Phosphorus nitride

Phosphenyl Chloride Phosphides Phosphorus nitride. Oxyhalides. 

The main products from the reaction between phosphine and atomic nitrogen are molecular hydrogen and phosphorus nitride (PN), which is formed in the a form For the conversion of one mole of phosphine into (PN), two atoms of nitrogen appear to be necessary. The primary step is the formation of PH2 radicals which react further with the nitrogen atoms to give the nitride... 

The phosphorus nitride of the early workers—H. Rose,11 and F. Wohler and J. von Liebig—was probably phosphorus imidonitride, PN2H, or N j P NH, sometimes called phospham. It was made by F. Wohler and J. von Liebig, C. Gerhardt, and H. Davy by heating phosphorus pentachloride in ammonia and by H. Rose, by the action of ammonia on phosphorus pentachloride, trichloride, or tribromide ... 

These three ammonium salts, and the free acid, when heated may pass into thio-phosphoryl nitrile, and at a red-heat into phosphorus nitride. When diammonium nitrilodithiophosphate is heated, it loses ammonia, forming the monammonium salt —the free acid, nitrilodithiophosphoric acid, N P(SH)2, has not been made ... 

Ceramic-type materials that contain no organic linkage units can be prepared by the pyrolysis of cyclic or high polymeric aminophosphazenes. An example is shown in reaction (44). Under appropriate conditions, pyrolysis products that correspond to phosphorus-nitride are formed. Polyphosphazenes that contain both amino and borazine side groups yield phosphorus-nitrogen-boron ceramics following pyrolysis 94,95 The conversion of a formable polymer into a ceramic has many potential advantages for the controlled synthesis and fabrication of advanced ceramics. This principle is discussed in more detail in Chapter 9. 

In the following sections some examples are given of the ways in which these principles have been utilized. The first example is the use of these techniques for the low temperature preparation of oxide ceramics such as silica. This process can also be used to produce alumina, titanium oxide, or other metal oxides. The second example describes the conversion of organic polymers to carbon fiber, a process that was probably the inspiration for the later development of routes to a range of non-oxide ceramics. Following this are brief reviews of processes that lead to the formation of silicon carbide, silicon nitride, boron nitride, and aluminum nitride, plus an introduction to the synthesis of other ceramics such as phosphorus nitride, nitrogen-phosphorus-boron materials, and an example of a transition metal-containing ceramic material. 

A related synthetic strategy by Allcock and Welker65 is illustrated in reaction (19). Here, borazine side groups are linked to a polyphosphazene chain. This reduces the volatility of the borazine and allows facile fabrication of the linear high polymer. Subsequent pyrolysis at temperatures up to 1,000 °C results in breakdown of the phos-phazene carrier backbone (possibly via the formation of volatile phosphorus nitride) and formation of boron nitride. 

It is also known that cyclic trimeric aminophosphazenes undergo similar reactions when heated to give linked ring systems called phospham . Presumably this is another potential intermediate en route to phosphorus nitride. 

Amido-derivatives of Phosphorous and Orthopbosphoric Acids—Amido- and Imido-derivatives of Metaphosphoric Acid.—Amides and Imides of Condensed Phosphoric Acids—Nitrilophosphoric Acids—Amido-, Imido- and Nitrilo-thiophosphoric Acids—Phosphorus Halonitrides or Amidohalides— Phosphorus Nitride. 

In another recent study, amorphous phosphorus nitride imide (HPN2), a ternary inorganic polymer, has also been prepared via a benzene-thermal reaction of PCI5 and NaN3 under mild conditions [40], The products have interesting morphologies (Fig. 10) of microtubes, hollow balls and square frameworks. Their potential use for industrial application is now under investigation. 

The phosphorus nitride radical PN, isoelectronic with SiO, has recently been detected in interstellar space. It is readily prepared in high-temperature vapors either by heating solid P3N5 to HOOK or by dehalogenation of cyclic (NPCl2)3 with Ag ... 

N5P3 (s) Phosphorus Nitride P3N5 (s) N5P3 (s) P3N5 (S)... 

Phosphorus nitride (p3Ng) NsPgCcr) 1564 Potassiim chloride ((KCUg) Cl2K2(g) 808... 

In the last few years we began our efforts to develop new inorganic solid materials with the synthesis and structure determination of the phosphorus nitrides [2]. Based on the synthesis of pure, defined, and crystalline P3N5 [3] we started a systematic preparative and structural investigation of ternary and multinary phosphorus nitrides. 

Fig. 1. In phosphorus nitrides PN4 tetrahedra occur as typical building blocks, which may be linked via common vertices exhibiting structural analogies to silicates and phosphates.

Analogous to the formation of ternary oxosilicates by reaction of an alkaline metal oxide with an acidic nonmetal oxide the synthesis of a ternary phosphorus nitride is possible (Scheme 1). 

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