Anderson ID, Wang Y, Aikens CM, Ackerson CJ. An ultrastable thiolate/diglyme ligated cluster: Au
20(PET)
15(DG)
2.
NANOSCALE 2022;
14:9134-9141. [PMID:
35723454 DOI:
10.1039/d2nr02426h]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
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 gas phase. Thermal analysis shows the cluster degrades at 156 °C, whereas the similar Au20(PET)16 cluster degrades at 125 °C, representing markedly increased thermal stability. A combination of NMR spectroscopy and computational modeling suggests that the diglyme molecules bind in a tridentate manner for this cluster, resulting in a binding energy of 35.2 kcal mol-1 for diglyme, which is comparable to the value of ∼40 kcal mol-1 for thiolates. IR and optical spectroscopies show no evidence of assembly of this cluster, in contrast to Au20(PET)15(DG), which readily assembles into dimeric species, which is consistent with a tridentate binding motif. Evidence for stacking among Au-bound and non-bound diglyme molecules is inferred from thermal and mass analysis.
Collapse