Phosphoric acid, pyro

Fig. 5. Vapoi—liquid phase diagram of the H2O—P20 system at 101 kPa (1 atm), where 3 is ortho, 2 pyro, and 1 meta phosphoric acid. The soHd line...

When AMP is heated under reflux in DMF, the 2, 3 -cyclic phosphate is formed, and cyclic phosphates can also be obtained from nucleosides and ortho-, pyro-, or poly-phosphoric acids under the same conditions. Promotion of phosphorylation by DMF is well known and the reaction with AMP is probably intermolecular as no 3, 5 -cyclic AMP can be detected. Minor products in the latter reaction are the 2, 3 -cyclic 5 -diphosphate and the 2 (30,5 -diphosphate. The synthesis of adenosine 2 (3 )-phosphate 5 -pyrophosphate has been achieved by the phosphoromorpholidate method used in a synthesis of Co A. ... 

PE layers were formed in Z-cut LiNbOs and LiTaOs congruent crystals by using a variety of proton sources, such as benzoic acid - pure (CeHsCOOH) or diluted with lithium benzoate (CeHeCOOLi) pyro-phosphoric acid (H4P2O7), etc. The plates were immersed in the acid melt for various periods of time (up to 8 h in the case of LiNbOs and up to 42 h for LiTaOs substrates) at a temperature in the range of 200 - 240°C. Some of the samples were subsequently annealed at temperatures up to 420°C for periods of time varying from 10 min to 2 h. 

Also, phosphoric acid forms an extensive series of anhydrides (with P—O—P bonds), which further diversify the number and kind of phosphate esters. The most important phosphate esters are derivatives of mono-, di-, and triphosphoric acid (sometimes classified as ortho-, pyro-, and meta-phos-... 

The chemistry of the amido- and imido-diphosphoric acids is not in a satisfactory state. The interpretation of the experimental work by different investigators is discordant, showing a lack of precise facts. The reports of the preparation and properties of the three amidophosphoric acids indicated above are largely based upon the work of J. H. Gladstone and J. D. Holmes.1 A. Mente s and H. N. Stokes re-survey of the field outlined by J. H. Gladstone and J. D. Holmes shows that the interpretation of the results was probably erroneous in other words, the amido-diphosphoric acids reported by J. H. Gladstone and J. D. Holmes may really be imido-diphosphoric acids, or mixtures of the same with meta- and pyro-phosphoric acids. A number of amidopyrophosphoric acids have been... 

Fio. 46.—Vapour Pressures of Pyro- and Meta-phosphoric Acids. 

A. B. Poggiale 24 reported that dil. soln. of ortho-, pyro-, or meta-phosphoric acid are not poisonous, while cone. soln. behave like other strong acids. N. Sieber... 

Di- or pyro-phosphoric acid (m = 2) Triphosphoric acid (m=3) Tetraphosphorie acid (m — 4). ... 

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