Rhenium(I) and technetium-99m(I) fac-tricarbonyl complexes with 4-(imidazolin-2-yl)-3-thiabutanoic acid derivatives as tridentate ligands: Synthesis and structural characterization

Two rhenium(l) tricarbonyl complexes, with the monoanionic tridentate NSO type ligand, 4-(imidazolin-2-yl)-3-thiabutanoic acid and 4-(N-ethylimidazolin-2-yl)-3-thiabutanoic acid were synthesized and isolated in pure form. Both complexes were characterized by spectroscopic methods and elemental analysis. The solid-state structure of 4-(imidazolin-2-yl)-3-thiabutanoic acid and of both complexes was established by X-ray crystallography. The geometry about the rhenium is octahedral. The analogous technetium-99m complexes were also prepared quantitatively by the reaction of both ligands with the fac-[(99m)Tc(CO)(3)(H(2)O)(3)](+) synthon and their identity was established by chromatographic comparison to their rhenium congeners. (C) 2009 Elsevier Ltd. All rights reserved.