title: Synthesis of Functional Bis(pentafluoroethyl)silanes (C2F5)2SiX2, with X=H, F, Cl, Br, OPh, and O2CCF3.
abstract: As recently shown, the introduction of pentafluoroethyl functionalities into silicon compounds is of general interest due to an enhanced Lewis acidity of the resulting species. By this means, the synthesis of previously inaccessible hypervalent silicon derivatives is enabled. While an easy access to tris(pentafluoroethyl)silanes has already been published, synthetic strategies for the selective preparation of bis derivatives are yet unknown. In this contribution, a convenient protocol for the synthesis of functional bis(pentafluoroethyl)silicon compounds is presented. These compounds represent precursors for the synthesis of pentafluoroethylated polysiloxanes. Furthermore, they prove to be resistant to oxonium cations, which is a key feature for the preparation of stable pentafluoroethylsilic acids. Treatment of dichlorodiphenoxysilane with in situ generated pentafluoroethyl lithium leads to the corresponding bis(pentafluoroethyl)silane in high yields. (C2F5)2Si(OPh)2serves as a starting material for further functionalized bis(pentafluoroethyl)silanes. These silanes have been isolated and their reactivity towards N bases studied. The pronounced Lewis acidity of the obtained compounds has been documented by the formation of octahedral adducts with nitrogen donors such as 1,10-phenanthroline and acetonitrile.
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Nico
authors: N
authors: Schwarze
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Boris
authors: B
authors: Kurscheid
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Simon
authors: S
authors: Steinhauer
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Beate
authors: B
authors: Neumann
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Hans-Georg
authors: HG
authors: Stammler
authors: Merck KGaA, Frankfurter Straße 250, 64293, Darmstadt, Germany.
authors: Nikolai
authors: N
authors: Ignat'ev
authors: Centrum für Molekulare Materialien, Fakultät für Chemie, Anorganische Chemie II, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.
authors: Berthold
authors: B
authors: Hoge
keywords: Lewis acids; fluorine; halogens; perfluoroalkyl; silicon