Synthesis, Properties, and Application of Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)(4)](-)

摘要

Weakly coordinating anions (WCAs) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)(4)](-), a new WCA, is accessible by treatment of [GaCl3(dmap)] (dmap=4-dimethylaminopyridine) with LiC2F5. The anion [Ga(C2F5)(4)](-) proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C2F5)(4)](-) were synthesized with cations such as [PPh4](+), [CPh3](+), [(O2H5)(2)(OH2)(2)](2+), and [Li(dec)(2)](+) (dec=diethyl carbonate). Thermolysis of [(O2H5)(2)(OH2)(2)][Ga(C2F5)(4)](2) gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C2F5)(3)(OH2)(2)]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X-ray diffraction, and elemental analysis. Furthermore, an outlook for the application of [Li(dec)(2)][Ga(C2F5)(4)] as a conducting salt in lithium-ion batteries is presented.