The time required for water attack at the phosphorus atom of simple phosphodiesters and of DNA.

Phosphodiester linkages, including those that join the nucleotides of DNA, are highly resistant to spontaneous hydrolysis. The rate of water attack at the phosphorus atom of phosphodiesters is known only as an upper limit, based on the hydrolysis of the dimethyl phosphate anion. That reaction was found to proceed at least 99% by C-O cleavage, at a rate suggesting an upper limit of 10(-15) s(-1) for P-O cleavage of phosphodiester anions at 25 degrees C.

The rate of hydrolysis of phosphomonoester dianions and the exceptional catalytic proficiencies of protein and inositol phosphatases.

To evaluate the proficiency of phosphatases as catalysts, the rate of the uncatalyzed hydrolysis of simple phosphate monoester dianions was estimated by extrapolating rates measured over a range of high temperatures. The rate of spontaneous hydrolysis of phenyl phosphate dianion indicates that a linear free energy relationship reported earlier is reliable for leaving groups whose conjugate acids have pKa values up to at least 10. Using Teflon reaction vessels, it proved possible to follow the hydrolysis of methyl phosphate and 3-(4-carboxy)-2,2-dimethylpropyl phosphate in strong alkali.