Seizo Misumi

Polarographic Studies of Bis(2,2′,2″-terpyridine) Complexes of Manganese(II), Cobalt(II), Nickel(II) and Europium(III) in Acetonitrile

The reduction mechanism of bis 2,2′,2″-terpyridine complexes of manganese(II), cobalt(II), nickel(II) and europium (III) were investigated in acetonitrile by means of DC and AC polarograph and Kalousek polarograph at DME and cyclic voltammetry at an HDME. It was found that univalent metal complex anions, such as [M-(terpy)2]− (M=manganese and nickel), were formed at the electrode surface in acetonitrile. For the europium(III) complex, the standard rate constant of the second reduction step was estimated.

Circular dichroism of lanthanide (III) complexes [1]—I Some lanthanide (III) complexes of levo-propylenediamine tetraacetic acid

Abstract The absorption and circular dichroism spectra of 1-propylenediaminetetraacetato complexes of Pr(III), Nd(III), Sm(III), Dy(III), Ho(III) and ER(III) were measured in aqueous solutions at room temperature in the range of 600 ∼ 300 mμ. The ligand field splittings of J-levels were much better observed in CD than in absorption spectra. The relative intensity of CD was discussed referring to the intensity of absorption bands, and were well elucidated on the basis that the CD intensity is proportional to the product of magnetic dipole moment and electric dipole moment associated with the electronic transition. Based on this discussion, the result of the present experiments was successfully applied to the determination of the origin of the J-band at ∼380 mμ of Er(III) to which energy level calculations of Wybourne, and Carlson and Crosswhite had given two probable assignments.

A polarographic study of iron(III)-nitrilotriacetic acid complex

Abstract A two-stepped kinetic wave was obtained above pH 4.1 in the reduction of an iron(III)-NTA complex in the presence of excess NTA in acetate buffer solution. The electrode process of the first wave which was controlled by the rate of dissociation of Fe(III)X complex, was reversible and represented a 1-electron change; the formation constant, K FeX , was calculated to be 10 16.01 . The second wave was also kinetic and its electrode process was irreversible and represented a 2-electron change. A relation between the rate constant, g , of the electron transfer reaction, and potential was deduced and it was found that the Fe(II)HX complex would be reduced directly.

The nature of europium ion in carbonate solution and polarographic determination of micro amounts of europium

Abstract The nature of the complex europium carbonate ion in concentrated carbonate solution was studied polarographically. A polarographic method for the determination of micro amounts of europium ion in the presence of diverse ions (and especially lanthanides) was developed.