Alkali metal phosphides

The alkoxide group R is chosen so that the heavier alkali metal alkoxide MOR is soluble in ether or hydrocarbon solvents and so the by-product LiOR may easily be separated from the desired heavier alkali metal phosphide/arsenide (which is often insoluble in weakly or noncoordinating solvents such as ethers and hydrocarbons). 

The first heavier alkali metal phosphide species to be structurally characterized were the sodium and potassium complexes [M P(mes) (SiFBu2) (THF)2]2 (M = Na, K) (67). These isostructural complexes adopt an eight-membered (MPSiF)2 ring motif in which each alkali... 

The heavier alkali metal phosphides M P(SiMe3)2 (M = K, Rb, Cs) have been synthesized by P-Si cleavage of the corresponding trisilyl-phosphine with MOBu1 and have been structurally characterized as their THF adducts [M P(SiMe3)2 (THF)]x (21). The greater size of the... 

Heterometallic alkali metal phosphide complexes with transition metals have also been reported. The complex [(Cy2P)3Hf(ju.-PCy2)2Li (DME)] results from the reaction of LiPCy2 with HfCl4(THF) (98). This complex persists in solution. Jones et al. have reported the synthesis and reactivity toward a range of electrophiles of a series of lithium di-t-butylphosphido(alkyl)cuprates [RCu(PBu2)Li] (R = Me,... 

Alkali-metal phosphides, 19 59 Alkali metals, 14 248 20 597, 598 as anionic initiators, 14 245-248 cation binding of, 24 41 soap and, 22 723... 

The reaction of alkali metal phosphides with appropriate halides, sultones or cyclic sulfates is a generd method for preparation of a variety of tertiary phosphines useful in aqueous organometallic catalysis. These... 

Sultones are useful starting materials for the preparation of various sulfoalkyl- (18, 20) or sulfoarylphosphines (7) when reacted with the appropriate alkali metal phosphide [20]. Reaction of the homologous alkyl-1,2-sultones (C3 to Cu) with tris(2-pyridylphosphine) afforded highly water soluble betains (30) [21]. 

By far the most ubiquitous intermediates in synthesis of this class of phosphines are the alkali metal phosphides which can be prepared by either the KOH/DMSO method, by reaction of tertiary phosphines or chlorophosphines with alkali metals, or in the reaction of BuLi with appropriate secondary or tertiary phosphines. A number of the ligands in Figures 6 and 7 were prepared this way (60-69,72-74). 

The method of greatest applicability is the reaction of alkali metal phosphides with dihalo-alkanes, -alkenes, etc. (equation 4). Generally this reaction proceeds well and in high yield excess dihaloalkane should be avoided as this leads to the production of phosphonium salts which can contaminate the product. 

Reaction with Phosphorus Nucleophiles. The ethyleneimine ring can be opened using phosphines (91) or alkali metal phosphides (92) ... 

Because of the solubility of alkah metals in NH3(1), some alkali metal phosphides have been prepared from NH3(1). Reactions in solvents, either by using compounds containing polyauions or, in the course of suitable syntheses, from compounds starting with isolated phosphorus aitions or from... 

Jnst as the cages Py and Pio are derivatives of the tetrahedral P4 molecule, the Pn cage, characteristic for the M3P11 alkali metal phosphides, is a derivative of the... 

Reactions of alkali-metal phosphides in liq NHj with protonic acids, such as NH,jBr, readily yield phosphine or substituted derivatives ... 

A variety of ammonia solvated alkali metal phosphides has recently been prepared in the Korber group. Examples of these peculiar compounds are Cs2P4-3NH3 with the Gtt aromatic P4 anion and CssPn-SNHs. ... 

The synthesis and uses of alkali metal phosphides have been reviewed. Alkali metal diphenyl-phosphides are readily obtained by cleavage of a phenyl group from PPh, by lithium in tetra-hydrofuran (THF), sodium or lithium in liquid ammonia or potassium in dioxane (equation 3). The metal-phenyl product can be destroyed by addition of a calculated amount of Bu Cl or NH4X. Usually MPPhj compounds are prepared in situ, but they can be isolated, usually as solvates. These compounds can also be obtained from Ph2PCl and the alkali metal, or from Ph2PH and alkyl-lithium. ... 

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