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Updated: Sep 29, 2026
Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
Bis(trichlorophosphine)iminium salts, [Cl3P=N=PCl3]+, with transition metal halide counter-ions
Eric Rivard1, Andrew R McWilliams, Alan J Lough
1Davenport Research Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
Abstract:
The structures of four bis(trichlorophosphine)iminium [[Cl(3)P=N=PCl(3)](+); systematic name: trichloro[(trichlorophosphoranylidene)iminio]phosphorus(V)] salts, namely bis(trichlorophosphine)iminium hexachloroniobate, (Cl(6)NP(2))[NbCl(6)], (I), bis(trichlorophosphine)iminium hexachlorotantalate, (Cl(6)NP(2))[TaCl(6)], (II), bis(trichlorophosphine)iminium tri-micro-chloro-bis[trichlorotitanium(IV)], (Cl(6)NP(2))[Ti(2)Cl(9)], (III), and bis[bis(trichlorophosphine)iminium] di-micro-chloro-bis[tetrachlorozirconium(IV)], (Cl(6)NP(2))(2)[Zr(2)Cl(10)], (IV), have been determined. The P=N distances in the discrete [Cl(3)P=N=PCl(3)](+) moieties in structures (I), (II) and (IV) range from 1.5460 (14) to 1.5554 (16) A, and the P=N=P angles range from 136.8 (3) to 143.4 (4) degrees. The [Cl(3)P=N=PCl(3)](+) cation in (III) is disordered and the calculated geometries for the cation are therefore less reliable. Compounds (I) and (II) are isostructural and the metal anions have slightly distorted octahedral geometries. The anion in compound (III) consists of two distorted octahedral Ti centres linked by three micro (2)-Cl atoms, while in compound (IV), the dianion is derived from two distorted edge-shared ZrCl(6) octahedra.
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