Black phosphorus

Black phosphorus Black powder Black reactive dyes Black Rubber 3773... 

Phosphorous acid, 372 Phosphorus black, 365 boiling point, 374 chemistry of, 368 compounds, 102 heat of vaporization, 374 ionization energy, 268 melting point, 374 occurrence, 373 oxyacids, 371, 372 preparation, 374, 376 properties, 101 structure, 366 white, 120, 365, 366, 369 Photon, 254... 

Reactivity of white phosphorus is much greater than red or black phosphorus. Black phosphorus is the least reactive of all phosphorus allotropes. 

Ores of phosphorus apatite, hydroxy-apatite, iricalcium phosphate (phosphate rock). White phosphorus, red phosphorus, black phosphorus. High polymers and their properties. Manufacture and uses of phosphorus. Ordinary matches, safety matches. 

Two more stable phosphorus allotropes are red and black phosphorus. Small amounts of these are are also produced for special purposes from the white phosphorus product of the electric arc furnace. Red phosphorus is obtained by heating white phosphorus at 400°C for several hours, which yields a complex polymeric material, more dense (2.20 g/cm ) and considerably more stable than the white variety. Red phosphorus is not only stable in air, but far less toxic than white phosphorus. Black phosphorus is more dense again (2.25-2.69g/cm ), and has a different more complex structure. It is obtained by heating the white variety at 220 to 370°C for 8 days plus requires either a pressure exceeding 10 kg/cm or a seed crystal of black phosphorus. This product has a structure resembling graphite, is a good electrical conductor, and can be lit with a match only with difficulty [10] (Table 10.3). 

In the introduction we defined exotic as beautiful, exceptional, weird, paradoxical, and counterintuitive. We also indicated that such species could represent fragile and rare as well as simple and well-characterized classic inorganic compounds. In this section we will look at two of the simplest inorganic classes of compounds polyphosphorus and polynitrogen species. We will dwell on the following elementary question Why is it that polyphosphorus allotropes of the element are well known (white phosphorus black phosphorus in its orthorhombic, rhom-bohedral, and cubic forms red, amorphous phosphorus). 

The remaining forms of elemental phosphoms, namely black and red phosphorus, are insoluble polymers that are much less reactive than white phosphorus. Black orthorhombic phosphorus is the most thermodynamically stable form of this element and can be obtained by heating white phosphorus under pressure. Red phosphorus, in contrast to the black allotrope, is not crystalline but amor-... 

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