Rhenium and technetium tricarbonyl complexes of 1,4-Substituted pyridyl-1,2,3-triazole bidentate 'click' ligands conjugated to a targeting RGD peptide.

New 1,4-substituted pyridyl-1,2,3-triazole ligands with pendent phenyl isothiocyanate functional groups linked to the heterocycle through a short methylene or longer polyethylene glycol spacers were prepared and conjugated to a peptide containing the arginine-glycine-aspartic acid peptide motif. Rhenium and technetium carbonyl complexes, [M(CO)(3)L-x(py)](+) (where M=Re-I or Tc-99m(I); L-x=1,4-substituted pyridyl-1,2,3-triazole ligands and py=pyridine) were prepared. One rhenium complex has been characterized by X-ray crystallography, and the luminescent properties of [M(CO)(3)L-x(py)](+) are reported.