Aminobis(diorgany1amino)phosphanes (R2N),PNH2 (R = iPr, c-Hex, Ph) (2a-c), were obtained by treatment of the corresponding chlorobis(diorgany1amino)phosphanes la-c with lithium amide in liquid ammonia. The transition metal phosphane complex (R2N)2(H2N)PNi(C0)3 (3) was prepared by reaction of 2a with tetracarbonylnickel. N-Complexation of 2a with trimethylalane affords the iminophosphorane-alane adduct (R2N),HP=N(H)A.lMe3 (4) by 1,2-H shift from the nitrogen to the phosphorus atom. The corresponding reaction with aluminium trichloride leads to the formation of the salt [(R2N)2HP=N(H)]2AICI,+[A1c141 (5), in w h c h two iminophosphorane moieties are linked by an AICl, bridge. Lithiation of 2a and subsequent reaction with titanocene dichloride result in nucleophilic replacement of one chlorine atom to give the phosphanylamido-substituted titanocene compound (R,N),P-N(H)Ti(Cl)Cp, @a), which rearranges to its P-hydroiminophosphorane tautomer (R,N),P(H) =NTi(C1)Cp2 (6b) on gentle heating. No isomerisation was observed in the case of N-borylated aminophosphane (R2N),P-NH-(9-BEN) (7), obtained by reaction of lithiated 2a with B-C1-9-BBN. The X-ray structure analyses of compounds 2b, c, 3, 4, 5, and 6a are discussed.In the past triaminophosphanes have been the subject of extensive studies [']. The ready availability of substituted triaminophosphanes (R2N)3P by reaction of PC13 with secondary aminesL21, their versatile reactivity and their properties as complex ligandsL3] characterise them as valuable synthons in organophosphorus chemistry. Amongst other reactions, oxidation to phosphorane~[~I and phosphonium salts ['], transesterification and transamination reactionsL41 as well as displacement reactions with hydrogen halides and boron halides furnishing the corresponding aminohalophosphaned6l have been described. In contrast, analogous triaminophosphanes derived from primary amines (RHN)3P lack thermal stability, due to facile amine elimination at ambient temperature, which leads to condensation reacti0ns[~1. Parent triaminophosphane (H2N)3P was postulated as an intermediate of the complete ammonolysis of phosphorus trichloride [']. However, there is no spectroscopic evidence known for this species. Elimination of ammonia results in the formation of not well-defined solids of varying composition. Mention should be made that thermally stable transition metal complexes (H2N)3PM(CO)S (M = Cr, Mo, W) are well-known [9]. Mixed aminophosphanes of the type (R,N)-,P(NH,), (x = 1, 2) have not been described so far. Formation of polymeric not well-defined products mas reported for the ammonolysis of (Ph2N)PC12[101, whilst oligomeric hydridophosphazenes were obtained by treatment of ammonia with (Me2N)J'CI, which themselves easily undergo condensation reactions at ambient temperature" ' 1.Recognizing the potential synthetic utilily of triaminophosphanes bearing NH2 groups as substituents with respect to an additional reactive site, we have focussed our attention on the stabilisation of such species by introduction of sterically prote...

Reactions of aminobis(diorganylamino)phosphanes (R2N)2PNH2 (R = iPr (a), Cy (b)) with Cp2MCl2 (M = Ti, Zr, Hf), CpTiCl3, and TiCl4 lead to the formation of the transition-metal complexes (R2N)2PN(H)MCp2Cl (M = Ti (1b), Zr (2a,b), Hf (3a,b)) (R2N)2P(H)NTiCpCl2 (8a,b), and (R2N)2P(H)NTiCl3 (10a,b), respectively. The influence of electronic effects of the metal fragment on the resulting equilibrium between the (NH)-phosphanylamido and the tautomeric (PH)-iminophosphorane form is presented in detail. Computational studies unambiguously confirm the experimental results. The molecular structures of 2a, 3a, and 8b have been determined by single-crystal X-ray diffraction.

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