Quantitatively Monitoring the Size-Focusing of Au Nanoclusters and Revealing What Promotes the Size Transformation from Au44(TBBT)28 to Au36(TBBT)24

Size-focusing is a well-recognized process and widely employed for the synthesis of atomically monodisperse metal nanoclusters. However, quantitatively monitoring the size-focusing of Au nanoclusters has not been achieved yet, and the in-depth understanding of the size focusing is far from completed. Herein, we introduce a facile, cheap, and powerful tool, preparative thin-layer chromatography (PTLC), to quantitatively track the size-focusing process, to reveal that mainly similar to 3 nm nanoparticles promote the transformation from Au-44(TBBT)(28) to Au-36(TBBT)(24) (where TBBT is 4-tert-butylbenzenethiolate) and to improve the syntheses of Au-44(TBBT)(28) and Au-36(TBBT)(24). Our work further demonstrates the usefulness of PTLC in nanocluster research and advances one step toward understanding the size-focusing process of nanoclusters.