Catalytic activities of Schiff base aquocomplexes of copper(II) towards hydrolysis of amino acid esters

Summary Solid aquo Cu^II complexes of Schiff bases derived from amino acids have been prepared and characterized. Using a pH-stat method, the kinetics of base hydrolysis of the amino acid esters H₂NCH₂CO₂Me·HCl (GE), (HO)-C₆H₄CH₂(NH₂)CO₂Me·HCl (TE), MeS(CH₂)₂CH(NH₂)-CO₂Me·HCl (ME), HSCH₂CH(NH₂)CO₂Et·HCl (CE), C₃H₃N₂CH₂CH(NH₂)CO₂Me·2HCl (HE) and —SCH₂-CH(NH₂)CO₂Me]₂·2HCl (CysE) have been studied. The complexes enhanced the rate of hydrolysis substantially, the values of the second-order rate constants being some 10–50 times greater than those obtained in the presence of the simple Cu^II ion.