trans-Bisaquabis[1,2-bis(diphenylphosphino)ethane]technetium(I) tetraphenylborate

[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.…”

“…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 ). This involves the Tc­(III) cation [TcCl 2 ­(OH 2 )­(tacn)] + (tacn = 1,3,6-triazacyclononane), a cationic Tc­(I) complex with DPPE (DPPE = 1,2-bis­(diphenylphosphino)­ethane), and a neutral tricarbonyltechnetium­(I) complex . Particularly the latter compound seems to be interesting for nuclear medical considerations, since it belongs to the family of tricarbonyltechnetium­(I) complexes, that originates from the (structurally not yet fully characterized) [Tc­(CO) 3 ­(OH 2 ) 3 ] + cation .…”

The Chemistry of Technetium–Water Complexes within the Manganese Triad: Challenges and Perspectives

“…Y stands for H 2 O or halide ligands, X = N or S. [36] Besides the complexes discussed above, technetium compounds containing H 2 + trans to the terminal oxido ligand but are of no relevance for substitution reactions. [32] The oxido ligand exerts a strong trans influence and so substitution of water did not induce a labelling opportunity since any ligand in this position is too weakly bound. The structural motif [NϵTc-OH 2 ] 2+ was also found in many complexes but, again, the position trans to the nitrido group is too unstable to be useful for irreversible labelling.…”