Templated Atom‐Precise Galvanic Synthesis and Structure Elucidation of a [Ag24Au(SR)18]− Nanocluster. (27th November 2015)

• Record Type: Journal Article
• Authors: Bootharaju, Megalamane S.; Joshi, Chakra P.; Parida, Manas R.; Mohammed, Omar F.; Bakr, Osman M.
• Is Part Of: Angewandte Chemie. Volume 128:Number 3(2016)
• Page Start: 934
• Page End: 938
• Publication Date: 2015-11-27
• Subjects: Gold -- Legierungen -- Metallaustausch -- Silber -- Strukturaufklärung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201509381
• Languages: English
• ISSNs: 0044-8249

Abstract

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 [Ag24 Au(SR)18 ] − cluster (SR: thiolate) using a pure [Ag25 (SR)18 ] − cluster as a template. Conversely, the direct synthesis of Ag24 Au cluster leads to a mixture of [Ag25− x Au x (SR)18 ] −, x =1–8. Mass spectrometry and crystallography of [Ag24 Au(SR)18 ] − reveal the presence of the Au heteroatom at the Ag25 center, forming Ag24 Au. 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 Ag24 Pd clusters with same ligand and structural framework, providing new insights into the modulation of cluster properties with dopants at the single‐atom level.