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Rhenium and technetium tricarbonyl complexes of N-heterocyclic carbene ligands.
Chan, Chung Ying; Pellegrini, Paul A; Greguric, Ivan; Barnard, Peter J.
Afiliación
  • Chan CY; Department of Chemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia.
Inorg Chem ; 53(20): 10862-73, 2014 Oct 20.
Article en En | MEDLINE | ID: mdl-25280253
ABSTRACT
A strategy for the conjugation of N-heterocyclic carbene (NHC) ligands to biomolecules via amide bond formation is described. Both 1-(2-pyridyl)imidazolium or 1-(2-pyridyl)benzimidazolium salts functionalized with a pendant carboxylic acid group were prepared and coupled to glycine benzyl ester using 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide. A series of 10 rhenium(I) tricarbonyl complexes of the form [ReX(CO)3(CN)] (CN is a bidentate NHC ligand, and X is a monodentate anionic ligand Cl(-), RCO2(-)) were synthesized via a Ag2O transmetalation protocol from the Re(I) precursor compound Re(CO)5Cl. The synthesized azolium salts and Re(I) complexes were characterized by elemental analysis and by (1)H and (13)C NMR spectroscopy, and the molecular structures for one imidazolium salt and seven Re(I) complexes were determined by single-crystal X-ray diffraction. (1)H NMR and mass spectrometry studies for an acetonitrile-d3 solution of [ReCl(CO)3(1-(2-pyridyl)-3-methylimidazolylidene)] show that the monodentate chloride ligand is labile and exchanges with this solvent yielding a cationic acetonitrile adduct. For the first time the labeling of an NHC ligand with technetium-99m is reported. Rapid Tc-99m labeling was achieved by heating the imidazolium salt 1-(2-pyridyl)-3-methylimidazolium iodide and Ag2O in methanol, followed by the addition of fac-[(99m)Tc(OH2)3(CO)3](+). To confirm the structure of the (99m)Tc-labeled complex, the equivalent (99)Tc complex was prepared, and mass spectrometric studies showed that the formed Tc complexes are of the form [(99m/99)Tc(CH3CN)(CO)3(1-(2-pyridyl)-3-methylimidazolylidene)](+) with an acetonitrile molecule coordinated to the metal center.
Asunto(s)

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Compuestos Organometálicos / Renio / Monóxido de Carbono / Tecnecio / Compuestos Heterocíclicos / Metano Idioma: En Año: 2014 Tipo del documento: Article

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Compuestos Organometálicos / Renio / Monóxido de Carbono / Tecnecio / Compuestos Heterocíclicos / Metano Idioma: En Año: 2014 Tipo del documento: Article