Kinetic and Equilibrium Studies of the Copper(II) Promoted Hydrolysis of Salicyl Phosphate. A Rate Acceleration of 1E8 for the Hydrolysis of a Phosphate Monoester Dianion
The dissociation constants of salicyl phosphate (H3L) at 10 deg C and I= 0.1 mol dm-3 have been determined (pKa values 1.84, 3.57, and 6.18).At a 1:1 ligand to metal ratio the interaction of copper(II) with salicyl phosphate can be described by the equilibria given below. The pKa values for the ionisation processes CuHL - + H+ and - 2- + H+ are 5.1 and 5.9 respectively.Kinetic studies establish that in the copper(II) promoted hydrolysis, the complex - is the active species with kCuL- = 6 * 1E-4 s-1 at 25 deg C and I = 0.1 mol dm-3.Copper(II) ions promote the hydrolysis of the dianion of the phosphate monoester by a factor of ca. 1E8.Previous work in this area had indicated only a small rate acceleration (ca. 10 fold) as comparisons were made between the metal-ion promoted reaction and the intramolecular general acid catalysed hydrolysis of the phosphate monoester dianion.
Hay, Robert W.,Basak, Arup K.,Pujari, Mahesh P.,Perotti, Angelo
p. 2029 - 2034
(2007/10/02)
More Articles about upstream products of 87655-41-2