Electrochemical fluorination of room temperature molten salt

The electrical conductivities of the (CH3)(4)NF.mHF melts (m = 3.5, 4.0, 4.5, 5.0, and 5.5) increased with increasing the m value. In contrast, the viscosities of the melts decreased largely in the range of the m values between 3 and 4 and then decreased linearly with increasing the in value. The IR study revealed that a free HF molecule as well as ions such as (HF)F-, (HF)F-2(-), and (HF)(3)F- existed in the (CH3)(4)NF.mHF melts (m > 3.0). The H-1-NMR measurement also indicated that the various forms of the species and the ions having HF existed in the melts and that the number of HF coordinating to F ion in the melts increased with the m value. In electrolysis of the melt at room temperature, the anode gas generated on the Ni, the Ni-NiO coating Ni, and the LiNiO2 coated Ni sheets was composed of CF4, NF3, C2F6, CHF3, (CF3)(3)N, C2F5N(CF3)(2), and a few kinds of partial fluorinated amines. The formation ratio of a partial fluorinated amine to the overall anode gas decreased with increasing the m value. The best yield of (CF3)(3)N was obtained with the LiNiO2 coated Ni sheet anode polarized at 4.0 V in the (CH3)(4)NF.5HF melt.