title: tert-Butyl(tert-butoxy)zinc hydroxides: hybrid models for single-source precursors of ZnO nanocrystals.
abstract: Alkylzinc alkoxides, [RZnOR']4, have received much attention as efficient precursors of ZnO nanocrystals (NCs), and their "Zn4O4 " heterocubane core has been regarded as a "preorganized ZnO". A comprehensive investigation of the synthesis and characterization of a new family of tert-butyl(tert-butoxy)zinc hydroxides, [(tBu)4 Zn4 (μ3-OtBu)x (μ3-OH)4-x], as model single-source precursors of ZnO NCs is reported. The direct reaction between well-defined [tBuZnOH]6 (16) and [tBuZnOtBu]4 (24) in various molar ratios allows the isolation of new mixed cubane aggregates as crystalline solids in a high yield: [(tBu)4 Zn4 (μ3-OtBu)3 (μ3-OH)] (3), [(tBu)4Zn4 (μ3-OtBu)2 (μ3-OH)2] (4), [(tBu)4 Zn4 (μ3-OtBu)(μ3-OH)3] (5). The resulting products were characterized in solution by (1) H NMR and IR spectroscopy, and in the solid state by single-crystal X-ray diffraction. The thermal transformations of 2-5 were monitored by in situ variable-temperature powder X-ray diffraction and thermogravimetric measurements. The investigation showed that the Zn-OH groups appeared to be a desirable feature for the solid-state synthesis of ZnO NCs that significantly decreased the decomposition temperature of crystalline precursors 3-5.
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland).
authors.forename: Kamil
authors.initials: K
authors.lastname: Sokołowski
authors.forename: Iwona
authors.initials: I
authors.lastname: Justyniak
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bury
authors.forename: Justyna
authors.initials: J
authors.lastname: Grzonka
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kaszkur
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Mąkolski
authors.forename: Michał
authors.initials: M
authors.lastname: Dutkiewicz
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Lewalska
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Krajewska
authors.forename: Dominik
authors.initials: D
authors.lastname: Kubicki
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wójcik
authors.forename: Krzysztof J
authors.initials: KJ
authors.lastname: Kurzydłowski
authors.forename: Janusz
authors.initials: J
authors.lastname: Lewiński
keywords: alkoxides; hydroxides; zinc; zinc oxide