Technetium(V) nitrido complexes with tetra-azamacrocycles: monocationic and neutral octahedral complexes containing the [TcN]²⁺core. Crystal structure of [TcN(L¹)H₂O]·2H₂O (H₂L¹= 1,4,8,11-tetra-azacyclotetradecane-5,7-dione)

[Tc(OH2)(CO)3(PPh3)2]+: A Synthon for Tc(I) Complexes and Its Reactions with Neutral Ligands

“…As in the other few complexes containing the mer -{Tc­(CO) 3 } + motif, ,− the bonds between Tc and the two carbonyl ligands in the trans -position to each other are weakened compared to the third CO ligand, which has another ligand (here water) in the trans -position. The Tc–O­(water) bond lengths are similar to those in other Tc complexes containing aqua ligands. − One of the few structural differences between the three solid-state structures are the C1–Tc–O10 and C3–Tc–O10 angles. They are significantly smaller (83.9(1)°, 86.9(1)) in the BArF 24 – salt than in the two hydrogen-bridged dimers (90.34(7)° to 93.20(8)°), in which the two carbonyl ligands are slightly bent away from the H-bonded anions.…”

“…Despite the importance of the technetium chemistry in aqueous media, there are surprisingly few structural reports about Tc complexes with aqua ligands. Of course, there are a number of oxido and nitrido complexes, where water sometimes appears as a strongly labilized ligand trans to O 2– and N 3– ; − but this is the most labile coordination position in such molecules, and the replacement of such aqua ligands does not represent a synthetic approach to stable ligand exchange products. In addition to some instable chlorido complexes of technetium­(V) and -(IV), − there exist to the best of our knowledge hitherto only three compounds, in which aqua ligands have been proven by X-ray structural analysis (Chart ).…”

99mTc-Labeled Small Peptides as Diagnostic Radiopharmaceuticals

“…The nitrido ligand is a powerful π-electron donor and shows a high capacity to stabilize the Tc(V) oxidation state. The [Tc⋮N] 2+ core forms technetium(V) nitrido complexes with a variety of chelators. − The technetium(V) nitrido complex, [ 99m TcN(noet) 2 ] (noet = N -ethyl- N -ethoxydithiocarbamato), has been developed as a new myocardial imaging agent by CIS−Bio International . However, very little effort has been made to use the [Tc⋮N] 2+ core for the 99m Tc-labeling of biomolecules.…”

Synthesis of a Novel Class of Trigonal Bipyramidal Nitrido Tc(V) Complexes with Phosphino−Thiol Ligands. Crystal Structure of [99gTc(N)(L1)2] [L1 = 2-(Diphenylphosphino)ethanethiolato] and [99gTc(N)(L5)2] [L5 = 2-(Ditolylphosphino)propanethiolato]

“…Some years ago, Baldas and co-workers first explored nitrido technetium chemistry. − Following these pioneering investigations, our research group and others have further studied the coordination chemistry and biological properties of technetium complexes characterized by the presence of the terminal Tc⋮N multiple bond. − Extensive studies have been carried out on the synthesis and biological evaluation of square pyramidal nitrido technetium(V) complexes with dithiocarbamate, , dithiocarboxylate, , and dithiophosphinate ligands, and with ONS-type Schiff base ligands. , Five- and six-coordinated nitrido technetium(V) complexes have been also prepared with N 2 S 2 -type ligands, , diphosphines, and polyphosphines, , and cyclic and acyclic polydentate amine ligands. − …”