Trifluorophosphine acidity

IR spectra, 22 177-179 Raman spectra, 22 178, 179 triazole and triazolate complexes, 32 180 trifluoride, structure, 27 90, 91, 92, 95, 97 trifluorophosphine complexes cyclopentadienyl, 29 103 hexakis anion, 29 53-54 [Ni4(0CH3)4(acac)4(CH3OH4)l, 43 323 Nitramide, reaction mechanisms, 22 138, 139 acid catalysis, 22 139... 

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. 

An interesting feature of hydrido transition metal-PF3 complexes is that apart from a few dinuclear systems (Section VI) only mononuclear systems are so far known and there is as yet no corresponding chemistry analogous to that of polynuclear carbonyl hydrido compounds. The trifluorophosphine metal hydrido compounds are usually highly acidic and can readily form metallate ions such as [M(PF3)m]x and [MH(PF3) r. 

An interesting synthesis of zero-valent ruthenium phosphine-trifluorophosphine complexes has been reported (2, 4) (method I) via reductive elimination of acetic acid from the ruthenium(II) hydrido acetato complex [RuH(C02Me)(PPh3)3]. 

The slow hydrolysis of trifluorophosphine compared with the other trihalogenophosphines has been long known (282) and the gas may be washed with water without any significant loss. This offers a convenient way of removing small amounts of HF and SiFi from trifluorophosphine during its preparation. The ultimate products of hydrolysis of trifluorophosphine are hydrogen fluoride and orthophosphorous acid (282). 

Iodoform also reacts with hydridotetrakis(trifluorophosphine)cobalt (I) in pentane at 0°C 164) and the acidic hydrogen is also easily replaced... 

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