[Fe4L6](8+) cages: encapsulation and catalytic degradation of an insecticide.

Chiral bis(diimine) ligands (derived from chiral enantiopure diamines and 2-formylpyridine) enantioselectively self-assemble with an iron (II) salt to either the tetrahedral cage molecule ΔΔΔΔ-Fe4L6 or its enantiomer, ΛΛΛΛ-Fe4L6. These versatile water-soluble capsules are capable of binding a wide range of organic guests in their large hydrophobic cavities. Among these guests is the neurotoxic insecticide dichlorvos, for which the ΔΔΔΔ-Fe4L6 coordination capsule serves as a competent supramolecular catalyst for its hydrolysis.