Synthesis, Characterization and Crystal Structure of {N-(2-Mercaptoacetyl)-N′-[4-(pentene-3-one-2)]ethane-1,2-diaminato } oxotechnetium(V)

{ N-(2-Mercaptoacetyl)-N′-[4-(pentene-3-one-2)]ethane-1,2-diaminato} oxotechnetium(V) has been prepared by the reaction of (Bu₄N)TcOX₄ complexes (X = Cl, Br) with N-(mercaptoacetyl)-N′-[4-(pentene-3-one-2)]ethane-1,2-diamine in methanolic solution. The compound forms dark red crystals which were characterized by elemental analysis, IR and ¹H NMR spectroscopy, mass spectrometry, as well as an X-ray structure determination. The compound crystallizes triclinic in the centrosymmetric space group PĪ with a = 776.50(3), b = 819.69(6), c = 1040.43(7) pm, α = 92.944(6)°, β = 110.805(5)° and γ = 109.957(5)°. The final R value is 0.023. In the monomeric complex the five coordinate technetium atom exhibits a square pyramidal environment with the donors of the tetradentate ligand in the basal plane and the oxo ligand in the apical position. The bond length Tc–O = 165.7(2) is within the normal range of Tc=O double bonds.