The Nitrogen Fluorides and Some

The Nitrogen Fluorides and Some Related Compounds H. J. Emeleus, Jean ne M. Shreeve, and R. D. Verma... 

Table 6.4 contains some bond length and bond angle data for the hydrides, fluorides and chlorides of nitrogen, phosphorus and arsenic. The differences in the electronegativity coefficients (Allred-Rochow) in the compounds are also given. 

Considerable data have been assembled concerning the physical and chemical properties of the nitrogen fluorides (6), yet a review of the literature revealed no systematic study of die reactions of these compounds with water. Although some isolated experiments relating to the hydrolysis of these gases have been reported (6), the results have not been critically analyzed. Usually these hydrolytic reactions were reported as observations noted during the investigation of other properties. 

High-purity nitrogen oxide trifluoride has been obtained by fluorolysis of the nickel salt. By first forming this compound, troublesome impurities such as carbon tetrafluoride (from the fluorine) and nitrous oxide (from the nitric oxide) are avoided. The mixture, with nitrosyl fluoride and some nitryl fluoride, is purified chemically by titrating the gas with boron trifluoride, when both of the strongly basic oxyfluorides are removed as fluoroborates ... 

Addition of an aqueous solution of the fluoride to one of the nitrate unexpectedly gave no precipitate of magnesium fluoride, and the solution was allowed to evaporate, first at ambient temperature, and then in a warm place, giving a wet white solid. While being manipulated with a spatula, this exploded with some violence, brown fumes were evolved and the solid was transformed into a dry tan-coloured powder. It was thought that oxidation of tin(II) to (IV) had occurred, the nitrate being reduced to nitrogen oxide. 

It was decided to study the system tetrakis (trifluorophosphine) nickel- (0) -ammonia (23) in some detail a smooth reaction was observed when the complex, condensed on excess ammonia at liquid air temperature, was allowed to warm up gradually. Precipitation of colorless crystals, identified as ammonium fluoride in almost stoichiometric amount, based on complete ammonolysis of the phosphorus-fluorine bonds, was observed at temperatures as low as —90° to —80°. Removal of the ammonium fluoride by filtration at temperatures not higher than —50°, and subsequent slow evaporation of the ammonia from the filtrate invariably led to a brown-yellow solid, although a colorless, crystalline material was formed initially. The product was decomposed almost instantaneously by water with precipitation of elemental nickel. Analysis of the hydrolyzate obtained in aqueous hydrochloric acid revealed a nickel-phosphorus-nitrogen atom ratio close to 1 4 4, corresponding to an apparently polymeric condensation product. 

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