Oxyanion complexes

In this paper we deal with complexes in which the donor atom is exclusively oxide(—II). Such complexes include aquo complexes, which are well documented, and oxyanion complexes such as phosphato, borato, etc. which are present in vitreous phosphates, borates, etc. and in anhydrous oxyacids. We therefore are dealing with complexes, of metal ions M , comprising a system which can be written schematically as... 

Table 44 Rates of Aquation and Alkaline Hydrolysis of Some Cobalt(IIT)-Oxyanion Complexes...

In Table VI the results of this treatment are listed. Unfortunately, charge transfer data are not available for the complexes (fluoride and acetate) of interest. However, as a qualitative estimate of the manner in which AHcov varies across the lanthanide series with change in the nature of the anion, we have plotted on relative scales the values in flnal column of Table VI and the differences in the enthalpies for the fluoride and acetate complexes (Figure 4). The similarity of the curves provides some evidence that the variation in enthalpy for the fluoride complexes compared with the oxyanion complexes is possibly attributed to a decrease in the covalent contribution as a result of the smaller nephelauxetic effect of fluoride compared to oxygen. 

Table 70 Preparations Some O-bonded Oxyanion Complexes Containing S, Sc, Te, As and Re... 

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