Fig. 2: Analysis of aromatic thiolates in the protective shell.
a 1H NMR spectrum of Au138(SR)48 in chloroform-d. b 1H–1H COSY spectrum depicting the correlations between aromatic protons in four sets of 2,4-DMBT ligands. Pink and gray circles highlight protons significantly influenced by π–π stacking and C–H···π interactions, respectively. Long-range couplings between protons at the 3- and 5-positions of aromatic rings are demonstrated by black circles. c Schematic illustration of 12 [–SR–Au–SR–] staples in two separate protective units with assigned signals of all aromatic protons. d Enantiomeric distributions of aryl groups on the [–SR–Au–SR–] staples viewed from the [100] direction. The thin and thick circles with three fan blades inside depict the protective units with cis and trans staple motifs, respectively. The directions of the blue fan blades reflect the orientations of the aryl groups containing C–H···π interactions; the red and gray circles represent the aryl groups on the periphery of the protective units from two enantiomers of Au138(SR)48. Color labels in the chemical structures: Au, green and orange; S, yellow; C, red, blue, and gray; H, white.
