tert ‐Butyl( tert ‐butoxy)zinc Hydroxides: Hybrid Models for Single‐Source Precursors of ZnO Nanocrystals

Alkylzinc alkoxides, [RZnOR′] 4 , have received much attention as efficient precursors of ZnO nanocrystals (NCs), and their “Zn 4 O 4 ” 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, [( t Bu) 4 Zn 4 (μ 3 ‐O t Bu) x (μ 3 ‐OH) 4− x ], as model single‐source precursors of ZnO NCs is reported. The direct reaction between well‐defined [ t BuZnOH] 6 ( 1 6 ) and [ t BuZnO t Bu] 4 ( 2 4 ) in various molar ratios allows the isolation of new mixed cubane aggregates as crystalline solids in a high yield: [( t Bu) 4 Zn 4 (μ 3 ‐O t Bu) 3 (μ 3 ‐OH)] ( 3 ), [( t Bu) 4 Zn 4 (μ 3 ‐O t Bu) 2 (μ 3 ‐OH) 2 ] ( 4 ), [( t Bu) 4 Zn 4 (μ 3 ‐O t Bu)(μ 3 ‐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 ZnOH 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 .