Thallium complex formation equilibria

Recently, the formation, structure, equilibrium, and kinetics of a family of cyano compounds containing a direct and not supported by ligands platinum-thallium metal-metal bond have been reported. The complexes are synthesized according to the reaction ... 

A similar model for the case of thallium cuprate is complicated by the large number of parameters that affect the state of the system, and also by the necessity to introduce two experimentally unknown quantities simultaneously into the model. However, taking into account the character of the pH dependences of all the processes that occur with the participation of thallium and copper, one can suppose that the shape of the thallium cuprate stability region would be close to that for the mixed oxide. That is, its width would increase with increasing concentration of copper ions (hydroxo complexes) within the crystallization zone. Although the crystallization process took place under a fortiori non equilibrium conditions, the results of the preparative analysis agree qualitatively with the concept of stability of the products. The interval over which formation of thallium cuprate on copper substrates occurs and the formation of the mixed oxide on platinum and carbon substrates can be observed is wider for higher values of the pH [352-354]. 

Singh, S.S. and Brydon, J.E. (1969) Solubility of basic aluminium sulfates at equilibrium in solution and in the presence of montmorillonite. Soil ScL, 107, 12—16. Sipos, P., Capewell, S.G., May, P.M., Hefter, G.T, Laurenczy, G., Lukacs, F., and Roulet, R. (1997) tI-NMR and UV-Vis spectroscopic determination of the formation constants of aqueous thallium(l) hydroxo-complexes. J. Solution Chem., 26, 419-431. Srinivasan, K. and Rechnitz, G.A. (1968) Reaction rate measurements with fluoride ion-selective membrane electrode. Formation kinetics of ferrous fluoride and aluminium fluoride complexes. Anal. Chem., 40, 1818-1825. 

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