Synthesis, isolation, and redispersion of resorcinarene-capped anatase TiO2 nanoparticles in nonaqueous solvents

C-undodecylcalix[4]-resorcinarene (C11-resorcinarene)-capped anatase TiO2 nanoparticles have been synthesized and could be isolated and redispersed in different nonaqueous solvents. The adsorption of C11-resorcinarene onto the surface of TiO2 nanoparticles led the shifting of the onset wavelength of the optical absorption in the visible range along with a broad band centered at 422 nm corresponding to ligand-to-metal charge transfer transition within the surface titanium(IV)–C11-resorcinarene complex. The interaction of TiO2 nanoparticle with C11-resorcinarenes was investigated by photoluminescence (PL). Proton nuclear magnetic resonance (1H NMR) spectroscopy study revealed that the C11-resorcenarene molecules adsorbed chemically onto the surfaces of TiO2 nanoparticles. The average particle diameter of bare anatase TiO2 and C11-resorcinarene-capped TiO2 was determined using transmission electron microscopy (TEM) and was found to be equal to ca. 5 nm.

Surface modification of anatase TiO2 nanoparticles has been made by the macrocyclic ligand C11-resorcinarene. Modified TiO2 nanoparticles show the onset wavelength of the optical absorption in the visible range, at 663 nm.Figure optionsDownload as PowerPoint slide