Technetium(V) and rhenium(V) nitrido complexes of the compositions [MNL2] and [MN(Cl)(PPhMe2)L] have been synthesized by reaction of Na[N(SPPh2)2] and [MNCl2(PPh3)2] or [MNCl2(PPhMe2)3] complexes, respectively [M = Re or Tc; L = N(SPPh2)2-]. The amide anion acts in all isolated complexes as a chelating ligand co-ordinated via the sulfur atoms. The complexes [TcN{N(SPPh2)2}2], [ReN{N(SPPh2)2}2] and [TcN(Cl)(PPhMe2)2-{N(SPPh2)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)(PPhMe2)2{N(SPPh2)2}] has a distorted-octahedral co-ordination sphere with Cl bonded trans to the nitrido function. The complex [ReN{N(SPPh2)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(SPPh2)2}2] is characterized by a covalent N-B bond of 1.539(5) Å. The Re-N multiple bond distance is only slightly influenced by addition of the Lewis acid. The complex [ReN(Cl)(PPhMe2)2{N(SPPh2)2}] reacts with BCl3 with substitution of N(SPPh2)2- and formation of the well known [Re(NBCl3)Cl2(PPhMe2)3]. The corresponding technetium complexes do not form Tc-N-B bridges upon reactions with BCl3. The [MN(Cl)(PPhMe2)2{N(SPPh2)2}] (M = Tc or Re) complexes reacted with S2Cl2 to give thionitrosyl compounds with the metals in lower oxidation states; [Re(NS)Cl2(PPhMe2)3] and [Re(NS)Cl3(PPhMe2)2] have been characterized spectroscopically, [Tc(NS)Cl3(PPhMe2)2] was studied by X-ray diffraction and EPR spectroscopy. The phosphine ligands are trans to each other.
