Phosphorus compounds, phosphides

The most direct synthesis is performed by reaction of a dihalo compound with a tricoordinated phosphorus compound including a reactive P—Y bond (reaction 101). This synthesis, first used with secondary phosphines, the corresponding phosphides or diphosphines (Y = H, Na, K, PPh2)2b,38°, has subsequently been developed also with silylphosphines (Y = SiMe3),132,381-383 which are easier to handle (reaction 102). The same kind of cyclization by intramolecular alkylation can be achieved using a functional phosphine prepared in a multi-step synthesis380,384,385 (reaction 103). 

Fumigants - [cross-reference entry] (Vol 12) -as food additives [FOOD ADDITIVES] (Vol 11) -phosphides as [PHOSPHORUS COMPOUNDS] (Vol 18)... 

Reaction of Cp LnCl with LiPRR yielded [57] Cp2Ln PR3. When lithium cyclohexyl phosphide is used [Cp7YbPhC6Hn] is formed and [Cp2YbPHPh] is obtained with lithium phenylphosphide. These products are not stable in solution and decompose to yield polymeric compounds [CpYbPCgHi 1 ] and [CpYbPPh],. The compound [Cp2Lu(PPh)2Li(tmed) l/2toluene] has been characterized by X-ray analysis [100] with Lu-P distances of 2.782(1) A and 2.813(2) A. The arsenic compound analogous to the phosphorus compound has the same structure [101]. 

One method for the synthesis of cyclic silicon-phosphorus compounds is the reaction of alkaliphosphides with dichlorosilanes [1]. Using sodium/potassium phosphide, -arsenide, -antimonide and -bismutide Na3E/K3E (E = P, As, Sb and Bi) [2] with various di-, tri-, and tetrachloroorganosilanes, cages of the following types (Fig 1.) have been synthesized so far. 

The chemistry of boron-phosphorus compouuds has been reviewed. Numerous boron-phosphorus derivatives have been reported, but relatively few boron-arsenic or boron-antimony compounds have been described. Boron-phosphorus compounds are similar in many ways to boron nitrogen derivatives, but the teudeucy to share boudiug electrons in covalent tetrahedral compounds is much more evident with phosphorus thau with uitrogeu. lu fact, most boron phosphorus chemistry iuvolves tetrahedral borou. They are typically either phosphiue-boraue complexes, such as R3P BR j, or phosphinoboranes (R2PBR2) , cyclic or polymeric derivatives of the hypothetical H3P BH3. The chemistry of these compounds and that of boron phosphate and thiophosphate is described below. Boron phosphides are discussed in Section 2.6. 

It is important to note that is the maximrun oxidation state in binary phosphides (cf Th3P4, Th2Pn, ThP7) and higher oxidation states are stabilized only by the formation of complexes (see Section 6.2). An exception may be UP2 with the PbCl2-type structure, but the P-P distances (269 pm) indicate an oxidation state (U) < 6. Phosphorus compounds of group 15-17 elements are not covered here PSb, PBi, and PTe do not exist, while other compounds such as PAs (Section 7) are not termed phosphides. 

Use Manufacture of phosphoric acid and other phosphorus compounds, phosphor bronzes, metallic phosphides, additive to semiconductors, electroluminescent coatings, safety matches, fertilizers. Black phosphorus... 

Although the commercial manufacture of the element phosphorus did not develop until the 183O s and by 1844 the total phosphorus production in Great Britain was estimated at only 0.75 tons per year already in 1845 Thenard synthesized the first organophosphorus compounds by the interaction of calcium phosphide (or phosphorus and calcium) and methyl chloride. Today elemental phosphorus is readily and cheaply available. Its high reactivity makes it an excellent starting material for the synthesis of organic phosphorus compounds. 

Compounds consisting of two elements, or of an element and a radical only, binary compounds, are designated by compound names made up of the name of the more electro-positive, followed by that of the more electro-negative, in which the termination ide has been substituted for tbe terminations ine. on, ogen, ygm, orus, turn, and ur. For example the compound of potassium and chlorine is called potassium chloride, that of potassium and oxygen, potassium oxide, that of potassium and phosphorus, potassium phosphide. 

X.2 Phosphorus compounds and complexes X.2.1 Solid and gaseous thorium phosphides... 

In the area of trivalent phosphorus acid chemistry some very unusual reactions have been reported from combinations of 4-dimethylamino-pyridine (DMAP) with phosphorus trichloride. In one case a phosphide and free chlorine are claimed to be formed The extreme nucleofugicity of a tervalent phosphorus atom bearing two DMAP groups also stimulates an unprecedented Arbusov reaction of a tervalent derivative. Another surprise is that, although the reaction is certainly acid-catalysed, the mechanism of substitution at phosphoramidites does not involve either P- or N-protonated species. A final surprise in this area is the preparation, by Russian chemists, of some tervalent phosphorus compounds which apparently contain P-OH groups. 

The debromination of activated v/c-dibromides by trivalent phosphorus compounds has been demonstrated. The process is an E2 type (38, 39). The more potent dicyclohexylphosphide anion is capable of debrominating 1,2-dibromoethane (40). It is of interest to note that the slightly harder diphenyl-phosphide elects to attack on the carbon atom (Sn2). 

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