Re(V) complexes containing the phenylimido (NPh2−) core and SNS-thiosemicarbazide ligands

Phenylimido complexes of rhenium: fluorine substituents provide protection, reactivity, and solubility

“…The Re–N bonds are clearly in the range of double bonds and the slightly bent phenylimido units (Re–N–C angles between 164 and 173°) are a common feature of such compounds. 22–45 The replacement of one of the PPh 3 ligands of [Re(NPhF)Cl 3 (PPh 3 ) 2 ] goes along with a rearrangement of the coordination sphere of rhenium. The incoming isocyanides are found in cis position to phosphine in all 1 : 1 complexes.…”

“…The corresponding bromido complex [Re(NPh)Br 3 (PPh 3 ) 2 ] is slightly more soluble and is, thus, occasionally used as a better suitable starting material. 37,40,44,45 Alternatively, substitutions on the arylimido ligand with the carboxylic, hydroxylic or amine group provide an enhanced solubility. [46][47][48][49][50] Such residues, however, sometimes undergo undesired reactions with co-ligands and/or solvents (e.g.…”

“…Unfortunately, the rhenium compound is significantly less soluble than its technetium analog. Thus, predominately reactions with strong chelators or with robust ligands, 22–45 which resist harsh reaction conditions, give pure products in good yields. The corresponding bromido complex [Re(NPh)Br 3 (PPh 3 ) 2 ] is slightly more soluble and is, thus, occasionally used as a better suitable starting material.…”

Bifunctional chelators for radiorhenium: past, present and future outlook

“…112 More recently, various novel Re(V) complexes have been synthesised following the "mixed ligand" strategy with the intent of synthesising their radiorhenium congeners for radiotherapy, although very few of these radioactive compounds have come to fruition. 113,114 While the [ReN] 2+ core is stable and very versatile, novel radiorhenium therapeutic agents of this type has not found widespread use, likely due to the many steps required in the labelling process of these compounds.…”

Reactivity of [ReOCl3(PPh3)2] Towards Substituted Anilines

“…In recent years, there has been an increased interest in the development of the chemistry of high-valent rhenium oxo [1][2][3][4][5][6] and imido [7][8][9] complexes, as rhenium is still a highly relevant nonradioactive surrogate for γ-emitting 99m Tc, the most commonly used isotope in diagnostic nuclear medicine. [10] Recently, rhenium compounds containing β-emitting 186 Re (E max = 1.07 MeV; t 1/2 = 90 h) and 188 Re (E max = 2.12 MeV; t 1/2 = 17 h) isotopes showed potential for their use in therapeutic nuclear medicine as radiopharmaceuticals, since both radioisotopes have suitable properties for cancer therapy.…”