Boron-phosphorus polymers/chain

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. 

The five membered cydic 1,3-dioxolane (CHjOCHjCHjO) can be polymerised by a variety of catalysts including sulphuric acid (P7), perchloric acid (98), phosphorus pentachloride (PP) and alkyl aluminium compounds with water as a co-catalyst (100). The effect of the catalyst boron trifluoride diethyl etherate on the polymerisation of 1,3-dioxolane has also been studied and it has been found that equilibrium between monomeric 1,3-dioxolane and poly(l, 3-dioxolane) is set up in both the undiluted polymer and in solution (101-104). Controverf has arisen as to whether the equilibrium is between cyclic monomer and cyclic polymer (98) or between cyclic monomer and chain polymer (104). 

Inorganic polymers have backbone chains that do not contain carbon, as organic polymers do, but atoms such as oxygen, nitrogen, phosphorus, boron, silicon, and metals or alternating combinations of them. The side groups attached... 

Polyphosphinoboranes containing phosphorus and boron linked to each other in polymeric chains have remained elusive for a long time. Recently, catalytic dehydrogenation of the phosphine-borane adducts has been found to be effective to prepare the linear polymer. Thus, thermal treatment of PhPH2.BH3 in the presence of catalytic amounts of [(l,5-COD)Rh( j,-Cl)] affords the linear polymer poly(phenylphosphinoborane), [PhHPBH2]n (see Eq. 1.13) [28-30]. High polymers with of about 33,000 have been isolated by this procedure. 

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