The aforementioned research and development of AIE properties for COT/COTh provide us with some insights. The flexibility of cyclic structures that conform to Baird's rule is influenced by non-aggregated factors such as temperature, viscosity, and pressure, which constrain the relative proportions of planar and curved molecular configurations in the solution, thus manifesting restricted vibrational-enhanced emission. In fact, considering that Baird's rule applies to 8π electron structures, do other cyclic structures that satisfy the 8π electron structure also exhibit AIE properties? For example, when atoms such as N, S, and O substituted to conjugated ring which proved lone pair electrons for the π orbitals, therefore, theoretically, heptatomic ring with one heteroatom or a hexatomic ring with two heteroatoms (with symmetric distribution that not affecting the original excited-state configuration) could also design as BPAC type RIV molecules. with permission. Copyright (2015), Wiley-VCH Verlag GmbH & Co. KGaA.