Cyano(fluoro)borate and cyano(hydrido)borate ionic liquids: low-viscosity ionic media for electrochemical applications.

The synthesis and detailed characterization of low-viscosity room-temperature ionic liquids (RTILs) and [BnPhP] salts with the cyano(fluoro)borate anions [BF(CN)] (MFB), [BF(CN)] (DFB), and [BF(CN)] as well as the new mixed-substituted anion [BFH(CN)] (FHB) is described. The RTILs with [EMIm] or [BMPL] as countercations were obtained in yields of up to 98% from readily available alkali metal salts and in high purities that allow application in electrochemical devices. Trends in thermal stability, melting and freezing behavior, density, electrochemical stability, dynamic viscosity, specific conductivity and ion diffusivity have been assessed and compared to those of the related tetracyanoborate- and cyano(hydrido)borate-RTILs.

Pentafluoroethylaluminates: A Combined Synthetic, Spectroscopic, and Structural Study.

Salts of the tetrakis(pentafluoroethyl)aluminate anion [Al(C F ) ] were obtained from AlCl and LiC F . They were isolated with different counter-cations and characterized by NMR and vibrational spectroscopy and mass spectrometry. Degradation of the [Al(C F ) ] ion was found to proceed via 1,2-fluorine shifts and stepwise loss of CF(CF ) under formation of [(C F ) AlF ] (n=1-4) as assessed by NMR spectroscopy and mass spectrometry and supported by results of DFT calculations.