Chloride‐Induced Aufbau of Perchlorinated Cyclohexasilanes from Si2Cl6: A Mechanistic Scenario. Issue 30 (25th April 2014)

• Record Type: Journal Article
• Authors: Tillmann, Jan; Meyer, Lioba; Schweizer, Julia I.; Bolte, Michael; Lerner, Hans‐Wolfram; Wagner, Matthias; Holthausen, Max C.
• Is Part Of: Chemistry. Volume 20:Issue 30(2014)
• Page Start: 9234
• Page End: 9239
• Publication Date: 2014-04-25
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201402655
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A surprisingly simple preparative procedure, addition of Si₂Cl₆ to a solution of [<italic>n</italic>Bu₄N]Cl in CH₂Cl₂, leads to the formation of the chloride‐complexed cyclic dianions [Si₆Cl₁₂<bold>⋅</bold>2Cl]²⁻, [(SiCl₃)Si₆Cl₁₁<bold>⋅</bold>2Cl]²⁻, or [1, y‐(SiCl₃)₂Si₆Cl₁₀<bold>⋅</bold>2Cl]²⁻ (y=1, 3, 4), depending on the stoichiometric ratio of the reactants and the reaction temperature (25–85 °C). Below −40 °C the open‐chain oligosilane chloride adducts [Si₃Cl₉]⁻, [Si₃Cl₁₀]²⁻, [Si₄Cl₁₁]⁻, and [Si₆Cl₁₅]⁻ are formed, again depending on the reaction conditions chosen. All species were characterized by X‐ray crystallography. The underlying reaction mechanism is elucidated by DFT calculations. It incorporates all experimental findings and involves a few key elementary steps: 1) chloride‐induced liberation of SiCl₃⁻ or higher silanides, 2) their addition to neutral silanes yielding larger oligosilane chloride adducts, 3) dimerization of larger silanides to (substituted) cyclohexasilane dichloride adducts with inverse sandwich structure.</p> </abstract>