Induced fac–mer rearrangements in {M(CO)₃}⁺ complexes (M = Re, ^99(m)Tc) by a PNP ligand

Abstract

The fac–mer rearrangements in [MX3(CO)3]2– (M = Re, 99Tc) induced by a pincer-type ligand (PNP) and a “halide scavenger” is reported. The reactions of fac-[99mTc(CO)3(OH2)3]+ or [99mTcO4]– in saline both...

[Tc(NO)(Cp)(PPh3)Cl] and [Tc(NO)(Cp)(PPh3)(NCCH3)](PF6), and Their Reactions with Pyridine and Chalcogen Donors

“…It confirms the presence of PO2F2 − (with a signal at −81.1 ppm) and HF (with a signal at −137.9 ppm) amongst other degradation products of hexafluorophosphate in such solutions. In a very recent paper, there are also the first reports of the coordination of PO2F2 − ligands originating from the undesired hydrolysis of PF6 − anions in Tc(I) complexes [49]. The problems with the synthesis of [Tc(NO)(Cp)(PPh 3 )(NCCH 3 )](PF 6 ) in high yields and purity can be avoided by a complete exclusion of water or the use of more robust counter ions.…”

“…It confirms the presence of PO2F2 − (with a signal at −81.1 ppm) and HF (with a signal at −137.9 ppm) amongst other degradation products of hexafluorophosphate in such solutions. In a very recent paper, there are also the first reports of the coordination of PO2F2 − ligands originating from the undesired hydrolysis of PF6 − anions in Tc(I) complexes [49]. in the formation of the targeted ligand-exchange products, even in cases where the corresponding rhenium analogs are well known [94][95][96].…”

“…This is mainly attributed to variations in their redox potentials [45,46]. More recently, such differences have also become evident for low-valent technetium and rhenium complexes and for corresponding organometallic compounds [47][48][49][50]. In addition to such basic considerations, novel technetium compounds are always interesting as potential tracers for diagnostic nuclear medicine.…”