Catalytic hydrolysis of phosphate triesters by lanthanide(III) cryptate (2.2.1) complexes

Abstract

Lanthanide(III) cryptate (2.2.1) chlorides [Ln(2.2.1)Cl₃; Ln = La, Ce, Eu] are effective in catalysing the hydrolysis of 4-nitrophenyl diphenyl phosphate. Kinetic studies reveal that the europium(III)(2.2.1) chloride catalyses the hydrolysis efficiently (k= 1.8 × 10^–2 s^–1 at 1.6 mmol dm^–3, turnover number = 12 at pH 9.00 and 25 °C). The reactivity of the cerium(III) complex is enhanced by the presence of molecular oxygen. Analysis of the products of the hydrolysis shows that the selectivity toward yielding 4-nitrophenol against phenol is unusually high (ratio = 17 : 1).