Technetium(V) and rhenium(V) nitrido complexes with bis(diphenylthiophosphoryl)amide, [N(SPPh₂)]

Technetium(V) and rhenium(V) nitrido complexes of the compositions [MNL(2)] and [MN(Cl)(PPhMe(2))L] have been synthesized by reaction of Na[N(SPPh(2))(2)] and [MNCl(2)(PPh(3))(2)] or [MNCl(2)(PPhMe(2))(3)] complexes, respectively [M = Re or Tc; L = N(SPPh(2))(2)(-)]. The amide anion acts in all isolated complexes as a chelating ligand co-ordinated via the sulfur atoms. The complexes [TcN{N(SPPh(2))(2)}(2)], [ReN{N(SPPh(2))(2)}(2)] and [TcN(Cl)(PPhMe(3))(2){N(SPPh(2))(2)}] have been studied by X-ray crystallography. The bis-chelates are five-co-ordinate with the nitrogen atoms at the apexes of square pyramids. The Tc atom in [TcN(Cl)(PPhMe(2))(2){N(SPPh(2))(2)}] has a distorted-octahedral co-ordination sphere with Cl bonded trans to the nitrido function. The complex [ReN{N(SPPh(2))(2)}(2)] is the first five-co-cordinate nitride which reacts with BCl3 to form a nitrido bridge between rhenium and boron; [Re(NBCl3){N(SPPh(2))(2)}(2)] is characterized by a covalent N-B bond of 1.539(5) Angstrom. The Re-N multiple bond. distance is only slightly influenced by addition of the Lewis acid. The complex [ReN(Cl)(PPhMe(2))(2){N(SPPh(2))(2)}] reacts with BCl3 with substitution of N(SPRh2)(2)(-) and formation of the well known [Re(NBCl3)Cl-2(PPhMe(2))(3)]. The corresponding technetium complexes do not form Tc-N-B bridges upon reactions with BCl3. The [MN(Cl)(PPhMe(2))(2){N(SPPh(2))(2)}] (M = Tc or Re) complexes reacted with S2Cl2 to give thionitrosyl compounds with the metals in lower oxidation states; [Re(NS)Cl-2(PPhMe(2))(3)] and [Re(NS)Cl-3(PPhMe(2))(2)] have been characterized spectroscopically, [Tc(NS)Cl-3(PPhMe(2))(2)] was studied by X-ray diffraction and EPR spectroscopy. The phosphine ligands are trans to each other.