Phosphines electrolytic reduction

Phosphonium (and quasi-phosphonium) salts generate phosphines under electrolytic reduction (Table 7). Mercury, lead, platinum, tin, copper and aluminium172 cathodes were tried, mercury being the most often used173. Product dependence on cathode material, current, density and solvent has been observed174. In the case of unsymmetrical... 

The majority of nickel(I) complexes contain phosphine ligands, or closely related ones, and have tetrahedral or tbp structures. They are paramagnetic as expected for d9 configurations. The tetrahedral compounds NiX(PPh3)3 (X = Q, Br, and I) were among the first of this sort to be isolated they decompose only slowly in air and are stable for long periods of time under nitrogen. Electrolytic reductions of... 

In contrast to phosphine oxides, whereby the phosphoryl group is reduced, the reduction of phosphonium salts involves cleavage of a P—C bond. There are several ways this can be achieved, including base-induced cleavage, thermal decomposition, hydride or electrolytic reduction.2... 

Electrolytic reduction of quaternary halides proceeds with retention of configuration and the method can be used to obtain optically active (chiral) phosphines (Chapter 13.2). 

Using a method of electrolytic reduction, Horner [3] in 1961 obtained optically active phosphines from the corresponding phosphonium salts. These reactions proceed with retention of configuration (13.57) and the products racemise only slowly in boiling toluene. 

ESR spectroscopy as products generated during electrochemical oxidation of PR3 compounds in solution the initially-formed phosphinium radical cation reacts rapidly with a further molecule of phosphine Phosphonium radical anions are the least well characterised of all phosphorus radicals. Electrolytic reduction of PPh3 in CH3CN, at a dropping mercury cathode, produced biphenyl and diphenylphosphonic add. The radical anion was presumed to be an intermediate ... 

An interesting reduction of aromatic nitro compounds which uses glucose in an alkaline medium (equation 7) has received little attention. The advantages of this reaction include high yields, rapid rate and ease of product isolation from oxidation by-products. Other reagents which bring about the reduction of nitroanenes to azoxy compounds include potassium borohydride, sodium arsenate, phosphine and yellow phosphorus. Electrolytic methods have also been utilized. ... 

The electrolytic production, in all its variation, (different anode and cathode material different electrolytes, etc.) of phosphine is described in several patents It is believed that the reduction by this method proceeds via formation of the... 

The phosphoric acid electrolyte of the acid fuel cell is far from optimum, particularly because of the low catalytic activity of platinum and other similar catalysts for 02 reduction in this electrolyte. A promising approach is to replace this electrolyte with new perfluorinated acids, which have high 02 solubility and do not adsorb on the catalyst surface. This should lead to much-improved performance of the air cathode. Work is in progress in several laboratories on the preparation of these new acids (e.g., perfluorinated sulfonic, phosphonic, and phosphinic acids) as a replacement for phosphoric acid. Reasonably high conductivity at high ratios of acid to water is also an important consideration. 

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