An ultrastable thiolate/diglyme ligated cluster: Au₂₀(PET)₁₅(DG)₂

Abstract

The synthesis and characterization of an Au20(PET)15(DG)2 (PET=phenylethane thiol; DG=Diglyme) cluster is reported. Mass spectrometry reveals this as the first diglyme ligated cluster where diglyme ligands survive ionization into the...

Effects of Diglyme on Au Nanocluster Formation: Mechanism, 1H NMR, and Bonding

“…We note that in the experiment, diglyme is present in great excess as a solvent; Le Chatelier’s principle will likely aid in the formation of the diglyme-bound AuCl 3 species. In this work, we only considered the binding of a single diglyme to the gold systems, in part because only one or at most two diglyme species have ligated experimental nanoclusters, − although future work could consider the binding of additional diglyme molecules.…”

“…Protons that are oriented near gold and chloride will shift downfield, whereas protons that are pointed toward the PET group will move upfield. It was found experimentally in the diglyme-protected Au 20 (PET) 15 dg 2 system that some of the protons on diglyme move downfield significantly, and theoretical results suggest that these protons are located near the gold atoms in the nanocluster …”

“…The 1 H NMR spectra of the pure diglyme molecule was investigated previously and the theoretical chemical shifts lie in the range from 3.26 to 3.98 ppm. 19 In (AuCl 3 )dg (Figure 5A), AuCl 3 is a gold−chloride moiety with a +3 charge state for gold. The calculated 1 H NMR spectrum has chemical shifts that range from 3.35 to 4.95 ppm (Table 3).…”

“…It was found experimentally in the diglyme-protected Au 20 (PET) 15 dg 2 system that some of the protons on diglyme move downfield significantly, and theoretical results suggest that these protons are located near the gold atoms in the nanocluster. 19 C. Chemical Bonding Analysis. Because the interaction between diglyme and the Au-containing moieties is of significant interest in this work, the metal−oxygen bond in the molecular system is investigated using the ETS-NOCV chemical bonding theory.…”

“…The B–S method starts with a Au­(III) complex (such as HAuCl 4 ) and follows with a two-solvent phase reduction to synthesize gold–thiolate nanoclusters . Several modifications to the Brust–Schiffrin methods (i.e., changing the solvent, changing from two-phase to one-phase reactions) were then studied to refine the reaction process. , Recently, a mixture of diglyme (dg) and tetrahydrofuran (THF) solvents was applied to the gold–thiolate nanocluster self-assembly process, and diglyme can be observed as a ligand in the final generated product. − Diglyme was found to yield a gold–thiolate nanocluster dimer as well, which indicates that diglyme can mediate the gold nanoparticle assembly process . Moreover, a Au 20 (SR) 15 –diglyme system was also found experimentally in which diglyme mediates the dimerization of two nanoclusters to yield a photoluminescent cluster with a very high quantum yield .…”