Tris(pentafluoroethyl)silanol Derivatives and the Lewis Amphoteric Tris(pentafluoroethyl)silanolate Anion, [Si(C₂ F₅ )₃ O].

ABSTRACT: 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(C₂ F₅ )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(C₂ F₅ )₃ O]^- . In order to examine such Lewis amphoteric behavior, we first developed a strategy for the synthesis of the corresponding silanol Si(C₂ F₅ )₃ OH, which readily condenses at room temperature to the hexakis(pentafluoroethyl)disiloxane, (C₂ F₅ )₃ SiOSi(C₂ F₅ )₃ . Deprotonation of Si(C₂ F₅ )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(C₂ F₅ )₃ O}₂ ]^2- , implies Lewis amphoteric character of the monomeric [Si(C₂ F₅ )₃ O]^- anion.

SUBMITTER: Tiessen N 

PROVIDER: S-EPMC8453507 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature