Selenolate-Protected Au₃₈ Nanoclusters: Isolation and Structural Characterization

Abstract

We report the isolation and structural characterization of dodecaneselenolate-protected Au 38 clusters (Au 38 (SeC 12 H 25 ) 24 ). These clusters were synthesized via the reaction of phenylethanethiolate-protected Au 38 clusters (Au 38 (SC 2 H 4 Ph) 24 ) with didodecyldiselenide ((C 12 H 25 Se) 2 ).Characterization of the product by mass spectrometry and thermogravimetric analysis confirmed that highly pure Au 38 (SeC 12 H 25 ) 24 had been obtained. The electronic and geometrical structures, bonding characteristics, and stability of the Au 38 (SeC 12 H 25 ) 24 clusters were assessed using extended Xray fine structure and X-ray absorption near edge structure measurements, optical absorption spectroscopy, electrochemical measurements, and stability testing.

Bonding properties of thiolate-protected gold nanoclusters and structural analogs from X-ray absorption spectroscopy

“…An understanding of the Au local structure was extended in this work by employing a fourshell EXAFS fit following a previously established fitting approach for Au 25 (SR) 18 NCs [40]. At 50 K, Au-Se and core Au-Au bond distances from EXAFS fitting were consistent with Kurashige et al [68]. The second Au-Au scattering shell indicated that the Au-Au interactions on the surface of the Au 13 core were comparable to the thiolateprotected Au 25 .…”

“…Au L 3 -edge and Se K-edge XAS results were used to investigate the local structure and temperature-dependent bonding properties of Au 25 (SeR) 18 NCs with the XAS data collected presented in Figure 8. Similar to the dodecanceselenolate-Au 25 and -Au 38 studied by Kurashige et al [68], Au-Se bonding produced a broad scattering feature that partially overlapped with Au-Au scattering. Comparing EXAFS oscillations in the k-space at 50 K (Figure 8, top left), late k-space (8-13 Å -1 ) oscillations were significantly more intense for the selenolateprotected Au 25 , potentially from more tightly ordered Au-Au bonding.…”

“…The isolation and structural characterization of dodecaneselenolateprotected Au 38 clusters (Au 38 (SeC 12 H 25 ) 24 ) was reported first by Kurashige et al [68]. In this work, the local structure of Au 38 (SeR) 24 was mainly characterized by Au L 3 -edge EXAFS, as shown in Figure 7.…”

Understanding Ligand-Exchange Reactions on Thiolate-Protected Gold Clusters by Probing Isomer Distributions Using Reversed-Phase High-Performance Liquid Chromatography

“…Similar results were also obtained for the reaction between Au 24 Pd(SC 2 H 4 Ph) 18 and (C 12 H 25 Se) 2 (Figures 8(b) and S17). The reaction of Au n (SR) m clusters with diselenide is often used for the synthesis of Au n (SeR) m clusters, 56,57 but little is known about its mechanism. As shown in Figure 8 Figure S18).…”

A site-specific comparative study of Au102 and Au25 nanoclusters using theoretical EXAFS and l-DOS

“…1,[14][15][16][17][18][19][20] In addition to X-ray crystallography, X-ray absorption fine structure (XAFS) techniques have also been found useful to probe the local environment and electronic properties of Au nanoclusters. 8,17,[21][22][23][24][25][26][27][28] Two of these crystallographically determined systems, the phenylethanethiol-capped Au25(SCH2CH2Ph)18 -system (referred to as Au25), 15 and the mercaptobenzoic acid-capped Au102(MBA)44 (referred to as Au102), 1 exhibit similar surface organization ( Figure 1). In the Au25 system, the phenylethanethiol ligands bind to surface gold atoms and form six "double-staples" surrounding a 13-atom icosahedral core, stabilizing the cluster.…”