Fe₃O₄ Nanoparticle Supported Crown Ethers

Significance

The authors prepared the magnetically separable crown ethers 1 (15-C-5) and 2 (18-C-6) through the immobilization of the crown ethers on the surface of magnetite (Fe₃O₄) nanoparticles (average diameter = 12 nm) (eq. 1). The catalytic activity of the crown ethers supported by magnetic nanoparticles was examined for halogen exchange of 1-bromooctane with KI (eq. 2) and nucleophilic substitution of benzyl bromide with potassium acetate (eq. 3) under solid-liquid phase-transfer-catalytic reaction conditions. Catalyst 2 was readily separated from the reaction mixture using an external magnet and was reused eight times without loss of catalytic activity.