A new reductant in gold cluster chemistry gives a superatomic gold gallium cluster.

2021 ◽  
Author(s):  
Andreas Schnepf ◽  
Andre Clayborne ◽  
Florian Fetzer ◽  
Nia Pollard ◽  
Adebola Adeagbo ◽  
...  
Keyword(s):  
Gold Cluster ◽  
Reducing Agents ◽  
Cluster Chemistry ◽  
Gold Chemistry ◽  
Low Valent

The low valent gallium(I) compound GaCp was primarily used in gold cluster chemistry to synthesize the superatomic cluster [(PPh3)8Au9GaCl2]2+, complementing the borane-dominated set of reducing agents in gold chemistry, opening...

Some theoretical and structural aspects of gold cluster chemistry

1982 ◽  
Vol 308 (1501) ◽  
pp. 75-83 ◽  
Keyword(s):  
Gold Cluster ◽  
Effective Interaction ◽  
Gold Atom ◽  
Cluster Compounds ◽  
Molecular Orbital Calculations ◽  
Cluster Chemistry ◽  
Theoretical Concepts ◽  
Simplified Approach ◽  
Wide Range ◽  
Semi Empirical

The bonding in tertiary phosphine cluster compounds of gold is sufficiently straightforward to permit an effective interaction between theoretical concepts developed from semi-empirical molecular orbital calculations and synthetic and structural chemistry. At the simplest conceptual level the isolobal nature of the Au(PR 3 ) fragment and either the CH 3 or H radicals provides a basis for understanding the structures of a wide range of homonuclear and heteronuclear clusters, e.g. Os 3 (CO) 10 - H(AuPPh 3 ) and (OG) 5 VAu 3 (PPh 3 ) 3 . However, this simplified approach neglects some secondary gold-gold interactions between adjacent gold atoms, which arise from the availability of the higher-lying gold 6p orbitals. In low-nuclearity clusters tetrahedral fragments, which permit the effective formation of four-centre two electron bonds between the Au(PR 3 ) fragments, are preferred to larger deltahedra. In higher-nuclearity clusters the stabilities of the clusters depend on the presence of a central gold atom that provides strong radial gold-gold bonding. The relative importance of the radial and tangential components to the total bonding has been effectively demonstrated by a structural comparison of alternative Au 9 (PR 3 )3/8+ clusters. The predictive capability of the theoretical approach has been demonstrated by the synthesis and structural characterization of the icosahedral cluster [Au 13 Cl 2 (PMe 2 Ph) 10 ]3+.

New horizons in low oxidation state group 2 metal chemistry

2021 ◽  
Author(s):  
Sjoerd Harder ◽  
Bastian Rösch
Keyword(s):  
Oxidation State ◽  
State Of The Art ◽  
Reducing Agents ◽  
Metal Chemistry ◽  
New Horizons ◽  
Low Valent ◽  
Low Oxidation State ◽  
Group 2 ◽  
State Group

Since the seminal report on Mg in the +I oxidation state in 2007, low-valent complexes featuring a MgI-MgI bond developed from trophy molecules to state-of-the-art reducing agents. Despite increasing interest...

Gold cluster chemistry with the tin nucleophile stanna-closo-dodecaborate

2010 ◽  
Vol 75 (9) ◽  
pp. 963-970 ◽  
Author(s):  
Hartmut Schubert ◽  
Fritz-Robert Küchle ◽  
Lars Wesemann
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Gold Cluster ◽  
Mixed Valence ◽  
Gold Complex ◽  
Reaction Products ◽  
Cluster Chemistry ◽  
X Ray ◽  
X Ray Crystallography

The tin nucleophile [SnB11H11]2– reacts with the gold cluster [Au9(PPh3)8][NO3]3 under formation of the tin–gold complex [Au8(PPh3)7(SnB11H11)] (1). In reaction with four equivalents of the heteroborate a mixed valence tetrahedral gold cluster [Au4(PPh3)4(SnB11H11)2]2– with two edge bridging tin ligands was isolated. The reaction products were characterized by elemental analysis, NMR spectroscopy and single crystal X-ray crystallography.

High-resolution gold labeling

1993 ◽  
Vol 51 ◽  
pp. 330-331
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya ◽  
Kyra Carbone ◽  
Martha Simon ◽  
Beth Lin ◽  
...  
Keyword(s):  
Dihydrofolate Reductase ◽  
Polypeptide Chain ◽  
External Surface ◽  
Gold Cluster ◽  
Macromolecular Complex ◽  
Gold Compound ◽  
Central Cavity ◽  
Chain Folding ◽  
E Coli ◽  
Chaperonin Groel

A recently developed 1.4 nm gold cluster has been found to be useful in labeling macromolecular sites to 1-3 nm resolution. The gold compound is organically derivatized to contain a monofunctional arm for covalent linking to biomolecules. This may be used to mark a specific site on a structure, or to first label a component and then reassemble a multicomponent macromolecular complex. Two examples are given here: the chaperonin groEL and ribosomes.Chaperonins are essential oligomeric complexes that mediate nascent polypeptide chain folding to produce active proteins. The E. coli chaperonin, groEL, has two stacked rings with a central hole ∽6 nm in diameter. The protein dihydrofolate reductase (DHFR) is a small protein that has been used in chain folding experiments, and serves as a model substrate for groEL. By labeling the DHFR with gold, its position with respect to the groEL complex can be followed. In particular, it was sought to determine if DHFR refolds on the external surface of the groEL complex, or whether it interacts in the central cavity.

Methods for the Concentration of Bovine Ac-Globulin (Factor V)

1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers
Keyword(s):  
Room Temperature ◽  
Barium Carbonate ◽  
Deae Cellulose ◽  
Reducing Agents ◽  
Factor V ◽  
Isoelectric Precipitation ◽  
Stabilizing Agent ◽  
Bovine Plasma ◽  
The Stability

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.

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