{Reference Type}: Journal Article {Title}: Light-Regulated Nucleation for Growing Highly Uniform Single-Crystalline Microrods. {Author}: Sun L;Gong Y;Che Y;Ji H;Liu B;Che Y;Zhao J; {Journal}: Angew Chem Int Ed Engl {Volume}: 63 {Issue}: 20 {Year}: 2024 May 13 {Factor}: 16.823 {DOI}: 10.1002/anie.202402253 {Abstract}: We report a light-irradiation method to control the synchronous nucleation of a donor-acceptor (D-A) fluorophore for growing highly uniform single-crystalline microrods, which is in sharp contrast to the prevailing methods of restricting spontaneous nucleation and additionally adding seeds. The D-A fluorophore was observed to undergo photoinduced electron transfer to CrCl3, leading to the generation of HCl and the subsequent protonation of the D-A fluorophore. By intensifying photoirradiation or prolonging its duration, the concentration of protonated D-A fluorophores can be rapidly increased to a high supersaturation level. This results in the formation of a controlled number of nuclei in a synchronous manner, which in turn kickstart the epitaxial growth of protonated D-A fluorophores towards uniform single-crystalline microrods of controlled sizes. The light-regulated synchronous nucleation and uniform growth of microrods are a unique phenomenon that can only be achieved by specific Lewis acids, making it a novel probing method for sensitively detecting strong Lewis acids such as chromium chloride.