Copyright (2017), Wiley-VCH Verlag GmbH & Co. KgaA. (e) Molecular structure of PPD derivatives, where the benzene-fused PPD exhibits AIE characteristics while the PPD with two thiophene fused leads to ACQ phenomenon. Reproduced from Ref. with permission. Copyright (2021), The Royal Society of Chemistry. (f), (g) Molecular structures and photophysical properties of coumarin derivatives CD-7 and CD-5, where CD-7 exhibits AIE behavior while CD-5 displays ACQ behavior. Reproduced from