Coinage metals Silver, Gold

When thiols with varying chain lengths, such as Cg-, Cio-, Ci2- and Ci6- are used, we observe very interesting trends [47]. First, all the colloids under reflux conditions display a strong reddish color. Nanoparticles, especially those of coinage metals like gold and silver, display striking colors... 

On the whole, two coordination is found for the lower oxidation state (I) of the coinage metals (copper, gold, silver) and among their isoelectronic neighbors [e.g., Hg(OH2)2), Tl(OH2)2 ]. 

Of all the ancient metallic artifacts that have been left from antiquity, coins are among the most numerous. Since ancient times coins have generally been made from coinage metals or, mostly, from coining alloys, whose chemical and physical properties and economic qualities make them suitable to be used for this purpose. Until the twentieth century, gold, silver, copper, and their alloys were practically the only metals from which coinage was made. All these metals and alloys have the following properties ... 

Laibinis PE, Whitesides GM, Allara DL, Tao Y-T, Parikh AN, Nuzzo RG (1991) Comparison of the structures and wetting properties of self-assembled monolayers of n-alkanethiols on the coinage metal surfaces, copper, silver, and gold. J Am Chem Soc 113 7152-7167... 

The 5-cent coin of the United States is named after the metal nickel. It is composed of 25% nickel and 75% copper (maybe it should have been named copper, but that name was already used in England for a coin). Thousands of years ago, a variety of metals, mainly gold and silver, were used to make coins. Because of the shortage and price increase of some coinage metals such as gold, silver, and copper, the United States mint now uses less of these metals and substitutes more iron, zinc, nickel, or steel to make the coins of today. 

Gold is relatively inert in comparison to the other two coinage metals of GroupIB copper and silver. It also is chemically more inert than most other metals in the Periodic Table. It does not combine with oxygen, sulfur or selenium even at elevated temperatures. However, it reacts with tellurium in molten state forming gold telluride. 

Of the coinage metals, finely divided copper shows evidence of strong rehybridization of adsorbed ethyne, such as occurs with transition metals Ni, Pd, Pt, and Rh, which have unfilled d orbitals. On the other hand, SER spectra from ethyne on cold-deposited silver at low temperatures show only moderately perturbed 7T-bonded species. There is SERS evidence of polymerization to long-chain polyenes on silver and gold electrodes at room temperature. 

Copper, silver, and gold (group 11) are known as the noble metals or coinage metals because they rarely react. 

This reaction produces activated cobalt metal powder following decomposition of the carbonyl at 200°C in diphenyl ether (DPE). The metal carbonyls are typically very stable at room temperature at elevated temperatures they dimerize and decompose, leaving the zero-valent metal. Photochemical decomposition, or photolysis, is common with coinage metals such as silver and gold. While... 

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