Nitrogen fluorides synthesis

CoF is used for the replacement of hydrogen with fluorine in halocarbons (5) for fluorination of xylylalkanes, used in vapor-phase soldering fluxes (6) formation of dibutyl decalins (7) fluorination of alkynes (8) synthesis of unsaturated or partially fluorinated compounds (9—11) and conversion of aromatic compounds to perfluorocycHc compounds (see Fluorine compounds, organic). CoF rarely causes polymerization of hydrocarbons. CoF is also used for the conversion of metal oxides to higher valency metal fluorides, eg, in the assay of uranium ore (12). It is also used in the manufacture of nitrogen fluoride, NF, from ammonia (13). 

All nitrogen fluorides are very reactive, often dangerous species, generally powerful oxidizers. Such compounds as NF3 (5F = +143) and N2F4 would virtually never be encountered in an organic synthesis laboratory, and no NMR data have even been reported for the latter compound. NF3 has a pyramidal structure, with F—N—F bond angles of -102°. 

A direct synthesis of N2F2 in low yield and admixed with other nitrogen fluorides has been reported from the irradiation of N2-F2 mixtures with ra-y-radiation from a nuclear reactor admixed with other high-energy radiation from uranium fission products (85). There is also a radiochemical synthesis of N2F2 (1.5%) and NF3 (42%) when an N2-F2 mixture is irradiated with 30-MeV electrons in an electron linear accelerator (86). Reaction of fluorine diluted with N2 and NH3 also gives some N2F2 (159,213). 

Plasma-Chemical Synthesis of NF3 and Other Nitrogen Fluorides... 

Control of the pH and temperature of the precipitating solution is important to provide optimised conditions for stoichiometric, homogeneous, fluorhydroxyapatite formation. Similar conditions and set-up can be used for the synthesis of fluoride-substituted apatite crystals with varying size, crystallinity and morphology depending on the preparation temperature [124] a purge of the synthesis system with nitrogen gas ensures the preparation of carbonate-free fluorhydroxyapatite at ambient temperature [125]. 

Nucleophilic displacement of chloro groups by fluoride was accomplished under pyrolysis conditions with potassium fluoride the chloro (and bromo) precursors are available by ring-synthesis [78HC(33)1 79CB1529 84MI7]. Halogens next to annular nitrogens are the most easily displaced,... 

Synthesis of four-membered heterocycles with two nitrogen atoms by C-C bond formation was reported in the early 1990s via a cesium fluoride-mediated cyclization of azine 236 (Scheme 36) <1991IC535>. 

Direct synthesis of NF3 from nitrogen and fluorine was not effected until 1964, when Maya obtained yields up to 30% on passing an N2-F2 mixture at a pressure of 20- 40 mm through an electric discharge in a tube cooled to — 196°C (207). This method is similar to that used in the synthesis of oxygen fluorides from the elements (144,259), except that in the latter case different oxygen fluorides are produced by changing the stoichiometry of the mixture of reactants, whereas with N2-F2 mixtures only NF3 results. 

The direct conversion of the acid fluoride into the alkyl iodide by reaction with lithium iodide was also successfully applied to the synthesis of nitrogen-containing pcrfluoroalkyl iodides (Table 3). -... 

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