Group 15 elements phosphorus compounds

Supplementary Work, Vol 24 Perfluorohnloorganic Compounds of Mam Group Elements Part 3 Phosphorus, Arsenic, Antirnon and Bismuth Compounds Perfhiorohaloorganic Compounds of Main Group Elements Part 5 Compounds oj Nitrogen (Heteroc clrc Compounds)... 

Organic polymers provide one of the most versatile groups of materials and have widespread uses. Due to some inherent deficiencies, mainly poor heat and flame resistance, these materials suffer from limitations in certain areas of application. The resistance of polymers to high temperatures and flame may be increased by the incorporation of both aromatic rings and certain chemical elements in the polymer chain. It has been found that phosphorus, present either as a constituent in the polymer chain or incorporated as an additive in the form of a phosphorus compound to the polymer system, can make polymers flame retardant [109]. 

The in-V compounds combine the elements of Group HI (aluminum, gallium, indium) with those of Group V (phosphorus, arsenic, antimony, bismuth). As can be imagined, a wide variety of compounds can be produced which, in addition to the binary materials, also include ternary and even quaternary materials. 

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>. 

An area of current development is the nomenclature of organometallic compounds. Organometallic compounds of Main Group elements can, to a first approximation, be considered to be derivatives of hydrides, and the methods of substitutive nomenclature can be applied. Even then, the accessibility of different oxidation states, as with phosphorus(iii) and phosphorus(v), introduces complications. Transition metal organometallic compounds are even more difficult to treat, and the development of a unified, self-consistent and accepted and applied nomenclature is not easy. Witness the different ways (k, t and italicised symbols) for denoting donor atoms in ligands. 

For the lighter elements, which are more basic, protonation/deprotona-tion may take place at the main group element [Eqs. (251) and (252)].235 279 The H atoms attached to phosphorus in Fe3(CO)9 PH 2 and [Fe3(CO)9(PH) (PMe)] are displaced by chloride when the compound is treated with CC14.279... 

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