Gold-Copper Compounds

Figure4.11 Comparison of experimental dissociation energies of gold intermetallic compounds with those of copper and silver from mass spectroscopic measurements by Cingerich and coworkers [18, 159, 173, 176] arranged in group order according to the periodic table.

Alloys with Copper compounds Silver compounds Gold compounds... 

In the periodic table of the elements, copper is listed in group 11, together with silver and gold. Copper, as a late transition element, occurs in a range of oxidation states (Cu(0), Cu(I), Cu(II), Cu(III), and Cu(IV)), and the ions readily form complexes yielding a variety of coordination compounds. Oxidation states I, II, and III... 

In interstitial compounds, however, the nonmetal is conveniently regarded as neutral atoms inserted into the interstices of the expanded lattice of the elemental metal. Obviously, this is an oversimplification, as the electrons of the nonmetal atoms must interact with the modified valence and conduction bands of the metal host, but this crude picture is adequate for our purposes. On this basis, Hagg made the empirical observation that insertion is possible when the atomic radius of the nonmetal is not greater than 0.59 times the atomic radius of the host metal—there is no simple geometrical justification for this, however, as the metal lattice is concomitantly expanded by an unknown amount. These interstitial compounds are sometimes called Hagg compounds.9,10 They are, in effect, interstitial solid solutions of the nonmetal in the metal (as distinct from substitutional solid solutions, in which actual lattice atoms are replaced, as in the case of gold-copper and other alloys Section 4.3). 

The modes of action of these drugs are still uncertain, but it seems likely that there are antiinflammatory and antienzyme activities of gold(I) compounds. It may be that the drugs modulate the body s immune response in some way. Unlike iron and copper, which are essential elements, gold does not have a well-defined transport, storage or enzyme function.17... 

A very large number of copper compounds have been tested for antiinflammatory activity, and various copper complexes of antiarthritic drugs have been found to be more effective than the parent drugs alone (including aspirin, D-penicillamine, ketoprofen and gold thiomalate).25... 

---