Fig. 3: Fast second reduction kinetics and less homogeneous Au NCs.
From: Critical roles of metal–ligand complexes in the controlled synthesis of various metal nanoclusters
a, d UV–vis absorption spectra, b, e MALDI-TOF mass spectra in the linear mode, and (c, f), Digital photographs of Au NCs during the second reduction using precursors obtained applying the 1:1, 15 s (from 0 m of second reduction, light brown to 3 h of second reduction, bold brown), and the 1:2, 15 s conditions (from 0 m of second reduction, light blue to 3 h of second reduction, bold blue), respectively. Dashed lines in UV–vis absorption and mass spectra indicate the evidence of Au25 NCs. Arrows in (a) indicate the decreasing fraction of Au25 NCs with increasing second reduction time, while those in (d) indicate the increasing fraction of Au25 NCs with increasing second reduction time. Arrows in (b, e) indicate the existence of Au NCs larger than Au25. g Reaction mechanism scheme when the degree of the first reduction is low (Au: yellow, S: magenta, non-sulfur anions: lime). Source data are provided as a Source Data file.
