The reaction of [ReOCl3(PPh3)2] with an equivalent amount of 4‐fluoroaniline gives the rhenium(V) complex [Re(NPhF)(NH2PhF)Cl3(PPh3)] as the major product, whereas from a reaction with an excess of the aniline the dinuclear compound [{Re(NPhF)(NH2PhF)Cl2(PPh3)}2O] was isolated. The addition of an excess of PPh3 to the [ReOCl3(PPh3)2]/4‐fluoroaniline reaction mixture gives [Re(NPhF)Cl3(PPh3)2] in good yields. The products were studied by NMR spectroscopy and X‐ray diffraction.

A series of technetium complexes with (η5-cyclopentadienyl)­tris­(dimethyl phosphito-P)­cobaltate­(III), also known as the “Kläui ligand” {LOMe}−, has been prepared. The products span seven different oxidation states (+1 to +7) of the radioactive transition metal and comprise nitrosyl, halide, oxido and nitrido complexes. All members of this series ([TcI(NO)­Cl­(PPh3)­(LOMe)], [TcII(NO)­Cl2(LOMe)], [TcIIICl2(PPh3)­(LOMe)], [TcIVCl3(LOMe)], [TcVOCl2(LOMe)], [TcVNCl­(PPh3)­(LOMe)], [TcVINCl2(LOMe)], and [TcVIIO3(LOMe)] are air- and water-stable compounds, which recommends this class of technetium complexes as potential candidates for nuclear medical imaging procedures.

Reactions of [Tc(NO)Cl(Cp)(PPh 3 )] with a series of monodentate ligands X − (X − = I − , I 3 − , F 3 CSO 3 − , CF 3 COO − , or SCN − ) result in a ready replacement of the chlorido ligand and the formation of complexes of the general composition [Tc(NO)X(Cp)(PPh 3 )]. Technetium retains its oxidation state "+1" and its pseudotetrahedral coordination environment. [Tc(NO)(SCN)(Cp)(PPh 3 )] is the first technetium complex with an S-coordinated SCN − ligand. The complexes are stable as solids. In solution, however, a slow isomerization of the thiocyanato compound into the thermodynamically more stable isothiocyanato species is observed, while solutions of [Tc(NO)(I 3 )(Cp)(PPh 3 )] undergo an internal oxidation under formation of the technetium(II) complex [Tc(NO)(I) 2 (Cp)]. All products were characterized by elemental analysis, NMR and IR spectroscopy, and X-ray structure analysis. Particularly, 99 Tc NMR spectroscopy proved to be a valuable method for these types of technetium(I) compounds.

Reactions of (NBu4)­[MOCl4] complexes (M = Tc or Re) with an excess of hexafluoroacetylacetone (Hhfac) give products with a composition of (NBu4)­[MOCl3(hfac)] as bright yellow (Tc) or red (Re) solids. The products are stable as solids but rapidly decompose in solution. A number of related phenylimidorhenium­(V) complexes were synthesized starting from [Re­(NPhF)­Cl3(PPh3)2], where (NPhF)2– is a para-fluorinated phenylimido ligand. Products with compositions of [Re­(NPhF)­Cl2(PPh3)­(acac)], [Re­(NPhF)­Cl2(PPh3)­(hfac)], [Re­(NPhF)­Cl2(PPh3)­(tfac)], [Re­(NPhF)­Cl2(PPh3)­(naphtfac)], and [Re­(NPhF)­Cl2(PPh3)­(tbutfac)] (Hacac = acetylacetone, Htfac = trifluoroacetylacetone, Hnaphtfac = naphthoyltrifluoroacetylmethane, and Htbutfac = tert-butyro­yl­trifluoroacetylmethane) were isolated from reactions of the quite soluble [Re­(NPhF)­Cl3(PPh3)2] with the corresponding β-diketones and studied spectroscopically and by X-ray diffraction. The β-diketonates are coordinated in a meridional arrangement with the phenylimide. The formation of two isomers was detected for nonsymmetric β-diketones with a preference for the “equatorial” position for the more bulky substituents. Products with more than one chelating ligand were not obtained. The technetium complexes [Tc­(NPhX)­Cl3(PPh3)2] (X = p-F or p-CF3) were prepared from reactions of pertechnetate, PPh3, HCl, and substituted arylacetylhydrazines and isolated as green solids. They are sufficiently stable as solid but rapidly decompose in moist solvents upon hydrolysis of the Tc–N bonds. From reactions of [Tc­(NPh)­Cl3(PPh3)2] or [Tc­(NPhF)­Cl3(PPh3)2] in dry solvents, the complexes [Tc­(NPh)­Cl2(PPh3)­(hfac)] and [Tc­(NPhF)­Cl2(PPh3)­(hfac)] were prepared and isolated in crystalline form. An X-ray diffraction study shows that fluorination of the para position of the phenylimido ligand results in a slight lengthening of all bonds in the coordination sphere of technetium.

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