Hypersilylated cyclodiphosphadiazanes and cyclodiphosphadiazenium salts

Abstract

Starting from tris(trimethylsilyl)silane the novel 2-chloro-3,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazenium-tetrachloridogallate salt (7) was prepared in a six step synthetic procedure including the synthesis of N-tris(trimethylsilyl)silyl-aminodichlorophosphine (4) and 1,3-dichloro-2,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazane (5). All intermediate products along the reaction path have been isolated and fully characterized. The thermally stable cyclo-diphospha-diazenium-tetrachloridogallate (7) represents an interesting example of a binary cyclic P(III)/N four-membered heterocyclic cation, with a di- and tricoordinated P atom and a delocalized bond along the NP(+)N unit. The structures of all compounds are discussed on the basis of experimental X-ray data. Moreover, for comparison the hitherto unknown 1-chloro-3-trifluoromethanesulfonato-2,4-bis-tris(trimethylsilyl)silyl-cyclo-diphosphadiazane (6) has been synthesized and fully characterized.

[P(μ‐NTer)]2: ein hochtemperaturstabiles Diradikaloid

“…[23] In [24a] 31 P-NMR-Experimente wurden durchgeführt, um Intermediate zu studieren. So wurde für die Reduktion von 1Hyp (Singulett bei d( 31 P) = 257 ppm) [19] die intermediäre Bildung des Diradikaloids 3Hyp (Quintett bei d = 334 ppm mit 2 J( 31 P-14 N) = 42 Hz) beobachtet. Für die analoge, aber viel schnellere Reaktion mit 1Ter wurde kein Intermediat beobachtet, sondern nur das 1,3 Diazaphosphaallyl 5Ter (5Ter: d( 31 P) = 357.6 ppm; vgl.…”

On the equilibrium between monomeric and dimeric iminochlorophosphanes R–N=P–Cl

“…The delicate equilibrium is best illustrated by the fact that Mes*N=P-Cl (Mes* = 9, Scheme 3) is observed as an iminochlorophosphane monomer in the solid state [20,21], while slightly smaller substitutents such as 2,6-diisopropylphenyl (6, Scheme 3) or the m-terphenyl (7, Scheme 3) allow dimerization. [5][6][7][15][16][17][18][19] Mes*N= P-Cl and the cation Mes*NP ? was first reported by Niecke et al [20,21].…”

“…They play a major role in preparative phosphorus-nitrogen chemistry, for example, in the preparation of macrocycles, polymers, main-group complexes, and ring transformation reactions or the generation of cyclic binary PN cations [2][3][4][5][6][7].…”

Dimers and Trimers of Diphosphenes: A Wealth of Cyclo‐Phosphanes

“…[1] In particular, we have always had great interest in NE chemistry, for example, the synthesis of cyclo-dipnictadiazanes [XE(m-NR)] 2 (A, X= (pseudo)halogen). [2][3][4][5][6][7][8][9][10] These four-membered ring systems are closely related to the highly reactive haloiminopnictanes RN=EX (B), since they can be regarded as formal dimers of the latter (Scheme 1). The stability of the monomeric iminopnictanes in comparison with the corresponding dimeric cyclo-dipnictadiazanes depends on the size of the sterically demanding substituent R. [11,12] For example, the supermesityl substituent (Mes* = 2,4,6-tri-tert-butylphenyl) favours the formation of the monomeric iminophosphane Mes*NPCl (1), which is stable in the solid state and in solution.…”

“…[18] Upon treatment with iodine, the similar tetraphosphenediide Tl 2 [Ter'PPPPTer'] (4 b, Ter' = 2,6-(2,6-diisopropylphenyl)phenyl) gave the bicyclotetraphosphane Ter'P 4 Ter' (5 a), which can be regarded as the formal reduction product of [XP(m-PTer')] 2 . [19] Concerning halogen-substituted diphosphenes, the formal monomers of the discussed cyclo-tetraphosphanes, the only reported example is Mes*PPCl (6), which was proposed to be the labile intermediate of the reaction of Mes*PPN(iPr) 2 (7) with various organolithium compounds (RLi) in the presence of HCl, leading to differently substituted diphosphenes of the type Mes*PPR. [20] However, no analytical information proving the formation of 6 was given in the publication, and thus its existence is uncertain.…”