Phosphorus mononitride

The CAAC framework has been used to stabilize group 15 radicals as well as phosphorus mononitride, PN. A first report (2010) [305] describes the preparation of a phosphinyl radical cation by oxidation of a tetramethylpiperidine capped, monoamino phosphaalkene formed from CAAC A (Scheme 15.32). The radical cation was characterized in the solid state using X-ray crystallography and in solution by EPR spectroscopy. The room temperature EPR spectrum consists of a doublet of multiplets with a large hyperfine coupling to phosphorus and a small coupling to one or two nitrogen atoms (g= 2.007 ( P)=99 G ( N) 4 G), typical of phosphinyl radicals. 

The first carbene-stabilized phosphorus mononitride was also synthesized using CAAC A [222], Reaction of SIPr=N-PCl2 with CAAC A, followed by reduction with magnesium metal, afforded the phosphorus mononitride adduct stabilized by one SIPr NHC and one CAAC A (Figure 15.54). This molecule features a P-N distance of 1.7085(16) A as measured by X-ray crystallography. Oxidation using trityl tetrakis(pentafluorophenyl)borate gave the radical cation as a dark-brown-colored microcrystalline solid. EPR spectroscopy in fluorobenzene... 

When Roscoe investigated them he found that vanadium is a tri- and pentavalent element of the phosphorus group. He also discovered that what Berzelius had taken for the metal was really the mononitride, VN, and that most of the vanadium compounds studied by the Swedish chemists had contained oxygen. 

Continuous series of solid solutions are formed between the common highly polymerised forms of adjacent pnictide elements that is, P/As, As/Sb and Sb/Bi. Solid solution formation between the remaining combinations, that is, P/Sb, P/Bi and As/Bi, appears to be very limited and lies below 1% of any one element in the other. Nitrogen does not dissolve to any appreciable extent in either Sb or Bi, although the mononitrides SbN and BiN are reported to exist. Nitrogen does, however, form several phosphorus nitrides (Section 4.5) and arsenic analogues of these exist. 

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