Hypophosphite hydrides

Hydrazoic acid Hydrides, volatile Hydrogen cyanide (unstabilized) Hydrogen (low pressure) Hydrogen peroxide (> 35% water) Magnesium peroxide Mercurous azide Methyl acetylene Methyl lactate Nickel hypophosphite Nitriles > ethyl Nitrogen bromide... 

Mixtures with calcium hydride or strontium hydride may explode readily, and interaction of the molten chlorate is, of course, violent. A mixture of syrupy sodium phosphinate ( hypophosphite ) and the powdered chlorate on heating eventually explodes as powerfully as glyceryl nitrate. Calcium phosphinate mixed with the chlorate and quartz detonates (the latter producing friction to initiate the mixture). Dried mixtures of barium phosphinate and the chlorate are very sensitive and highly explosive under the lightest confinement (screwed up in paper). 

Sulfenyl cldorides, sulfinic acids and sulfinyl chlorides were reduced in good yields by lithium aluminum hydride to disulfides [680], The same products were obtained from sodium or lithium salts of sulfinic acids on treatment with sodium hypophosphite or ethyl hypophosphite [507]. Sulfoxy-sulfones are intermediates in the latter reaction [507]. 

For some special methods for hydrides, see Exercise 44 (barium hypophosphite). Also, look up the preparation of NH3 and NH2NH2. 

According to H. Rose, the blue soln. of cupric hydroxide in cold hypophosphorous acid may remain unaltered for a long time and if very dil., it may even be heated without decomposition. If the soln. be evaporated in vacuo at a low temp., the copper is completely reduced as soon as the liquid is highly concentrated. C. A. Wurtz found that the soln. obtained by double decomposition of barium hypophosphite and copper sulphate at about 60° precipitates copper hydride— vide supra. Once blue crystals of copper hypophosphite, Cu(H2P02)2, were obtained they decomposed abruptly at 65°. According to R. Engel, this salt... 

A similar kinetic scheme can be applied to other reducing agents, such as boro-hydride (Red = BH ), hypophosphite (H2P02), and hydrazine (NH2NH2) where the electroactive species RH are [BH2OH ]ads, [HP02]ads, and [N2H3]ads, respectively (21,38). 

The decay involves attack by HO at phosphorus followed by hydride shift to cobalt or a direct hydride shift to cobalt from coordinated ammonia. The hydrido-cobalt intermediate so generated is believed to rapidly reduce another molecule of the hypophosphito complex in a post-rate-determining step to produce one equivalent of hypophosphite. 

This hypothesis was tested by adding other cobalt(III) complexes to compete with (NH3)5Co02PH22 + for the hydridocobalt. This caused the yield of H2P02- to decrease, as predicted by the scheme in Equations 8.64—8.66, where kh, kc, and kt are the specific rates for the hydride shift, reaction with Co(OPH20)2+, and trapping with Co(X)2 +, respectively. The ratio of phosphite to hypophosphite was used to evaluate the efficacy of the external traps. Among those tested, the complex (NH3)5Co(NCS)2+ was the most efficient. 

The chemical properties partly resemble those of white, partly those of red, phosphorus. It does not glow in the air, but does so in ozone. It is rapidly attacked by alkalies, giving hypophosphite and phosphine which is not spontaneously inflammable. It is coloured intensely black by ammonia. It dissolves in aqueous alcoholic potash giving red solutions from which acids precipitate a mixture of phosphorus and solid hydride. It dissolves in phosphorus tribromide to the extent of about 0-5 gram in 100 grams of the solvent at about 200° C. It is said to be non-poisonous its physiological properties probably resemble those of red phosphorus (q.v.). 

The codeposition of elements, such as phosphorus or boron, by direct interaction of the reducing agent with the catalytic surface was examined by some authors however, the interpretations are not completely satisfying. An indirect mechanism for hypophosphite reduction was proposed by Zeller and Landau.23 In this approach formation of phosphine as an intermediate and a direct interaction with radicals such as hydrogen atom H, hydride H , or NiOH was suggested.5, 12 24 26 However, the possible direct reduction of phosphite to phosphorous must also be considered. In favor of this hypothesis, there is the electrodeposition of NiP alloys from solutions containing Ni2+ and phosphite. The interaction of Ni2+ with the phosphite ions produces, at high pH, nickel phosphate precipitate when nickel ions are not adequately complexed. 

Nickel plating baths based on electroless deposition contain a reducing agent and a catalyst. The reducing agent acts as electron donor for the reduction of metal ions to the metal. Hypophosphite, formaldehyde, hydrazine, and boron hydride are suited for this. A colloidal Pd/Sn2+ solution usually serves as the catalyst. This solution is adsorbed to the material surface and catalyzes the deposition of a monolayer of the respective metal. Further plating occurs autocatalytically with the formation of hydride ions. 

Therefore, the analysis of the product distribution in the H2, HD, and D2 mixtures obtained during electrocatalytic hypophosphite oxidation on nickel electrode suggests that the hydride mechanism, assuming the release of hydride ion and instantaneous reaction with water, is unlikely due to HD content lower than the equilibrium values (hydride mechanism should lead to HD as a prevailing component [77]). Furthermore, this also puts to a question the electrochemical mechanism, according to which equilibrium H2, HD, and D2 mixtures must be formed due to the statistical recombination of H and D atoms for equally accessible electrode surface. To clarify this issue, computer simulations for the H2, HD, and D2 formed by the recombination of H and D atoms were performed. 

Suitable reducing agents are alkali metal borohydrides and alumino-hydrides, hydrazine (44), sodium dithionite, sodium hypophosphite (76a,... 

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