Spectroscopic Studies of Tin(IV) and Mixed Oxidation State Tin(II)Tin(IV) Compounds

Abstract

<p>Proton n.m.r. data are presented for the solvolysis of hexamethylditin and tetramethylt in with fluorosulfuric acid. The tetramethylditin dication [(CH₃)₄Sn₂²⁺] is proposed as an intermediate in the suggested reaction sequence for the solvolysis of hexamethylditin with fluorosulfuric acid.</p> <p>The reaction between hexamethylditin and a series of carboxylic acids has been investigated. Compounds of empirical formula (CH₃)₂Sn(O₂CR) were prepared and formulated as the tetramethylditin carboxylates, (CH₃)₄Sn₂(O₂CR)₂. Infrared, Raman, ¹H and ¹³C n.m.r. and ¹¹⁹Sn Mössbauer data are presented for this series of compounds. The compounds have been shown to have a tetramethylditin moiety in which the carboxylate ligand bridges both tin atoms. The X-ray crystal structure of three of these compounds [R = CH₂Cl, CCl₃ and CF₃] are presented and the spectroscopic data evaluated in light of the crystallographic data. The X-ray crystal structure of {[(CH₃)₂Sn(O₂CCF₃)]O)₂ is also presented. The solvolysis of hexaphenylditin by a series of carboxylic acids was investigated. Seven novel compounds of empirical formula Sn(O₂CR)₃ were synthesized. Infrared, Raman and ¹¹⁹Sn Mössbauer spectra are reported for the series of Sn(O₂CR)₃ compounds which are best formulated as [Sn(II)Sn(IV)O(O₂CR)₄O(OCR)₂]₂. ¹¹⁹Sn Mössbauer data for Sn(O₂CR)₄ are also presented. The X-ray crystal structure of [Sn(II)Sn(IV)O(O₂CCF₃)₄]₂C₆H₆ has been determined and its relationship to other mixed oxidation state tin carboxylates examined.</p> <p>The solvolysis of hexaphenylditin by inorganic acids has been investigated. ¹¹⁹Sn Mössbauer spectra are presented for the products and vibrational (infrared and/or Raman) data for the isolated solids. Compounds of empirical formula SnF₃, Sn(SO₃CF₃)₃ and Sn(IV)O·SO₄Sn(II)(SO₃F)₂ are formulated as the polymers [Sn(II)Sn(IV)F₆]ᵪ, [Sn(II)Sn(IV)(SO₃CF₃)₆]ᵪ and [Sn(IV)O∙SO₄Sn(II)(SO₃F)₂]ᵪ. The Sn(SO₃R)₃ compounds where R = CH₃, C₂H₅ and OH were not isolated free of excess acid. ¹¹⁹Sn Mössbauer spectroscopy also showed that these products contain tin(II) and tin(IV) and the formulation of [Sn(II)Sn(IV)(SO₃R)₆]ᵪ is suggested.</p> <p>The interaction of SnF₂ with Sn(SO₃CF₃)₃ produced Sn₃F₂(SO₃CF₃)₆. ¹¹⁹Sn Mössbauer data together with infrared and Raman data have been interpreted in terms of a compound of formulation [(Sn(II)SO₃CF₃)₂Sn(IV)F₂(SO₃CF₃)₄]ᵪ.</p>