Gold cluster

Belt gold atoms which form a puckered hexagonal or octagonal belt around the center gold atom 

Distal gold atoms which appear above or below the belt gold atoms 

The topology of the centered gold clusters can be considered to be either spherical or toroidal depending on whether the center gold atom uses a nine-orbital spherical sp d  

The following features of centered gold clusters make their systematics very different from other metal cluster compounds such as metal carbonyl clusters  

13 total gold atoms is generally based on an undistorted icosahedral fragment which has a large enough volume for the center gold atom. 

The disproportionation reactions for dinuclear gold(II) complexes to give gold (III)/gold(I) derivatives are known and well represented. On the contrary only one 

Since the most abundant gold(II) complexes belonging to the Au2 formulation have been discussed above, now we will refer to nudearity higher than two. This includes complexes with more than two gold atoms in the molecule or with other metals in their composition in addition to the gold centers (see Table 3.15). 

Herein we describe the synthesis and characterization of small-size homonuclear gold cluster compounds with a nuclearity ranging from 3 to 39 gold atoms. These types of dusters are usually characterized through definitive structural techniques such as single-crystal X-ray diffraction, enabling in-depth study of the structural arrangements found in the solid state. 

This section is divided into two main subsections. The first describes the synthesis and characterization of phosphine-stabilized gold clusters. The second focuses on the synthesis and characterization of thiol-stabilized gold clusters and the study of other stabilizers such as arsines or boranes are described. 

Modern Supramolecular Gold Chemistry Gold-Metal Interactions and Applications. Edited by Antonio Laguna 

Copyright 2008 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-32029-5 

Synthesis and Structural Characterization of Phosphine-Stabilized Cold Clusters 

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Valden M, Lai X and Goodman D W 1998 Onset of catalytic activity of gold clusters on titania with the appearance of nonmetallic properties Science 281 1647... 

AUg, Au.. and Au.13, and their cations gold clusters with 6-13 s-electrons J. Chem. Rhys. 101 3506... 

Schmid G ef a/1981 Au33(PCgHg)3). 2Clg a gold cluster of an exceptional size Chem. Ber. 114 3634... 

Figure 4.46 Orbital interaction diagram for the Au6C framework in (H3PAu)6C2+showing the important bonding interactions of the carbon 2s and 2p orbitals with the MOs of the gold cluster. (Reprinted from J. Organomet. Chem., 384, 405, 1990, with kind permission from Elsevier Science S.A., P.O. Box 564, 1001 Lausanne, Switzerland.)...

Formation of the Group-IB or -IIB-Group-IB or -MB Metal Bonds 343 8.2.1. in Gold Cluster Compounds... 

Gold clusters can be synthesized by three methods reduction of Au(I) compounds, evaporation of Au metal and conversions of Au clusters. 

Sodium borohydride reductions of gold(I) complexes give Au clusters at RT if sodium borohydride in ethanol is dropped slowly into a suspension of the Au(I) complex in the same solvent. The immediate coloring of the reaction mixture (mostly red), even after only a few drops of the borohydride have been added, indicates fast formation of Au clusters. In view of the complicated composition of these compounds the fast formation is surprising. The use of H2 and CO with HjO as reducing agents in the synthesis of gold clusters has been described (see Table 1, Method A, 8.2.2.2). 

In recent years a great number of mixed metal-gold clusters have been reported " . 

Gold clusters can be prepared that contain species other than the Au, Aug, Au, and AU, described in 8.2.1. There is little strategie method in the synthesis, products often arising by chance. 

Heteronuclear Gold Cluster Compounds D. Michael P. Mingos and Michael J. Watson... 

Grinding conditions are modified by the nature of supports. Gold clusters with a diameter of 1.5 nm were obtained on an aluminum-containing porous coordination polymer by grinding in an agate mortar in air for 20 min, followed by the reduction in a stream of H2 in N2 at 120°C for 2 h ]50]. In contrast, ball milling is favorable... 

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