Russian Chemical Bulletin

, Volume 45, Issue 7, pp 1734–1739 | Cite as

Influence of the redox state of the ligand on the dealkylation of substituted methylcobaloximes in the presence of heavy metal ions

  • E. R. Milaeva
  • A. V. Androsova
  • O. V. Polyakova
  • A. I. Prokof'ev
  • V. S. Petrosyan
Organometallic Chemistry


The synthesis of cobaloxime and methylcobaloxime containing sterically hindered 2,6-di-tert-butylphenol fragments in the ligand is described. Spectral studies of the demethylation of methylbis(dimethylglyoximato)cobalt (1a), methylbis(diphenylglyoximato)cobalt (1b), methylbis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)glyoximato]cobalt (1c) pyridinates were carried out in the presence of Cd2+, Hg2+, Sn4+, Pb2+, and Pb4+ ions, The free radical forms of the complexes containing a phenoxy radical W the ligand are formed during oxidation. The ESR spectra are given. The unpaired electron in the periphery of the methylcobaloxime ligand1c interacts with the Co-CH3 fragment through the conjugated systems, enhancing the donating properties of the equatorial ligand of the complex, which leads to the rapid cleavage of the Co-C bond. Therefore the demethylation of methylcobaloxime in the presence of heavy metal ions occurs in a significantly shorter time.

Key words

cobaloxime methylcobaloxime heavy metals sterically hindered phenol free radical ligand demethylation 


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Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • E. R. Milaeva
    • 1
  • A. V. Androsova
    • 1
  • O. V. Polyakova
    • 1
  • A. I. Prokof'ev
    • 2
  • V. S. Petrosyan
    • 1
  1. 1.Department of ChemistryM. V. Lomonosov Moscow State UniversityMoscowRussian Federation
  2. 2.A. N. Nesmeyanov Institute of Organoelement CompoundsRussian Academy of SciencesMoscowRussian Federation

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