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Tris(pentafluoroethyl)silanol Derivatives and the Lewis Amphoteric Tris(pentafluoroethyl)silanolate Anion, [Si(C 2 F 5 ) 3 O] −
Author(s) -
Tiessen Natalia,
Schwarze Nico,
Keßler Mira,
Neumann Beate,
Stammler HansGeorg,
Hoge Berthold
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202101845
Subject(s) - chemistry , silanol , lewis acids and bases , phosphazene , tris , deprotonation , monomer , alkyl , steric effects , polymer chemistry , medicinal chemistry , ion , organic chemistry , polymer , catalysis , biochemistry
While alkyl‐substituted siloxanes are widely known, virtually nothing is known about perfluoroalkyl siloxanes and their congener species, the silanols and silanolates. We recently reported on the tris(pentafluoroethyl)silanide ion, [Si(C 2 F 5 ) 3 ] − , which features Lewis amphoteric character deriving from the pentafluoroethyl substituents and their strong electron‐withdrawing properties. Transferring this knowledge, we investigated the Lewis amphoteric behavior of the tris(pentafluoroethyl)silanolate, [Si(C 2 F 5 ) 3 O] − . In order to examine such Lewis amphoteric behavior, we first developed a strategy for the synthesis of the corresponding silanol Si(C 2 F 5 ) 3 OH, which readily condenses at room temperature to the hexakis(pentafluoroethyl)disiloxane, (C 2 F 5 ) 3 SiOSi(C 2 F 5 ) 3 . Deprotonation of Si(C 2 F 5 ) 3 OH employing a sterically demanding phosphazene base allows the characterization of the first example of a dimeric triorganosilanolate: the dianionic hexakis(pentafluoroethyl)disilanolate, [{Si(C 2 F 5 ) 3 O} 2 ] 2− , implies Lewis amphoteric character of the monomeric [Si(C 2 F 5 ) 3 O] − anion.