[TcII(NO)(trifluoroacetate)4F]2− – synthesis and reactions†
Fluoridotetrakis(trifluoroacetato)nitrosyltechnetate(II) was prepared by the dissolution of Cs2[Tc(NO)F5] in trifluoroacetic acid and addition of (NBu4)F·3H2O. The compound crystallizes as a mixed Cs+/NBu4+ salt in the form of green crystals. Unlike the [Tc(NO)F5]2− salts, the product is soluble in organic solvents and can be used as a precursor for ongoing ligand exchange procedures with organic ligands. The corresponding reactions with triphenylphosphine (PPh3), 1,2-bis(diphenylphosphino)ethane (DPPE) or pyridyldiphenylphosphine (pyPPh2) give technetium(I) complexes of the compositions Cs[Tc(NO)(PPh3)2(CF3COO)2F], [Tc(NO)(DPPE)2(OOCCF3)](PF6) and [Tc(NO)(κN,P-pyPPh2)(κP-pyPPh2)(CF3COO)2]. The products were studied spectroscopically and by X-ray diffraction. The 99Tc NMR resonances of the novel Tc(I) nitrosyls appear between −627 and +952 ppm, which is at a remarkably high field and in the range where normally the signals of Tc(III) compounds are observed.