Synthesis and reactivity of cyclo-tetra(stibinophosphonium) tetracations: redox and coordination chemistry of phosphine–antimony complexes

Abstract

Reactions of trialkylphosphines with antimony(iii) triflates yield catena-antimony(i) cations revealing a new reductive elimination/oxidative coupling reaction for P–Sb coordination complexes.

Bond fission in monocationic frameworks: diverse fragmentation pathways for phosphinophosphonium cations

“…S19d in the ESI†) indicate that β-hydride elimination, which yields extremely rare examples of H-phosphinophosphonium cations, is in fact the most preferred dissociation pathway for R = t Bu in the gas phase as determined from the appearance potential and intensity of the resulting fragments. The observation of [Cy(H)PPMe 3 ] + by NMR spectroscopy30 and the recent isolation of NHC-stabilized phosphenium cations31 of the form [R(H)P] + (R = H, Me, or CPh 3 ) provide experimental evidence for the stability of [R(H)PPR′ 3 ] + cations (R, R′ = alkyl or aryl) and supports the proposed β-hydride elimination pathway. Interestingly, β-hydride elimination is ubiquitous in transition metal coordination chemistry but has been found only rarely in main group complexes 32…”

Complexes of Stiboranium Mono‐, Di‐, and Trications

“…Signals corresponding to chlorobenzene were observed in the 13 CNMR spectrumo ft he reaction mixture, indicating that reduction of Sb V to Sb III is associated with the oxidative coupling of Ph and Cl. [6,14,15] The redox behavior of Ph 2 SbCl 3 in the presence of bipy and TMSOTf contrasts the apparent redox stability of the previously reported [Ph 3 Sb(bipy)][OTf] 2 , [6,7] whichc ontains af ormald ication. [12,13] Moreover, cationic phosphinec omplexes of Sb III and Sb V centers have been observed to oxidatively couple R 3 Pt of orm diphosphonium cations (R = Me, Et, Pr).…”

“…[12,13] Moreover, cationic phosphinec omplexes of Sb III and Sb V centers have been observed to oxidatively couple R 3 Pt of orm diphosphonium cations (R = Me, Et, Pr). [6,14,15] The redox behavior of Ph 2 SbCl 3 in the presence of bipy and TMSOTf contrasts the apparent redox stability of the previously reported [Ph 3 Sb(bipy)][OTf] 2 , [6,7] whichc ontains af ormald ication. We speculatet hat the imposition of a tricationic charge is avoided by reductive elimination of PhCl from [Ph 2 Sb(bipy)Cl][OTf] 2 .…”

Synthesis, Structure, and Reactivity of Ga‐Substituted Distibenes and Sb‐Analogues of Bicyclo[1.1.0]butane

“…Comparable Sb−Sb bond lengths were observed in phosphine‐stabilized, cationic Sb 4 rings of the type [(R 3 P) 4 Sb 4 ][OTf] 4 [R=Me 2.8354(6)‐2.8797(5) Å; R=Et 2.838(2)‐2.884(2) Å], [(Me 3 P) 3 Sb 4 R 2 ] [2.8209(5)‐2.8612(5) Å], and in the homoatomic Sb 4 2− (av. 2.750 Å) and Sb 7 3− polyanions (av.…”