Phosphorus halides phosphides

There are several different preparations of metal phosphides. Secondary phosphines can be metallated by strong bases such as butyl-lithium or alkali metals (Scheme 5). Primary phosphines can be doubly lithiated using LDA or BuLi.11 Both the anion and dianion metal phosphides can be generated in situ before adding the electrophile into the same pot.12,13 Phosphorus halides can be metallated using lithium metal. 

The element combines with many nonmetals upon heating, forming its binary salts. It combines with halogens when heated, forming the corresponding halides. Heating with phosphorus, sulfur, and tellurium produces phosphide, CdsP2 sulfide, CdS and teUuride, CdTe salts, respectively. 

Arsenic Phosphides.—Black or brown products of indefinite character, to which have been ascribed the formulae AsaP 4 and AsP,5 have been obtained by various methods, such as (1) by heating the elements together,6 (2) by allowing phosphorus to stand in solutions of arsenious acid,7 and (3) by the action of phosphine on arsenic halides.8 The properties of these substances resemble in general those which would be possessed by mixtures of the two elements thus, they burn in air to give the mixed oxides, decompose on heating with vaporisation of first phosphorus and then arsenic, and are oxidised by nitric acid. 

The methods commonly used for preparation of disodium dihydrogen hypophosphate depend upon the oxidation of yellow or red phosphorus. Yellow phosphorus may be oxidized by air1 or by copper(II) nitrate.2,3 Red phosphorus may be oxidized by chlorite,4 hypochlorite,5,6 alkaline permanganate,7 hydrogen peroxide,7 or iodine.8 The phosphorus (III) halides, upon hydrolysis and treatment with iodine, yield some hypophosphate.9-11 Electrolytic oxidation of a phosphide of copper, nickel, or silver3 has also been used. 

The crystal chemistry of the phosphide oxides discussed above is closely related to the structural slabs of the well-known BaZn2P2 type (isolated /BaAU type (P2 pairs) and related compounds. This is different for the phosphide halide structures. Some relevant structures of the phosphide halides are presented in Figure 21 and a list is given in Table 9. These structures contain isolated phosphorus atoms, P2 pairs, or one-dimensional spirals like in the structure of elemental selenium. 

Figure 21 Crystal structures of various ternary phosphide halides. Europium (cadmium, mercmy), phosphorus, and halogeu atoms are drawn as large light grey, filled, and open circles, respectively. Some relevant coordination polyhedra aroimd the phosphorus atoms and the P-P bonds are shown. The HgBr4 tetrahedra in the (Hg2P)2HgBr4 strucmre fill the channels of the three-dimensional [Hg2P] network...

Tris(trimethylsilyl)phosphine and its more reactive derivative lithium bis-(trimethylsilyl)phosphide-2tetrahydrofuran are very useful reagents for the preparation of compounds with a single or a multiple element phosphorus bond. They react readily with various element halides, with carboxylic acid chlorides, and with carboxylic esters, as well as with other organic electrophiles via a substitution of lithium and/or a cleavage of the weak polar Si-P bonds. 

Like the red solutions obtained from and NaOR, the red phosphides derived from phosphorus and organometallic reagents were found to react with alkylating agents to give tertiary phosphines s) Addition of butyl chloride to the reaction mixture from phenyllithium and (ratio 2 2 1) in ether gave di-butylphenylphospliine (37%) and butyldiphenylphosphine (44%). Similar products were obtained from the reactions of 4-methoxyphenyllithium, 3-trifluoro-methylphenyllithium or phenylsodium witli phosphorus and butyl halides ... 

In contrast to the liquid ammonia reaction trisodiumphosphide, Na3P, is the major product resulting from the reaction of white phosphorus (red phosphorus, proved less satisfactory) with sodium potassium alloy or with sodium dispersions in inert organic media (e.g. toluene) at temperatures varying from 80 to 145 °C The phosphide Na3P reacts readily with methyl halides in glyme solvents to afford methylphosphorus compounds in ca. 60% overall yields under optimum... 

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