Chemical and Pharmaceutical Bulletin · 1974 · 56 citations · 0 references
Natural SciencesChemistryAnalytical ChemistryInorganic ChemistrySpectroscopyCoordination ChemistryCrystal ChemistryCrystal Field TheoryMetal-ligand BondingRedox ChemistryTransition Metal ComplexesCrystal Field AnalysisCrystal Field ParametersElectronic Structure Of Metal ComplexesInfrared Absorption SpectraInfrared SpectraPotentiometric TitrationTetrahedral ComplexesTetrahedral Coordination
The interaction between ergothioneine and divalent metal ions has been investigated by means of potentiometric titration, visible and near-infrared spectra. The order of the relative formation constants of erogothioneine-metal complexes was Cu (II)>Hg (II)>Zn (II)>Cd (II)>Co (II)≨Ni (II). For ergothioneine-cobalt (II) complex, the crystal field parameter (Dq) and Racah interelectron repulsion parameter (B) calculated were 453 and 971 cm-1, respectively. It was indicated that ergothioneine coordinates to cobalt (II) ion through its sulfur atom and forms a distorted tetrahedral complex.