scholarly journals Front Cover: Ligand Migration from Cluster to Support: A Crucial Factor for Catalysis by Thiolate‐protected Gold Clusters (ChemCatChem 23/2018)

ChemCatChem ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 5337-5337 ◽  
Author(s):  
Bei Zhang ◽  
Annelies Sels ◽  
Giovanni Salassa ◽  
Stephan Pollitt ◽  
Vera Truttmann ◽  
...  
Keyword(s):  
Gold Clusters ◽  
Front Cover ◽  
Ligand Migration

scholarly journals Ligand Migration from Cluster to Support: A Crucial Factor for Catalysis by Thiolate‐protected Gold Clusters

ChemCatChem ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 5341-5341
Author(s):  
Bei Zhang ◽  
Annelies Sels ◽  
Giovanni Salassa ◽  
Stephan Pollitt ◽  
Vera Truttmann ◽  
...  
Keyword(s):  
Gold Clusters ◽  
Ligand Migration

scholarly journals Ligand Migration from Cluster to Support: A Crucial Factor for Catalysis by Thiolate‐protected Gold Clusters

ChemCatChem ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 5372-5376 ◽  
Author(s):  
Bei Zhang ◽  
Annelies Sels ◽  
Giovanni Salassa ◽  
Stephan Pollitt ◽  
Vera Truttmann ◽  
...  
Keyword(s):  
Gold Clusters ◽  
Ligand Migration

Crystal structure images of large gold clusters and growing crystals by HRTEM

1984 ◽  
Vol 42 ◽  
pp. 428-429
Author(s):  
L.R. Wallenberg ◽  
J.-O. Bovin ◽  
G. Schmid
Keyword(s):  
Crystal Structure ◽  
Nucleation And Growth ◽  
Close Packing ◽  
Gold Clusters ◽  
Molecular Weight Determination ◽  
Growth Mechanisms ◽  
Starting Point ◽  
Different Types ◽  
Nucleation And Growth Mechanisms ◽  
Points Of View

Metallic clusters are interesting from various points of view, e.g. as a mean of spreading expensive catalysts on a support, or following heterogeneous and homogeneous catalytic events. It is also possible to study nucleation and growth mechanisms for crystals with the cluster as known starting point.Gold-clusters containing 55 atoms were manufactured by reducing (C6H5)3PAuCl with B2H6 in benzene. The chemical composition was found to be Au9.2[P(C6H5)3]2Cl. Molecular-weight determination by means of an ultracentrifuge gave the formula Au55[P(C6H5)3]Cl6 A model was proposed from Mössbauer spectra by Schmid et al. with cubic close-packing of the 55 gold atoms in a cubeoctahedron as shown in Fig 1. The cluster is almost completely isolated from the surroundings by the twelve triphenylphosphane groups situated in each corner, and the chlorine atoms on the centre of the 3x3 square surfaces. This gives four groups of gold atoms, depending on the different types of surrounding.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

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