Organometallic Mo complex anchored to magnetic iron oxide nanoparticles as highly recyclable epoxidation catalyst

The organometallic fragment [MoI2(CO)(3)] was coordinated to magnetic iron oxide nanoparticles of different sizes (average size of 11 and 30 nm) which have been previously coated with a silica shell and grafted with a pyridine derivative ligand. The Mo loading was found to be approximately 0.37 wt-% Mo and 0.57 wt-% Mo, corresponding to 0.150 mmol(Mo) g(-1) and 0.230 mmol(Mo) g(-1) for materials MNP30-Si-inic-Mo and MNP11-Si-inic-Mo, respectively. Preparation of these organometallic decorated magnetic nanoparticles was further confirmed by evidence obtained from extensive characterization by powder XRD, SEM/TEM analysis, as well as from data of Fe-57 Mossbauer and FTIR spectroscopy. Olefin epoxidation of a variety of substrates promoted by these organometallic nano-hybrid materials using tbhp as oxidant, was performed with very good results. The catalytic studies show that the catalysts yield selectively the desired epoxides of a series of olefins. In addition, these catalysts are found to work under a wide temperature range and over several catalytic cycles without notorious performance loss in most cases. (C) 2014 Elsevier B. V. All rights reserved.