene through different oxidation states of sulphur moieties

Abstract

Different oxidation states of sulphur can be used to regulate the aggregation-induced emission (AIE) behaviours and reversible mechanofluorochromic properties of tetraphenylethene (TPE) derivatives. With the introduction of oxygen atoms via the oxidation of thioether-containing TPE, the AIE properties and aggregation turn-on threshold of AIE luminogens (AIEgens) could be regulated. The single crystal structures revealed that weak intermolecular interactions might reduce the emission intensities of 1 in the crystalline phase. In addition, one sulphone-containing TPE derivative 3 demonstrated polymorphism-dependent fluorescence of different colours due to different packing modes, resulting in tricolored emission switching.