The equilibrium constants of cadmium(II)-, lead(II)-, magnesium(II)-, and zinc(II)-alpha,beta,gamma,delta-tetrakis(1-methylpyridinium-4-yl)porphine complexes.
The equilibrium constants of alpha,beta,gamma,delta-tetrakis(1-methylpyridinium-4-yl)porphine (TMPyP) complexes of cadmium(II), lead(II), magnesium(II), and zinc(II) were spectrophotometrically determined using the absorption spectra at the Soret band and the fluorescence spectra. The values of the following constants at 25 degrees C and ionic strength 0.1M were evaluated: K(PbP) = 10(-8.07 +/- 0.09), K(CdP) = 10(-7.68 +/- 0.03), K(ZnP) = 10(1.72 +/- 0.08), and K(MgP) = 10(-7.40 +/- 0.08) by the acid hydrolysis reaction of the TMPyP-metal complex at various pHs; K(PbP) = 10(-7.80 +/- 0.04) and K(CdP) = 10(-7.38 +/- 0.04) were determined by the ligand exchange reaction between TMPyP and nitrilotriacetic acid.
Igarashi
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Department of Molecular Chemistry and Engineering, Faculty of Engineering, Tohoku University, Aoba, Aramaki, Sendai 980, Japan.
Suzuki
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Yotsuyanagi
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