Phosphorus rings

Phosphates, nomenclature, 113-115 Phosphinates, nomenclature, 116 Phosphonates, nomenclature, 115-116 Phosphorus, ring oxygen replacement by, 140-141... 

Two approaches have been used in the synthesis of these types of compounds. Small boron-phosphorus ring compounds can serve as building blocks, and addition and elimination reactions with other main group elements can then extend the cage structure (see Schemes 23 and 24, Section 12.12.6.4.5). Alternatively, an unsaturated carbenoid fragment can be added to the bicyclic fragment as illustrated in Scheme 31 <1998IC490>. 

Several books and general reviews are already available on phosphorus ring and cage systems (16). This one will focus more specifically on the coordination chemistry of molecular tetraphos-phorus-based doso-compounds, including itself and closely related analogs, and will also include structural data on both free and coordinated species. The questions of the transmission of electronic and structural effects through the molecular frame, and of the extent oftt-bonding, will be critically considered. 

B. Three-Membered and Five-Membered Nitrogen and Phosphorus Rings. 388... 

A. Specific Features of the Electronic Structure of Nitrogen and Phosphorus Rings Compared with the Corresponding Parent Hydrocarbons... 

Since the aromaticity of hexazine and benzene is of about the same degree, evidently, the instability of the former must be related to some specificities of the cr-system. A detailed analysis of the factors that determine the instability of the nitrogen and phosphorus rings based on the... 

The phosphorus ring member has phosphenium character. It adds tetrachloro or/Ao-quinone and 2,3-butanedione and it also reacts with dimethylaniline and anisole in a pura-substitution... 

By analogy with borazines, the initial interest in the analogous unsaturated boron-phosphorus rings focused on the fundamental issue of the extent of... 

Saturated germanium- and tin-phosphorus rings of the type (R2MPR ) (M = Ge, Sn n = 2,3) have been the subject of a limited number of studies. 

Phosphabicyclo-[2.2.1]heptane and -[2.2.2]octane 1-oxides can be prepared by the reaction of branched tribromides with triethyl phosphite by an Arbusov reaction, followed by a Grignard reaction in the presence of Mg in THF when the carbon-phosphorus rings are closed (equation (11)). When the JH and 13CNMR data were studied certain very large... 

In addition to the +3 oxidation state seen in the homocyclic rings discussed above, phosphorus rings exist in which the +5 oxidation stale is exhibited ... 

A rich and diverse chemistry has developed based on the phosphorus ring system complexed to transition metals analogous to the metallocenes. Phospholes and phosphametallocenes have recent-... 

Phosphorus—phosphorus bonds, addition, to alkynes, 10, 751 Phosphorus rings, chromium carbonyl link arsenic rings, 5, 226 As, Sb, Se, Te, Sn rings, 5, 226 boron rings, 5, 222 carbon rings, 5, 224 characteristics, 5, 221 oxygen rings, 5, 227... 

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