Catalytic Properties of a MnIII‐Salen Complex Immobilised in a Pillared Clay by Simultaneous Pillaring/Encapsulation Procedures

Abstract

AbstractThe simultaneous encapsulation of a manganese(III)‐salen complex, [Mn(salhd)Cl], and pillaring of a montmorillonite clay with aluminium polyoxycations was performed using two methods: method A – the [Mn(salhd)Cl] complex was dissolved in ethanol and added to the oligomer solution at a stage when the oligomeric species had already formed; method B – the complex, also dissolved in ethanol, was added to the clay dispersion. After calcination, both materials were Soxhlet extracted to remove the excess complex, and characterised by XRD, nitrogen adsorption at –196 °C, XPS, atomic absorption and FTIR spectroscopy. In both cases, the manganese(III)‐salen complex is mainly physically entrapped within the matrix, although some host–guest interactions with the matrix may be present. Both new materials [Mn(salhd)Cl]@Al‐WYO_A and [Mn(salhd)Cl]@Al‐WYO_B show catalytic activity in the epoxidation of styrene at room temperature with PhIO as oxygen source in acetonitrile. The solids present high styrene epoxide selectivity, and may be reused at least four times. FTIR spectra of the catalysts after the catalytic reactions suggest that during the reaction no structural changes of the pillared clay (PILC) took place, but low extent complex leaching occurred. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)