Polyphosphate anions

The sodium salts of these acids, sodium pyrophosphate (Na4 P2 O7) and sodium triphosphate (Nas P3 Oio), have been used widely in detergents. The polyphosphate anions are good additives for cleansing agents because... 

What is the chemical formula of the next largest polyphosphate anion Draw a ball-and-stick model of this anion. 

Physical properties of solid polyphosphate glasses and their melts are also in accord with the conclusions drawn from chemical studies. The X-ray diffraction pattern shows the polyphosphate anions to consist of long chains of P04 tetrahedra (32) and the same conclusion is reached by studying the double refraction of fibers formed by rapidly drawing supercooled melts of Graham s salt (101). 

If the exchange constants for the cations are compared with their catalytic activity (Table XI) and the order of their degrees of dissociation in polyphosphate solutions (Table XII), a considerable measure of correlation will be recognized. It follows that the cations become more active catalytically as they become more strongly bonded to the polyphosphate anions. This also accords with the increase in their effectiveness as the dielectric constant of the solvent is decreased. 

Fig. 16.29 Separation of polyphosphate anions by paper chromatography. The ions are first allowed lo migrate ki a bask solvent and subsequently in an acidic solvent. The straight-chain polyphosphates lie on the ascending branch of the Y." the meuiphosphates on the lower branch. (From Van Wazer. i. R. Phosphorus and Its Comp,ntnds. Wiley New York. 1958 Vol. (. p 702. Reproduced with per mission.J...

A Gel Chromatographic Study on the Interactions of Long-Chain Polyphosphate Anions with Magnesium Ions... 

The diphosphate anion, P2O7 (also known as pyrophosphate), is the simplest polyphosphate anion and is found in many solids. Variations in composition and structure are similar to those described above for the orthophosphates. 

Linking phosphate tetrahedra into chains through two vertices results in polyphosphate anions, also... 

Because of the strong bonds it makes with oxygen, nitrogen and sulphur, phosphorus forms a large number of polymers. Polyphosphate anions have —P—O—P— linkages and so have the oxygen-linked compounds ... 

Attention is directed toward the polyphosphate anions as the structural element under consideration. The cationic functions are considered only as they influence the behavior of the anions. Phase chemistry and thermodynamics become important considerations in devising schemes to control the grow of longer and longer polyphosphate chains. The cationic components of the phase systems cannot be ignored, but they will be relegated to a causal role. 

Metal oxides (and water) are chain growth terminators of long chain polyphosphates as predicted by Equation 1. The long chain polyphosphate chains are very sensitive to chain breakers. The difference between a polyphosphate anion of chain length 1000 and one of chain length 2000 is only one M2O group per two thousand PO3 groups. 

Gupta, K. C. and Jabrail, F. H. Ontrolled-release formulations for hydroxyl urea and rifampicin using polyphosphate-anion-crosslinked chitosan microspheres. J. Appl. Polym. Sci. 104 (2007) 1942-1956. 

Photophosphorylation process discovered First laboratory synthesis of a 3 -5 linked dinucleotide Existence of long-chain polyphosphate anions in the crystalline state confirmed by x-ray analysis Structure of Vitamin eluddated by x-ray diffraction Discovery that phosphorylation is the chief mechanism whereby cells activate or deactivate the enzymes that are present Ribosomes shown to contain RNA Discovery of DNA polymerase Identification of t-RNA Triple helices of DNA first observed... 

Chitosan and some of its derivatives, which are cationic polyelectrolytes, when mixed with alkali polyphosphates (anionic polyelectrolytes) will produce insoluble or gel-like macromolecular complexes. These are reported to be of use in microcapsules and in biotechnology. The structures of these materials are not known, but they presumably involve cross-linking between the chitosan and polyphosphate chains (10.32). 

The absorption of polyphosphate anions is believed to take place primarily on the positively charged edges of the plate-like clay particles, although there is evidence that some absorption on the plate faces may also occur (Figure 12.13b). At the edges of the clay particles, the polyphosphate anions have easier access to the AF+ cations in the clay (Figure 5.55), which are then believed to be complexed. Under acid conditions this AP may be extracted and insoluble aluminium phosphates formed. This happens with phosphoric acid soil stabilisation (Chapter 5.1) and in the setting of some refractory cements (Section 12.10). 

Figure 4.1. Acridenium ions force an alignment of polyphosphate anions to allow them to fit a crystal lattice.

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