Spektrophotometrische Bestimmung der Zusammensetzung und der Stabilitätskonstante des Komplexes von Strontium mit Magon

Sr²⁺ has been found to form with “Magon”[sodium 1-azo-2-hydroxy-3-(2.4-dimethylcarboxanilido)-naphthalene-1′-(2-hydroxybenzene-5-sulphonate)] in 15% ethanol in the pH range 12–13 a stable red complex (λ=495) in the ratio Sr²⁺∶H₂R=1∶2. At optimum pH the absorption maximum is attained in 20 minutes and the complex is stable for 3 hours. The composition of the complex was found by the method of isomolar series. A regression equation has been deduced by the procedure ofKomar ⁶ andTolmatchev ⁷, and the values of the molar extinction coefficient of absorption and stability constant of the complex determined.