Nouveaux Cations Phosphores A Enchainement P—N—PN+(N = 1.2) Comportant Les Coordinences 2,3 Et 4 Du Phosphore

Azidophosphenium cations: versatile reagents in inorganic synthesis

This work describes the synthesis and characterization of a series of iminophosphorane-substituted phosphenium cations of the type [R2NPNP(Cl)2NPNR'2][GaCl4] [R = iPr; R' = iPr (7[GaCl4]), SiMe3 (8)], which are directly derived from azidophosphenium salt [iPrNPN3][GaCl4] (2iPr[GaCl4]) and the corresponding chlorophosphane R2NPCl2. The reactivity of 7[GaCl4] toward 2,3-dimethylbutadiene (dmb) and 2,2'-bipyridine (bipy) was investigated, resulting in the formation of 7-dmb[GaCl4] and 7-Cl. In addition, self-condensation of [(Me3Si)2NPN3][GaCl4] (2SiMe3[GaCl4]) was studied in detail, and [(Me3Si)2NPNP(XY)N(SiMe3)2][GaCl4] [X = Cl; Y = Cl (13), N3 (14)] were determined as products on the basis of (31)P NMR spectroscopy. The reaction of 2SiMe3[GaCl4] with [(Me3Si)2NPCl][GaCl4] (1SiMe3[GaCl4]) yielded an unprecedented bicyclic 1,3,2λ(3),4λ(5)-diazadiphosphetidine (15), which was formed via a GaCl3-assisted Me3SiCl elimination starting from 13. Furthermore, cations of the type [R2NPNPR'3][GaCl4] [R = iPr; R' = cHex (19)] were obtained by the effective combination of 2R[GaCl4] (R = iPr, SiMe3) with PR'3 (R' = Ph, cHex). Azidochlorophosphanes R2NP(N3)Cl [R = iPr, SiMe3 (20R)] are shown to be accessible when 2R[GaCl4] was combined with bipy. All new compounds were fully characterized by means of X-ray, vibrational spectroscopy, CHN analysis, and NMR experiments. All compounds were further investigated by means of density functional theory, and the bonding situation was accessed by natural bond orbital analysis.

On the synthesis and reactivity of highly labile pseudohalogen phosphenium ions

The synthesis and characterization of salts bearing highly labile pseudohalogen-substituted aminophosphenium cations of the type [(Me3Si)2NPX][GaCl4] (X = NCO, NCS, O(SiMe3)) and their respective reactivity toward Lewis bases (4-dimethylaminopyridine, dmap) and dienes (2,3-dimethyl-1,3-butadiene, dmb; 1,3-cyclo-hexadiene, chd) are described. As π-acidic species, aminophosphenium cations react with dmap at low temperatures to yield adduct salts of the type [(Me3Si)2NP(dmap)X][GaCl4] (X = Cl, N3, NCO) which were fully characterized. In the reaction with dienes at -50 °C, salts bearing phospholenium cations were obtained that could be structurally characterized. The crystal structures of novel 7-phosphanorbornenium cations of the type [(Me3Si)2NP(C6H8)X][GaCl4] (X = Cl, N3, NCO) are reported. All compounds were further investigated by means of density functional theory, and the bonding situation was accessed by Natural Bond Orbital (NBO) analysis.