Yoichi Shimura

Rotatory Dispersion of Metallic Co-ordination Compounds. II. Absorption Spectra and Rotatory Dispersion of Cobalt(III) Complexes of EDTA

The rotatory dispersion measurements have been made for D-Na2[Co(edta)NO2]·3H2O, D-K[Co(edta)]·3H2O, D-K2[Co(edta)Cl]·3H2O and D-cis-[Co en2(NO2)2] I. On the basis of these measurements, the relation of the splitting of the first absorption band with the so-called anomalous rotatory dispersion has been discussed. In the anomalous rotatory dispersion of D-[Co(edta)NO2]2−, there appear two inver-sive dispersions due to the component absorption, Ia and Ib, of the split first absorption band. Similarly considered, it has been shown that the first absorption band of [Co(edta)]− or [Co(edta)Cl]2− may have two component absorptions in accordance with the behavior of its rotatory dispersion curve.

Absorption Spectra of Bis(sulfito) and Bis(thiosulfato) Complexes of Cobalt(III)

It has been shown that the near ultraviolet “specific band” of a trans isomer of bis(sulfito) or bis(thiosulfato) cobalt(III) complexes is more bathochromic than the corresponding cis isomer. The cis-[Co(SO3)2(en)2]− complex was optically resolved and its circular dichroism spectrum reported.