One-pot synthesis of lithium alkylzinc alkoxo heterocubanes with a LiZn3O4 core as suitable organometallic precursors for Li-containing ZnO nanocrystals

Abstract

A convenient and efficient synthesis of the stable monolithium alkylzinc alkoxo cubanes {Li(thf)(RZn)(3)(OR')(4)} [R = Me, R' = (i)Pr (1), (t)Bu (2); R = Et, R' = (i)Pr (3), (t)Bu (4)] is reported. They are well soluble in organic solvents and suitable molecular precursors for the formation of Li-containing ZnO nanoparticles. The compounds are accessible by a convenient one-pot reaction of the respective dialkylzinc with lithium alkoxides in the presence of water and can be isolated as white solids in 35-50% yield. Higher yields (80-85%) for 1 and 3 can be achieved by applying excess (i)PrOH instead of H(2)O as protolysis source. The compounds 1-4 were characterized by elemental analyses, multinuclear NMR and FT-IR spectroscopy, and single-crystal X-ray diffraction analysis (1 and 2). Interestingly, thermal treatment of solutions of 1 and 2, respectively, in anhydrous benzyl alcohol at 190 degrees C yields pure and highly crystalline Li-containing ZnO nanoparticles as evidenced by powder X-ray diffraction analysis (PXRD), Transition Electron Microscopy (TEM), FT-IR and (7)Li MAS NMR spectroscopy.