Kinetics of decarbonylation of pentacarbonyltechnetium halides in solution

Complexes of technetium(I) (99Tc, 99mTc) pentacarbonyl core with π-acceptor ligands (tert-butyl isocyanide and triphenylphosphine): Crystal structures of [Tc(CO)5(PPh3)]OTf and [Tc(CO)5(CNC(CH3)3)]ClO4

“…The mixture was stirred overnight, and crystalline [Tc(CO) 5 PPh 3 ]OTf was precipitated by adding diethyl ether. The IR spectrum of the complex in CH 2 Cl 2 contained a strong CO band at 2057.9 cm À1 , assignable to the pentacarbonyl group [22]. The 99 Tc NMR spectrum of [Tc(CO) 5 PPh 3 ]OTf in CH 2 Cl 2 contained a doublet at d = 1958 ppm with J TcP = 364 Hz (Fig.…”

“…The second one is simpler from the synthetic viewpoint, but it may be difficult to find ligand combinations that would form a single complex species with [Tc(CO) 3 ] + on the tracer level. It seems very promising to use precursors containing [Tc(CO) 4 ] + or even [Tc(CO) 5 ] + cores, to label a biomolecule via bidentate or monodentate ligands, respectively.…”

“…For example [ 99 TcCl(CO) 5 ] completely decomposes in a noncoordinating (e.g., CCl 4 ) solvent at room temperature into dimeric tetracarbonyl chloride within a day and polymerizes on heating in the solid state to form tetrameric tricarbonyl chloride [4]. In coordinating solvents (e.g., acetonitrile, THF) the decarbonylation is slightly faster [5].…”

Reaction of technetium hexacarbonyl cation with acetonitrile: Kinetics, product structure, DFT calculations

“…[4]. Pentacarbonyltechnetium iodide [TcI(CO) 5 ] (0.001 mol) was dissolved in CH 2 Cl 2 , and solid AgClO 4 (0.002 mol) was added.…”

“…The content of the [Tc(CO) 6 ] þ cation (in the mixture of technetium carbonyl species) relative to the initial tricarbonyltriaqua complex was low, and no solid salt of this cation was isolated. Keeping in mind the biological study of the complex, we developed a procedure for preparing [Tc(CO) 6 ] þ cation in an aqueous solution in a high yield [3,4]. Using this procedure, we also prepared 99m Tc hexacarbonyl in a reasonable yield.…”