Synthesis and characterization of technetiumtetrakis(acetonitrile)bis(triphenylphosphine) cationic complexes

Inorg Chem. 2002 Jul 1;41(13):3337-9. doi: 10.1021/ic020017d.

Abstract

A new route to low-valent technetium complexes containing multiple acetonitrile ligands has been developed. The reduction of TcCl(4)(PPh(3))(2) with zinc metal dust in acetonitrile results in the formation of [Tc(CH(3)CN)(4)(PPh(3))(2)][Zn(2)Cl(6)](1/2). The hexafluorophosphate salt of the analogous Tc(II) cation can be prepared via chemical oxidation of the Tc(I) species, and the Tc(I) cation can be regenerated via chemical reduction. The compounds have been characterized in the solid state via single-crystal X-ray crystallography, and in solution via a combination of spectroscopic techniques and cyclic voltammetry. The structural parameters found in the two complexes are similar to each other; however, the difference in oxidation state is reflected, as expected, in the spectroscopic results. The electrochemical data, obtained from cyclic voltammograms of Tc(CH(3)CN)(4)(PPh(3))(2)](PF(6))(n)() (n = 1,2), mirror the synthetic results in that both compounds possess a reversible redox couple at -0.55 V versus ferrocene, which has been assigned to the Tc(II)/Tc(I) couple.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chemistry, Organic / methods
  • Crystallography, X-Ray
  • Magnetic Resonance Spectroscopy
  • Molecular Conformation
  • Molecular Structure
  • Organotechnetium Compounds / chemical synthesis
  • Organotechnetium Compounds / chemistry*
  • Oxidation-Reduction
  • Phosphines / chemical synthesis
  • Phosphines / chemistry*
  • Radiopharmaceuticals / chemical synthesis
  • Radiopharmaceuticals / chemistry*
  • Spectrometry, Mass, Electrospray Ionization
  • Zinc / chemistry

Substances

  • Organotechnetium Compounds
  • Phosphines
  • Radiopharmaceuticals
  • Zinc