Date of Award
Doctor of Philosophy (PhD)
Antimony-121 Mössbauer spectra have been recorded at liquid-helium temperatures for a number of complex anions derived from SbF₃: M₂[SbF₅] (M₂ = Na₂, K₂, or N₂H₆); NaSbF₄; M[SbClF₃] (M = K or NH₄); Na[SbClF₃]·H₂O; M[Sb₃F₁₀] (M = Na, T1, or NH₄); M[Sb₄F₁₃] (M = K or Cs); and [NH₄]₄[Sb₅F₁₉]. The data were consistent with the known stereo-chemistry of these compounds in which the anitmony 5s electron pair is stereochemically active in a distorted AX₆E environment with a 3:3:1 arrangement or monocapped octahedron, the lone pair in the 1 position.
The ¹²¹Sb Mössbauer spectra of a number of [SbX⁻₄] (X = Cl, Br, or I) and [Sb₂X₉³⁻] (X = F, Cl, Br, or I) salts have been reported. Only [Sb₂F₉³⁻] shows a significantly large quadrupole splitting with the 5s electrons being stereochemically active.
The nature of the compounds of the series SbCl₅₋ᵪFᵪ have been in dispute in the literature for several years, but only SbCl₄F, which has been identified as a cis-fluorine bridged tetramer, and "SbCl₂F₃", which has been shown to exist with the ionic formulation [SbCl₄⁺][Sb₂Cl₂F₉⁻], are well characterized. It was found in this work that a fluorine bridged [SbCl⁺₄][Sb₂Cl₂F₉⁻] species in the solid state is more consistent with the chemistry of this compound. The previously unknown Sb₃Cl₁₀.₇₅F₄.₂₅ was prepared and found from X-ray crystallography to exist as a disordered cis-fluorine bridged trimer in the solid state. SbCl₃F₂ was prepared and characterized as a cis-fluorine bridged tetramer in the solid state. An attempt to prepare SbClF₄ always resulted in the formation of [SbCl⁺₄][Sb₂F₁₁⁻], which previously had been little studied. These SbCl₅₋ᵪFᵪ compounds have been characterized using Mössbauer and Raman spectroscopy, and Mass spectrometry. The reaction of SbCl₄F with strong Lewis acids was also investigated. SbCl₄F was found to form [AsCl₄⁺]-[SbF⁻₆] with AsF₅, [SbCl₄⁺][Sb₂Cl₂F⁻₉] with SbF₅, and a polymeric complex of the type [SbCl₄F.(NbF₅)ᵪ] (x = 1, or 2) with NbF₅.
The reaction of alkali metal halides with antimony(V) halides in liquid SO₂ at room temperature yielded the salts: M[SbCl₆] (M = Na or K); Na[SbCl₄F₂]; Na[SbCl₂F₄]; and M[SbF₆] (M = K or Cs). The variation of ¹²¹Sb Mössbauer isomer shifts and quadrupole coupling constants are discussed in terms of molecular geometry. The salt Na[SbCl₄F₂] has been shown by Raman spectroscopy to exist as the trans isomer in the solid state.
Mössbauer data are reported for pure SbF₅ and SbCl₅, and when intercalated into graphite the spectra show that these halides do not enter the graphite lattice without some reduction to Sb(III) occurring.
Data are reported for a number of SbF₅·X adducts, where X represents SbF₃, AsF₃, or SO₂ at 4ºK. The Mössbauer parameters of SbF₅·SbF₃ (type A), and the SbF₅-SbF₃ 1:1 adduct, [Sb₂F²⁺₄][SbF₆⁻]₂, do not support the contention that these forms are identical.
The complex anions of [Te₂Se₂²⁺][Sb₃F₁₄⁻][SbF₆⁻] and [Te₃.₃Se₀.₇²⁺]-[Sb₃F₁₄⁻][SbF₆⁻] have also been investigated by the Mössbauer method. The magnitude of the n values calculated for the Sb(III) sites are interpreted in terms of the varying asymmetry about the principle axis, which passes through the lone pair of electrons.
Ballard, Jack George, "Spectroscopic Studies of Antimony III and V Halide Complexes" (1977). Open Access Dissertations and Theses. Paper 3837.