Phosphorus-nitrogen ring system

A book has been published covering the subject of sulphur-phosphorus-nitrogen ring systems. The chemistry of some specific examples of these rings, NPCla(NSOCl)a and (NPCla)aNSOCl, has been reviewed in detail. ... 

Examples of cyclophosphazenes with ring systems containing elements other than phosphorus or nitrogen continue to be reported. The linear phosphazene [Ph2(H2N)Pi N.i P(NH2)Ph2]+Cl is cyclized by antimony pentachloride to give the compound (35). This result contrasts with... 

The best known boron-containing ring systems are the so-called inorganic benzenes, namely, borazine (71), boroxine (72), and triphosphatriborin (73) (Fig. 46), which are isoelectronic and isostructural with benzene. These ring systems are obtained by the interaction of boron with nitrogen, oxygen, and phosphorus, respectively.4... 

This chapter provides an update of Chapter 8.33 in CHEC-II(1996) <1996CHEC-II(8)863>. The work carried out on the bicyclic ring systems with ring junction P, As, Sb, or Bi has focused primarily on phosphorus. Very little work has been done on the other heteroatoms and as such the synthesis and reactivity of these compounds have been reviewed as one section, Section 12.12.7. Most of the compounds in this class contain more than one heteroatom, the additional atoms usually being oxygen and nitrogen. 

The study of [4.4.0] ring systems has resulted primarily from the study of various other aspects of phosphorus chemistry. An investigation into the effect of nitrogen donor action on the increase in coordination at phosphorus in a series of oxyphosphoranes led Holmes and co-workers <1998IC4945> to compounds 24 and 25. The compounds were fully characterized by NMR spectroscopy and X-ray diffraction. Compound 24 was heated for 30 min at 140°C in an NMR tube. The reaction was followed by 31P NMR spectroscopy which indicated that conversion to a phosphorane 26 and a small amount of phosphate had taken place (Equation 4). The pentaoxyphosphorane 25 was successfully produced via an oxidative addition reaction between the diol 27 and triphenyl phosphate in the presence... 

The [5,5]-fused bicyclic ring system with one fusion nitrogen atom and three additional heteroatoms in a 2 1 distribution over both ffve-membered rings (2N1) is the origin of a great number of structures. The additional heteroatoms are mainly nitrogen, oxygen, or sulfur, and less commonly phosphorus or silicon atoms. 

The combination of the monomer units R2PN and NS provides many possibilities for inorganic ring systems containing phosphorus, nitrogen, and two coordinate sulfur. Thus one might an-... 

Similarly the combination of R2PN and NSCl units affords heterocycles containing phosphorus, nitrogen and three coordinate sulfur (e.g. and 5) which may be considered as hybrids of the well known ring systems (R2PN)3 and (NSC1)3. 

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