After completion of the reaction, the nanocrystals were isolated and purified by precipitation with acetone followed by several cycles of redispersion in toluene and precipitation with acetone. The nanocrystals were characterized by powder XRD and TEM. For two equivalents of TOPO and down to 225 • C, the anatase crystal phase is still detected while no particles were obtained at 200 • C after 3 hours (Figure ). The shape of the nanocrystals in TEM was irregular as expected from previous literature (Figure ). We estimated the size of the crystals by using the Scherrer equation on the anatase reflection at 25 • (Figure ). An increasing amount of TOPO leads to a decrease in the nanocrystal size, with the effect being more pronounced at lower temperature. It is conceivable that the adsorption-desorption kinetics of the TOPO ligand to the nanocrystal surface slows down at lower temperature, therefore impeding growth. For zirconia, the tetragonal crystal phase is consistently retrieved (Figure ). For the reactions with octadecane as co-solvent, the nanocrystals are less colloidally stable and we find that the injection procedure also negatively impacts the quality of the nanocrystals (Figure ). Hence, the procedure outlined here was necessary to obtain accurate kinetics but is less suitable for nanocrystal production. For the syntheses in pure TOPO using different metal concentrations, the size distribution analysis of TEM images suggests that the size of the nanocrystals increases with metal concentration for both Ti and Zr (Figures and).