New La(III) Complex Immobilized on 3‑Aminopropyl-Functionalized Silica as an Efficient and Reusable Catalyst for Hydrolysis of Phosphate Ester Bonds

Described herein is the synthesis, structure, and monoesterase and diesterase activities of a new mononuclear [La^III(L¹)­(NO₃)₂] (<b>1</b>) complex (H₂L¹ = 2-bis­[{(2-pyridylmethyl)-aminomethyl}-6-[<i>N</i>-(2-pyridylmethyl) aminomethyl)])-4-methyl-6-formylphenol) in the hydrolysis of 2,4-bis­(dinitrophenyl)­phosphate (2,4-BDNPP). When covalently linked to 3-aminopropyl-functionalized silica, <b>1</b> undergoes disproportionation to form a dinuclear species (<b>APS-1</b>), whose catalytic efficiency is increased when compared to the homogeneous reaction due to second coordination sphere effects which increase the substrate to complex association constant. The anchored catalyst <b>APS-1</b> can be recovered and reused for subsequent hydrolysis reactions (five times) with only a slight loss in activity. In the presence of DNA, we suggest that <b>1</b> is also converted into the dinuclear active species as observed with <b>APS-1</b>, and both were shown to be efficient in DNA cleavage