Metatungstates isomers

The formation of o -mctatungslate in a more acid medium is not direct either. It seems to take place after rapid formation of para A, which then transforms itself into an unknown species, the P-nietatungstate. This compound would in turn form the / -metatungstate isomer that would slowly transform into the stable a-metatungstate. The a and ft isomers differ by a 120° rotation of one tritungstic group around the axis (Figure 4.24),... 

The initially formed product in tungstate solutions acidified to H+/W04 = 1.5 is so-called pseudometatungstate anion (%p) which has to date been isolated in noncrystalline form only, but which has a characteristic polarogram. Solutions of ip are slowly converted successively to j8 and a isomers of the metatungstate anion [(tyW O ]6-. At 80 °C and pH 3 the half-lives of both processes are 70 min.48... 

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