THE [CU([9]ANEN(3))(OH)(OH2)](-HYDROLYSIS OF THE PHOSPHOTRIESTER 2,4-DINITROPHENYL DIETHYL PHOSPHATE ([9]ANEN(3)=1,4,7-TRIAZACYCLONONANE)()CATALYZED)

The hydrolysis of the phosphotriester 2,4-dinitrophenyl diethyl phosph ate to diethyl phosphate is catalysed by the macrocyclic complex [Cu([ 9]aneN(3))(OH2)](2+) ([9]aneN(3) = 1,4,7-triazacyclononane). The pH de pendence of the hydrolysis over the pH range 6.2 to 8.7 establishes th at the active catalyst is the hydroxoaqua complex. The pK for the equi librium [Cu([9]aneN(3))(OH2)(2)](2+) reversible arrow [Cu([9]aneN(3))( OH)(OH2)](+) + H+ determined by potentiometric titration is 7.5 at 35 degrees C and I = 0.1 mol dm(-3) so that catalysis at pH values close to neutrality is observed. Hydrolysis occurs by intramolecular attack of coordinated hydroxide on the phosphate triester which is bonded via the phosphoryl oxygen to the copper centre. (C) 1998 Elsevier Science Ltd. All rights reserved.