Diphosphoric acid, structure

A feature of phosphoric acid is that it forms a series of poiymeric anhydrides that resembie carboxyiic acid anhydrides in structure and reactivity. Diphosphoric acid (formeriy caiied pyrophosphoric... 

Certain inorganic and simple carbon-containing compounds are commonly given non-systematic or semi-systematic names containing the word acid . Examples are boric acid or orthoboric acid, metaboric acid, phosphoric acid, diphosphoric acid, cyc/o-triphosphoric acid, cafena-triphosphoric acid, dithionous acid, peroxodisulfuric acid or peroxydisulfuric acid, etc. These names are unique in modern nomenclature in that, interpreted literally, they describe a particular chemical property of the compounds in question. Systematic names are otherwise based solely on composition and structure. 

Dolichols are a family of long-chain polyisoprenols that occur only in eukaryotes. They are related in structure and function to undecaprenyl phosphate, a prokaryotic polyisoprenol used in the synthesis of peptido-glycan (see below). Dolichols contain 65-110 carbons arranged as 13-22 isoprene units, two in the trans configuration, the remainder in the cis configuration. The initial isoprene unit is saturated and carries a hydroxyl group, which is esterified with orthophosphoric (monophosphoric) or pyrophosphoric (diphosphoric) acid in dolichol phosphate and pyrophosphate, respectively (Figure 16-6). 

X-Ray structures have been completed for the caged carbophosphorane (95) and the cyclohexylammonium salt of the di-/3-naphthyl ester of diphosphoric acid. The latter is a model compound for conformational studies on physiologically active diphosphates where hydrogen-bonding is probably important. The... 

Diphosphates. Changes in the configurational entropy for the anhydrous sodium diphosphates have been calculated from observed crystal structures,and factors such as water content of the atmosphere influencing the formation of a- or jS-Na2H2P207 from NaH2P04 by thermolysis have been elucidated.The interaction between and diphosphoric acid in water and D2O has been... 

Chemical name Sodium pyrophosphate-10H2O (PYP) Tin(ll) diphosphate Technetium tin pyrophosphate injection (Ph. Eur.) Technetium Tc 99m (pyrophosphate injection (USP) 99nfiTc-(Sn)-pyrophosphate injection 99mTc-PYP Chemical structure 0 0 II II HO—P—0 — P—OH 1 1 HO OH Diphosphoric acid ... 

When H3PO4 is heated at 510K, it is dehydrated to diphosphoric acid (equation 14.128). Comparison of the structures of these acids (Table 14.7) shows that water is ehminated with concomitant P—O—P bridge formation. Further heating yields triphosphoric acid (equation 14.129). 

The adenine nucleotide system consists of the following members adenosine 5 -phosphoric acid (AMP), adenosine diphosphoric acid (ADP), and adenosine triphosphoric acid (ATP). The structures of these compounds are given in Fig. 5. These structures have been confirmed by the classical chemical synthesis of Todd and his co-workers. ... 

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