Nickel fluoride

Further improvements in anode performance have been achieved through the inclusion of certain metal salts in the electrolyte, and more recently by dkect incorporation into the anode (92,96,97). Good anode performance has been shown to depend on the formation of carbon—fluorine intercalation compounds at the electrode surface (98). These intercalation compounds resist further oxidation by fluorine to form (CF ), have good electrical conductivity, and are wet by the electrolyte. The presence of certain metals enhance the formation of the intercalation compounds. Lithium, aluminum, or nickel fluoride appear to be the best salts for this purpose (92,98). 

Nickel fluoride tetrahydrate [13940-83-5] Nip2 and its anhydrous counterpart, nickel fluoride [10028-18-9] Nip2, are the only known stable biaary... 

Historically, the annual consumption of nickel fluoride was on the order of a few metric tons. Usage is droppiag because nickel fluoride is Hsted ia the EPA and TSCA s toxic substance iaventory. Nickel fluoride tetrahydrate is packaged ia 200—500-lb (90.7—227-kg) dmms and the 1993 price was 22/kg. Small quantities for research and pilot-plant work are available from Advance Research Chemicals, Aldrich Chemicals, Johnson/Matthey, Pfalt2 and Bauer, PCR, and Strem Chemicals of the United States, Fluorochem of the United Kingdom, and Morita of Japan. 

Nickel fluoride is used in marking ink compositions (see Inks), for fluorescent lamps (4) as a catalyst in transhalogenation of fluoroolefins (5), in the manufacture of varistors (6), as a catalyst for hydrofluorination (7), in the synthesis of XeF (8), and in the preparation of high purity elemental fluorine for research (9) and for chemical lasers (qv) (10). 

K [14881-07-3], Rb [72151 -96-3], and Cs [72138-72-8]), are prepared by reaction of elemental fluorine, chlorine trifluoride, or xenon difluoride and a mixture of nickel fluoride and alkaH metal fluorides or other metal haHdes (16,17). If the fluorination is carried out using mixed fluorides, a lower temperature can be used, yields are quantitative, and the final products are of high purity. Bis(tetrafluoroammonium) hexafluoronickelate [6310540-8], (NE 2N iF6> prepared from Cs2NiF3 and NE SbE by a metathesis in anhydrous HE, is also known (18). 

Levee, J. et al., J. lnorg. Nucl. Chem., 1974, 36, 997-1001 Interaction may be explosive in the presence of finely divided nickel fluoride or silver difluoride, or nickel(III) oxide or silverQ oxide, or if initiated by local heating. The mechanism is discussed. 

Anhydrous nickel chloride, 17 110 Anhydrous nickel fluoride, 17 110 Anhydrous nickel halides, properties of, 17 HOt... 

Nickel dioxide, 77 107 Nickel double salts, 77 113 Nickel electrodes, 3 430 72 216 Nickel electroplating solutions, 9 818t Nickel extraction, 70 791 Nickel ferrite brown spinel, formula and DCMA number, 7 348t Nickel fibers, 77 108 Nickel fluoride complexes, 77 111 Nickel fluoride tetrahydrate, 77 109-110 Nickel fluoroborate, 77 111 Nickel fluoroborate hexahydrate, 4 157t, 158, 159... 

NiF2 NICKEL FLUORIDE 634.6103 -7.2704E+04 -2.0233E+02 4.4627E-02... 

Thus, it is beyond doubt that the fluorination reaction proceeds via an association between the organic substrate (or its protonated derivative) and the electrochemically generated nickel fluoride(s) on the anode surface. However, since the precise nature of this association, and the exact species involved, are not known, the next stage in the mechanism of fluorine substitution is not apparent and it has generally been the practice to make inferences from studies of product analyses. 

The essence of this theory on the mechanism of ECF is that reaction occurs via inorganic fluorinating agents generated at the anode these include nascent fluorine, molecular fluorine, or its loose complexes with nickel fluorides, and simple or complex forms of high valence nickel fluorides [62,65,169,178,179]. However, until the precise nature and structure of the active nickel anode surface is characterised the position remains a matter for conjecture. 

Instead, the authors suggest that the reaction takes place firstly by the formation of higher valence nickel fluoride(s) on the surface of the anode, and secondly, by specific adsorption of the organic on that surface. 

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