Compounds of Copper, Silver and Gold

Formation of Metal—Oxygen Surface Compounds on Copper, Silver, and Gold Electrodes... 

For example, the results in Table 3 suggest that binary carbonyls of copper, silver and gold which have been detected spectrometrically in matrices at very low temperatures27, contain metal-CO bonds which are approximately of the same strength as those in Mn2(CO)i0. Similar considerations apply to carbonyls of palladium and platinum which have also been detected by matrix isolation spectrometry28. All of these binary compounds are unstable with respect to [M(c) + CO(g)J at room temperature. 

Write the electron configurations and the sizes of the atoms of the copper subgroup elements. What oxidation states do these elements exhibit in their compounds Give examples. What position do they occupy in the electrochemical series Write the equations of the reactions of copper, silver, and gold with acids. Give a comparative general characteristic of the physical and chemical properties of the elements of Group one. 

Coinage metals Historically, copper, silver, and gold were logical choices for use in coins. These metals are not abimdant in Earth s crust and are considered rare. Most elements occur combined in compounds, but copper, silver, and gold occur nearly pure in rocks fairly close to Earth s surface, making them easy to mine. People revere them because of their beauty and rarity. Finally, their properties allow them to be easily shaped, stamped, and marked for value. 

The chemistry of transition metals, lanthanides and actinides is significantly influenced by relativistic effects. Qualitatively, these effects become apparent in the comparison of certain structural properties or reactivity patterns for a group of metals, for example, trends in the chemistry of copper, silver and gold. Quantification of relativistic effects can, however, only be achieved by relating the experimental findings to the results of adequate ab initio studies. Reference to theory is required because nonrelativistic properties cannot be probed directly. Thus, elements behave relativis-tically in any kind of experiment, whether one deals with the spectrum of Hj or the properties of transuranium compounds. 

In fact, the classification of chemical elements is valuable only in so far as it illustrates chemical behaviour, and it is conventional to use the term transition elements in a mote restricted sense. The elements in the irmer transition series from cerium (58) to lutetium (71) are called the lanthanoids those in the series from thorium (90) to lawrencium (103) are the actl-noids. These two series together make up the /block in the periodic table. It is also common to include scandium, yttrium, and lanthanum with the lanthanoids (because of chemical similarity) and to include actinium with the actinoids. Of the remaining transition elements, it is usual to speak of three main transition series from titanium to copper from zirconium to silver and from hafnium to gold. All these elements have similar chemical properties that result from the presence of unfilled d-orbltals in the element or (in the case of copper, silver, and gold) in the ions. The elements from 104 to 109 and the undiscovered elements 110 and 111 make up a fourth transition series. The elements zinc, cadmium, and mercury have filled d-orbltals both in the elements and in compounds, and are usually regarded as nontransition elements forming group 12 of the periodic table. 

SSIE of Copper, Silver and Gold Compounds with Zeolites... 

Univalent halides—e.g. NH l.AgCl CsCl.CuCl 2KCl.CuCl etc. The halides of the alkali metals do not often unite together to form stable complexes. Univalent copper, silver, and gold form double chlorides with the alkali halides, while the corresponding double bromides of silver and gold and the double iodide of silver have not been made. The facts can be summarized in the form of a scheme due to P. Pfeiffer (1902), where the hyphens represent compounds which have not yet been prepared ... 

Copper, silver, and gold in Group I show a similarity to sodium and potassium principally in the fact that they form certain compounds of the same type, for example, M20 and MCI. Zinc, cadmium, and mercury in Group II resemble calcium, barium, and strontium in that they form compounds of the types MO, MSO4, MC12, etc. In other respects, the divergence in the properties of the elements of the A and B Families is at a maximum in these two groups. 

The chemical resources of early humans were limited to the metals and compounds on the earth s surface. A few metals (e.g., copper, silver, and gold) were found uncombined (native) in nature, so they have been available for many centuries. It is believed that the iron first used may have been found as uncombined iron that had reached the earth in the form of meteorites. In contrast, elements such as fluorine and sodium are produced by electrochemical reactions, and they have been available a much shorter time. 

Copper, Silver and Gold Phosphides.—The copper phosphides are crystalline compounds of metallic appearance and properties which are usually prepared by direct union of the elements.8 Phosphorus begins to combine with copper at about 400° C., and at 700° C. the copper was found to take up 20 per cent.,9 some of which was expelled at higher temperatures. Slightly above the melting-point of the phosphide 14 per cent, was retained, which corresponds to tri-cuprous phosphide, Cu3P.9 The velocity of the combination increases between 600° and 700° C.10 At ordinary pressures 15 per cent, of phosphorus is the limit of the amount which will remain dissolved in the fused mixture, and some of this is present as red phosphorus.11... 

Like copper, silver and gold have a single s electron outside the completed d shell, but in spite of the similarity in electronic structures and ionization potential, the chemistries of Ag, Au, and Cu differ more than might be expected. There are no simple explanations for many of the differences although some of the differences between Ag and Au may be traced to relativistic effects on the 6s electrons of the latter. The covalent radii of the triad follow the trend Cu < Ag Au, i.e., gold has about the same or a slightly smaller covalent radius than silver in comparable compounds, a phenomenon frequently referred to as relativistic contraction (c/. lanthanide contraction). 

Tossell, J. A., and D. J. Vaughan (1981). Relationships between valence orbital binding energies and crystal structures in compounds of copper, silver, gold, zinc, cadmium and mercury. Inorg. Chem. 20, 3333-40. 

The three metals copper, silver, and gold comprise group Ib of the periodic table. These metals all form compounds representing oxidation state +1, as do the alkali metals, but aside from this they show very little similarity in properties to the alkali metals. The alkali metajs are ery soft and light, and very reactive chemically, whereas the metals of ihe copper group are much harder and heavier and are ratlier inert, sufficiently so to occur in the free state in nature and to be easily obtainable by reducing their compounds, sometimes simply by heating. 

The three elements lithium, sodium, and potassium bear little resemblance to copper, silver, and gold in their inorganic derivatives but, with the exception of gold, they show more resemblance in their organo-metallic compounds. 

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