Immobilization of Homogeneous Complexes

For example, tungstate and heteropolytungstates have been immobilized by anion exchange with quaternary ammonium-modified silica [66] and polysiloxane 

Molybdenum(VI) complexes of thermally and oxidatively stable polybenzami-dazoles were shown to be recyclable catalysts for epoxidations with TBHP although stability towards slow leaching of molybdenum was not rigorously demonstrated [72]. 

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