Au38(SR)24 is one of the most extensively investigated gold nanomolecules along with Au25(SR)18 and Au144(SR)60. However, so far
it has only been prepared using aliphatic-like ligands, where R = –SC6H13, -SC12H25 and –SCH2CH2Ph. Au38(SCH2CH2Ph)24 when
reacted with HSPh undergoes core-size conversion to Au36(SPh)24, and existing literature suggest that Au38(SPh)24 cannot be synthesized.
Here, contrary to prevailing knowledge, we demonstrate that Au38(SPh)24 can be prepared if the ligand exchanged conditions
are optimized, without any formation of Au36(SPh)24. Conclusive evidence is presented in the form of MALDI-MS, ESI-MS characterization,
and optical spectra of Au38(SPh)24 in a solid glass form showing distinct differences from that of Au38(S-aliphatic)24. Theoretical
analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au38(SPh)24 is comparable
to that of its aliphatic analogues, but results from different physical origins, with a significant component of ligand-ligand attractive
interactions.
Revised: April 25, 2017 |
Published: April 6, 2017
Citation
Rambukwella M., S. Burrage, M. Neubrander, O. Baseggio, E. Apra, M. Stener, and A. Fortunelli, et al. 2017.Au38(SPh)24: Au38 Protected with Aromatic Thiolate Ligands.The Journal of Physical Chemistry Letters 8, no. 7:1530–1537.PNNL-SA-122665.doi:10.1021/acs.jpclett.7b00193