Stannylphosphonium Cations

Abstract

Rare examples of PSn bonded cations (see structure; purple Al, gray C, green Cl, orange P, red Sn) are formed in reactions of Me3P or Me2PCH2CH2PMe2 with Me3SnCl or nBu2SnCl2 in the presence of a halide abstracting agent. The demonstrated versatility of the reactions, structures and bonding arrangements bodes well for the development of a diverse PSn chemistry by exploiting coordination chemistry for PSn bond formation.

Reductive Dehydrogenation of a Stannane via Multiple Sn−H Activation by Frustrated Lewis Pairs

“…The shift is in the range of tetra‐substituted stannanes and the predicted 119 Sn chemical shift for a computationally determined structure of this cation is in reasonable agreement (δ Sn,calcd =−382 ppm). The 31 P NMR signal for [Ar*SnH 2 (P t Bu 3 )] + ( 1 ) is observed at δ P =72.1 ppm with tin satellites revealing a very small 1 J Sn‐P coupling of only 32 Hz which is an order of magnitude smaller than in [Me 3 PSnMe 3 ] + . The formation process of 1 resembles Burford's approach to stannylphosphonium cations …”

“…The 31 P NMR signal for [Ar*SnH 2 (P t Bu 3 )] + ( 1 ) is observed at δ P =72.1 ppm with tin satellites revealing a very small 1 J Sn‐P coupling of only 32 Hz which is an order of magnitude smaller than in [Me 3 PSnMe 3 ] + . The formation process of 1 resembles Burford's approach to stannylphosphonium cations …”

“…The elusive Ar*SnH then further reacts with a second equivalent of FLP forming the neutral base‐stabilized stannylene (step IIIa , Scheme ) and hydride abstraction (step IV ) . In the second pathway, IIb , the phosphine attacks at the Sn atom forming the dihydrostannyl cation [Ar*SnH 2 (P t Bu 3 )] + ( 1 ) in a substitution reaction similar to the formation of Burford's [Me 3 SnPMe 3 ] + . According to 31 P EXSY‐NMR spectra, this adduct formation is irreversible.…”

Neutral and cationic phosphine and arsine complexes of tin(iv) halides: synthesis, properties, structures and anion influence

“…5,6 The formation of cationic complexes would be expected to enhance the Lewis acidity of the tin centre, and examples of halo-or organo-tin cations with polydentate and pincer ligands have been described. [7][8][9][10][11][12] MacDonald et al 11 2+ . In the present work we have explored the reaction of tin(IV) halides with a series of mono-and bi-dentate phosphine, arsine and stibine ligands and the abstraction/replacement of some of the halides from the resulting complexes by other weakly coordinating anions, including triflate ([CF 3 SO 3 ] − ) via treatment with trimethylsilyltriflate, [AlX 4 ] − via addition of aluminium trihalides and using the large diffuse [BAr F ] − anion, via addition of its Na + salt (BAr F = [B{3,5-(CF 3 ) 2 C 6 H 3 } 4 ] − ).…”

[GaX2(dmpe)2][GaX4] (X = Cl, Br, I): a synthetic, solid state, and computational study

“…The chemistry of aluminum and gallium are most developed in this context, [1][2][3][4][5] and the presence of a cationic charge naturally enhances the Lewis acidity of the acceptor site, which we have exploited to realize examples of phosphine and pyridine complexes of pnictogen centres (Group 15) and tetrael centres (Group 14). [6][7][8][9] While reports of solid state structures for phosphine complexes of gallium are relatively rare, 10 Levason et al revealed structural diversity for diphosphine complexes of gallium, 5 with the expectation that a four coordinate tetrahedral environment is favoured for gallium. We now report that reactions of gallium(III) halides with the prototypical ligand 1,2-…”