Activation of white phosphorus

Figure 15.20 Structure of the carbene-P4-borane adduct generated from FLP activation of white phosphorus [99],...

Stephens, F.H., 2004. Activation of white phosphorus by molybdenum- and uranium tris-amides. 

Seidel WW, Summerscales OT, Patrick BO et al (2009) Activation of white phosphorus by reduction in the presence of a zirconium diamidodiphosphine macrocycle formation of a bridging square-planar cyclo-P4 unit. Angew Chem Int Ed 48 115-117... 

Pour a small amount of copper sulphate, silver nitrate, and potassium manganate solutions into three beakers and drop a small piece of white phosphorus into each of them. In 10 or 15 minutes, extract the phosphorus from the solutions. Dry it as indicated above, put it on an iron plate, and heat it. What happens How do the given salts affect white phosphorus How can the different activity of white and red phosphorus be explained Write the equations of [the [reactions. 

Compare the reaction of white phosphorus and the reaction of sulfur in the Reactions with Oxygen movie eChapter 14.8). Which of these two reactions do you think has the higher activation energy For each reaction, sketch an energy profile similar to the one in Figure 12.14 (page 500). 

Studies reporting acute oral exposure of humans to white phosphorus were limited to case reports of intentional or accidental ingestion of match heads, rat poison, cockroach poison, firecrackers, or from military operations. Manufacturers of white phosphorus-containing rat poison have claimed that the only active ingredient in the rat poison was... 

All operations with phosphorus and reactive phosphides should be done in a hood or dry box and equipment should be on hand to deal with the possibility of a phosphorus fire. Phosphides may ignite if milled mechanically under ambient conditions and even highly purified red phosphorus may contain small inclusions of white phosphorus. Therefore, all grinding should be done under an inert atmosphere. On contact with wet air or wet inert gas, phosphides may produce phosphines (odor, selfignitability). Phosphines have also been shown to be physiologically active. ... 

A critical survey of the coordination chemistry of white phosphorus illustrating the metal-mediated degradation of the P4 tetrahedron is presented. The underlying principles to account for the activation and stepwise fragmentation of this molecule in the presence of transition metal complexes are presented with emphasis given to mechanistic aspects. A collection of 31P-NMR spectral data for the known poly phosphor us Px compounds (x < 4) is also presented and briefly commented. 

An intriguing example of P4 activation, en route to the separation into two diphosphorus units, has been recognized in the complex [Fe6(CO)20(/i3, 1 1 1-P4)] (63), which is straightforwardly generated from the thermal reaction of white phosphorus and [Fe2(CO)9] in boiling benzene (Eq. 9) [79] ... 

In the case of white phosphorus, the reaction proceeds through the following elementary steps (i) ethane elimination, (ii) P-P bond activation at iridium forming the Ir(m) hydride [(triphos)IrH(77 -P4)] 921, (iii) isomerization of 921 to [(triphos)Ir( j -P4H)] 922 with selective delivery of the hydride atom to one of the coordinated P-atoms, and (iv) hydrogenation of the teraphosphidohydride ligand with PH3 generation and formation of the known cyclo-Vj, complex [(triphos)Ir( -P3)] 923. 

Recently an example of white phosphorus activation by complexes containing diamidodiphosphine macrocycle 63 was found. A new dinuclear zirconium complex 71 that has a bridging intact planar square P4 unit was obtained in the reduction of 65 using white phosphorus as an additional ligand (Scheme 12.27) [82]. 

Chlorine has caused numerous accidents with metals. Beryllium becomes incandescent if it is heated in the presence of chlorine. Sodium, aluminium, aluminium/titanium alloy, magnesium (especially if water traces are present) combust in contact with chlorine, if they are in the form of powder. There was an explosion reported with molten aluminium and liquid chlorine. The same is true for boron (when it is heated to 400°C), active carbon and silicon. With white phosphorus there is a detonation even at -34°C (liquid chlorine). 

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