Rhenium diazenide ternary complexes with dithiocarbamate ligands: towards new rhenium radiopharmaceuticals

Dalton Trans. 2007 Jan 7:(1):73-82. doi: 10.1039/b611403b. Epub 2006 Oct 31.

Abstract

The reaction of the mono-diazenide core, [ReCl2(NNC6H(4)-4-OCH3)(NCCH3)(PPh3)2], with four equivalents of the sodium or potassium salts of dithiocarbamate (dtc) ligands gives neutral complexes of the formula [Re(NNC6H(4)-4-OCH3)(dtc)2(PPh3)]. It is possible to use a wide range of dithiocarbamate ligands (S2CNRR') with a variety of R groups (R=R'=methyl, phenyl or ethyl; R=methyl, R'=phenyl and R=R'=morpholino). Substitution reactions with dtc ligands on the mono-diazenide derived from 2-hydrazinopyridine, [ReCl2(NNC5H4N)(PPh3)2, give the analogous complexes, [Re(NNC6H5N)(dtc)2(PPh3)]. The new complexes have been characterised by a combination of NMR spectroscopy, mass spectrometry and X-ray crystallography. Cyclic voltammetry measurements in dimethyl formamide show that the rhenium diazenido-dtc complexes undergo a quasi-reversible oxidation tentatively assigned to a ReIII/ReIV oxidation. Since the parent complex, [ReCl2(NNC6H(4)-4-R)(NCCH3)(PPh3)2] can be prepared directly from perrhenate and readily derivatised with dtc ligands these complexes have potential relevance to the development of new therapeutic rhenium radiopharmaceuticals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Hydrazines / chemistry*
  • Ligands
  • Magnetic Resonance Spectroscopy / methods
  • Models, Molecular
  • Molecular Conformation
  • Organomercury Compounds / chemical synthesis
  • Organomercury Compounds / chemistry*
  • Radiopharmaceuticals / chemical synthesis*
  • Radiopharmaceuticals / chemistry
  • Rhenium / chemistry*
  • Sensitivity and Specificity
  • Stereoisomerism
  • Thiocarbamates / chemistry*

Substances

  • Hydrazines
  • Ligands
  • Organomercury Compounds
  • Radiopharmaceuticals
  • Thiocarbamates
  • Rhenium