The mechanism of interaction between molybdogermanic acid and the basic dye Crystal Violet.
On the basis of light-absorption studies on solutions of Crystal Violet (CV) molybdogermanate in acetone, the optimal pH conditions for quantitative formation of molybdogermanic acid (MGA) have been determined. Di, tri-, and tetra-salts of MGA have been formed and isolated. It has been shown that formation of the higher salts is favoured by lowering the acidity, but this increases also the amount of the solid co-product CV-isopolymolybdate. To overcome this inconvenience the surplus molybdate ions are masked by adding oxalate ions, thus allowing the separation of the corresponding solid tetra-salt up to pH = 6.5; the molar absorptivity of this compound in acetone solution is very high (4.2 x 10(5) 1.mole(-1).cm(-1)).
Mirzoyan
F V
FV
Institute of Inorganic and General Chemistry, Armenian Academy of Sciences, Yerevan, Yerevan State University, USSR.
Tarayan
V M
VM
Hairiyan
E K
EK
Grigorian
N A
NA