The fluorescence lifetime (τs) of SCPP [8] in THF was measured by time-resolved fluorescence decay using the timeresolved photoluminescence (TRPL) technique. The emission lifetime of SCPP [8] was determined to be τ = 4.23 ns at 475 nm by mono-exponential decay fitting when excited at 390 nm (Figure ). Traditional organic luminescent materials can emit efficiently either in dilute solution or in the aggregated state. However, an interesting phenomenon was found when we studied the luminescence behavior of SCPP [8]. Upon excitation with 365 nm UV light, SCPP [8] in THF solution emitted cyan fluorescence, while the powder sample exhibited an orange fluorescence. The powder and crystal of SCPP [8] were orange under daylight (Figure ). All these observations indicated that SCPP [8] has different emission properties upon aggregation with possible AIE effect. The luminescent properties of the SCPP [8] were further investigated in H2O/THF mixtures with different water fractions (fw), in which THF is a good solvent and water is a poor solvent. The fluorescence intensity of SCPP[8] maximized at ~475 nm decreased as the water fraction was increased, showing an obvious quenching effect due to aggregation. An interesting phenomenon was observed at fw > 60 vol %. A new emission band appeared at ~577 nm and the fluorescence intensity was further enhanced when a higher content of water was added, which could be ascribed to the obvious AIE effect (Figure ). Meanwhile, the maximum emission wavelength was redshifted by 102 nm, from 475 nm to 577 nm. For comparison, when [8]CPP was dissolved in THF, the dilute solution showed strong yellow luminescence. With the gradual increase in the fraction of water, the emission became weakened and no any AIE effect was observed. At fw = 80 vol % and fw = 90 vol %, the emission was significantly quenched due to severe aggregate formation, indicating a typical ACQ effect (Figure and Figure ). For comparison, the emissive properties of our previously reported [10]CPP-based bismacrocycle SCPP [10] with larger rings were also investigated in H2O/THF mixtures (Figure ). However, SCPP [10] only showed some AIE effect with no dual-emissive property and no such significant redshift in emission.