| Literature DB >> 26276593 |
Chanaka Kumara1, Christine M Aikens2, Amala Dass1.
Abstract
The atomic arrangement of Au and Ag atoms in Au25-xAgx(SR)18 was determined by X-ray crystallography. Ag atoms were selectively incorporated in the 12 vertices of the icosahedral core. The central atom and the metal atoms in the six [-SR-Au-SR-Au-SR-] units were exclusively gold, with 100% Au occupancy. The composition of the crystals determined by X-ray crystallography was Au18.3Ag6.7(SCH2CH2Ph)18. This composition is in reasonable agreement with the composition Au18.8Ag6.2(SCH2CH2Ph)18 measured by electrospray mass spectrometry. The structure can be described in terms of shells as Au1@Au5.3Ag6.7@6×[-SR-Au-SR-Au-SR-]. Density functional theory calculations show that the electronic structure and optical absorption spectra are sensitive to the silver atom arrangement within the nanocluster.Entities:
Keywords: Au25; alloy nanomolecules; gold−silver alloy; monolayer protected clusters
Year: 2014 PMID： 26276593 DOI： 10.1021/jz402441d
Source DB: PubMed Journal: J Phys Chem Lett ISSN： 1948-7185 Impact factor: 6.475