Surface-modified imogolite by 3-APS–OsO4 complex: Synthesis, characterization and its application in the dihydroxylation of olefins

We modified the surface of imogolite nanorods by silylation using 3-aminopropyltriethoxysilane (3-APS) and subsequent attachment of osmium tetroxide (OsO4) onto the amine groups of the silylated imogolite surface. In order to characterize surface-modified imogolite by 3-APS–OsO4 complex, powder X-ray diffraction (powder XRD), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet/visible (UV–vis) spectroscopy and X-ray photoelectron spectroscopy (XPS) experiments were carried out, and we verified the formation of the osmium tetroxide complex on the surface-modified imogolite by 3-APS. As a heterogeneous catalyst, this osmium-bound imogolite (I-APS–OsO4) was applied in the achiral dihydroxylation of olefins, and revealed excellent catalytic activity while leaching of osmium was observed. Introduction of chelating ligands instead of the primary amine group to improve the reusability of the catalyst is currently in progress.