Electroplating coordination compounds

Electroplating. Aluminum can be electroplated by the electrolytic reduction of cryoHte, which is trisodium aluminum hexafluoride [13775-53-6] Na AlE, containing alumina. Brass (see COPPERALLOYS) can be electroplated from aqueous cyanide solutions which contain cyano complexes of zinc(II) and copper(I). The soft CN stabilizes the copper as copper(I) and the two cyano complexes have comparable potentials. Without CN the potentials of aqueous zinc(II) and copper(I), as weU as those of zinc(II) and copper(II), are over one volt apart thus only the copper plates out. Careful control of concentration and pH also enables brass to be deposited from solutions of citrate and tartrate. The noble metals are often plated from solutions in which coordination compounds help provide fine, even deposits (see Electroplating). 

Electrophotography, 6,122 Electroplating addition reagents, 6, 5 coordination compounds, 6,4 Electroreduction plutonium(IV)... 

The two areas specified will require the coverage of a wide range of chemistry. Although the basic principles of electroplating are well understood, and the role of coordination compounds in some plating baths well established, new work and new directions are discernible, particularly in relation to bath additives and their mode of action. 

The heterocyclic character of caramels from ammonia and amino acid processes may suggest that such caramels may be quatemized by metal ions to form metal coordination compounds. Indeed, such complexes with Cu, Cd " ", Ni " ", and Zn have been found, and studied by Agarwal and co-workers. Because caramel may be a transporter of ions in solution, it has been the subject of a study of its surface activity and its usefulness as a brightener in electroplating baths. ... 

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