Phosphine chemical reactions

Complexes 79 show several types of chemical reactions (87CCR229). Nucleophilic addition may proceed at the C2 and S atoms. In excess potassium cyanide, 79 (R = R = R" = R = H) forms mainly the allyl sulfide complex 82 (R = H, Nu = CN) (84JA2901). The reaction of sodium methylate, phenyl-, and 2-thienyllithium with 79 (R = R = r" = R = H) follows the same route. The fragment consisting of three coplanar carbon atoms is described as the allyl system over which the Tr-electron density is delocalized. The sulfur atom may participate in delocalization to some extent. Complex 82 (R = H, Nu = CN) may be proto-nated by hydrochloric acid to yield the product where the 2-cyanothiophene has been converted into 2,3-dihydro-2-cyanothiophene. The initial thiophene complex 79 (R = R = r" = R = H) reacts reversibly with tri-n-butylphosphine followed by the formation of 82 [R = H, Nu = P(n-Bu)3]. Less basic phosphines, such as methyldiphenylphosphine, add with much greater difficulty. The reaction of 79 (r2 = r3 = r4 = r5 = h) with the hydride anion [BH4, HFe(CO)4, HW(CO)J] followed by the formation of 82 (R = Nu, H) has also been studied in detail. When the hydride anion originates from HFe(CO)4, the process is complicated by the formation of side products 83 and 84. The 2-methylthiophene complex 79... 

Irradiation of the phosphine (1) causes a molecular rearrangement, and it was proposed that the primary chemical reaction is C—P bond cleavage.5... 

Phosphine can be analyzed by GC using a NPD detector in phosphorus mode or by GC/MS. The mass ion for its identification is 34. It can be identified also from its odor and formation of smoke ring and other chemical reactions (see Reactions). 

The basicities of phosphines in the liquid phase are dominated by solvation effects in ionizing solvents and the results of measurements shown in Table 13 are clearly the result of gross energy changes of chemical reactions, including solvation energies, whereas those in Table 14 are unencum-... 

W. Ipatieff and W. Nikolaieff observed the formation of phosphine when white phosphorus is heated with hydrogen in a sealed tube at 360° and when water-gas at 400 atm. press, acts on lead phosphate. J. Brossler said that if white phosphorus be added to a mixture of zinc and dil. sulphuric acid, in a short time, spontaneously inflammable phosphine will be produced and if a cone. soln. of alkali hydroxide and zinc be mixed with yellow phosphorus, the spontaneously inflammable gas will be given off at about 60° if the temp, be below 20°, the gas evolved is not spontaneously inflammable. H. Davy, and L. Dusart showed that the gas obtained by the action of zinc and dil. acids on yellow phosphorus contains phosphine, although J. B. A. Dumas questioned the fact. D. Vitali observed that the presence of mercuric chloride retards the formation of phosphine. J. Brossler obtained phosphine by the action of hydrochloric acid and a few drops of nitric acid on tin in the presence of yellow phosphorus. The formation of phosphine during the action of ammonia, and of water on yellow phosphorus has been indicated in connection with the chemical reactions of phosphorus. 

Chemical Reactions.—Phosphonium iodide is hydrolysed by water, and is still more rapidly decomposed by alkalies, giving phosphine and an iodide. The phosphine is displaced by ammonia giving ammonium iodide,8 and even by ethyl alcohol giving ethyl iodide, with phosphine in both cases.9 It is hardly affected by aqueous acids, except those which are also oxidising agents. 

Chemical Reactions.—P12H6 is dissociated when heated above 70° C-. in an indifferent gas—into its elements at 175° C. in CO 1 or into phosphorus and phosphine at 215° C. The ignition temperature in air is 120° to 150° C.1 The only liquids which dissolve it without decomposition are phosphorus and PaH4. It dissolves in ammonia at -40° C. with evolution of phosphine. After evaporation of the ammonia a black solid is left which appears to be an ammine of a higher hydrogen phosphide. Like the other phosphides it is easily oxidised by halogens, chlorates and nitric acid.2... 

Since, in the main, complexes of this type are themselves derivatives of other rhodium complexes there seem to have been few investigations of their chemical reactions apart from the metathetical reactions outlined above. Apart from spectral studies there has been little interest shown in their physical properties, although it may be noted that the emission observed from [RhCl2 ((Ph2Z)2C2H4 2]Cl (Z = P, As) complexes has been attributed to metal-localized phosphorescence.1 43 The ditertiary phosphine complexes are listed in Table 81. 

SAFETY PROFILE Phosphides are particularly dangerous because they tend to decompose to the very toxic phosphine upon contact with moisture or acids. Dangerous fire hazard by chemical reaction, particularly with moisture. Moderate explosion hazard. They react with water, steam, acid, or acid fiimes to produce toxic and flammable phosphine gas. Can react vigorously with oxidizing materials. Dangerous when heated to decomposition they may emit highly toxic fumes of POx. 

Although it is stable at normal temperature and pressure, the substance is classified as highly flammable and may explode when exposed to heat or by chemical reaction with oxidizers. RP can also react with reducing materials and represents a moderate explosion hazard by chemical reaction or on contact with organic materials. It reacts with oxygen and water vapor to produce the toxic phosphine. 

In this context, a functionalized ionic liquid, 1-(2-hydroxyethyl)-3-methyl imidazolium tetrafluoroborate [hemim][BF4], is reported as an efficient and recyclable reaction medium for the palladium catalyzed Heck reaction. The olefination of iodoarenes and bromoarenes with olefins generates the corresponding products in good to excellent yields under phosphine-ffee reaction conditions. After separation of the product, fresh starting materials are charged into the recovered ionic liquid which entraps the palladium catalyst. The reactions still proceed quantitatively for six cycles, without significant loss of catalytic activity. " The effect of both the cation and the anion on the chemical yield is shown in Figure 28. 

Part of our research program in phosphorus chemistry deals with the study of new chemical reactions of two such low-coordinate phosphines the (methylene)phosphine (2), (Me3Si)2NP=CHSiMe3 (1) and the iminophosphine... 

At 650°C, phosphine vapor decomposes according to the first-order, chemical reaction... 

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