Templated Atom‐Precise Galvanic Synthesis and Structure Elucidation of a [Ag24Au(SR)18]− Nanocluster |
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| Authors: | Dr Megalamane S Bootharaju Chakra P Joshi Dr Manas R Parida Prof Omar F Mohammed Prof Osman M Bakr |
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| Institution: | Division of Physical Sciences and Engineering, Solar and Photovoltaics Engineering Research Center (SPERC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia |
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| Abstract: | Synthesis of atom‐precise alloy nanoclusters with uniform composition is challenging when the alloying atoms are similar in size (for example, Ag and Au). A galvanic exchange strategy has been devised to produce a compositionally uniform Ag24Au(SR)18]? cluster (SR: thiolate) using a pure Ag25(SR)18]? cluster as a template. Conversely, the direct synthesis of Ag24Au cluster leads to a mixture of Ag25?xAux(SR)18]?, x=1–8. Mass spectrometry and crystallography of Ag24Au(SR)18]? reveal the presence of the Au heteroatom at the Ag25 center, forming Ag24Au. The successful exchange of the central Ag of Ag25 with Au causes perturbations in the Ag25 crystal structure, which are reflected in the absorption, luminescence, and ambient stability of the particle. These properties are compared with those of Ag25 and Ag24Pd clusters with same ligand and structural framework, providing new insights into the modulation of cluster properties with dopants at the single‐atom level. |
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| Keywords: | galvanic exchange alloys gold silver structure determination |
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