Convenient Route to Heterometallic Group 4–Zinc Precursors for Binary Oxide Nanomaterials

Abstract

In this study, simple and efficient synthetic routes to a family of uncommon group 4−zinc heterometallic alkoxides were developed. Single-source molecular precursors with the structures [Cp 2 TiZn(μ,η-OR)(THF)Cl 2 ] (1), [Zr 3 Zn 7 (μ 3 -O)-(μ 3 ,η 2 -OR) 3 (μ-OH) 3 (μ,η 2 -OR) 6 (μ,η-OR) 6 Cl 6 ] (2), and [Hf 3 Zn 7 (μ 3 -O)(μ 3 ,η 2 -OR) 3 (μ-OH) 3 (μ,η 2 -OR) 6 (μ,η-OR) 6 Cl 6 ] (3) were prepared via reduction of Cp 2 TiCl 2 with metallic zinc or protonolysis of the metal−cyclopentadienyl bond in Cp 2 M′Cl 2 (M′ = Zr or Hf) in the presence of 2-methoxyethanol (ROH) and Zn(OR) 2 . This synthetic route enables the creation of compounds with well-defined molecular structures and therefore provides precursors suitable for obtaining group 4−zinc oxides. Precursors 1−3 were characterized by elemental analysis, nuclear magnetic resonance and infrared spectroscopies, and single-crystal X-ray diffraction. Compound 1 decomposed at 800−900 °C to give a mixture of binary metal oxides (i.e., Zn 2 Ti 3 O 8 , ZnTiO 3 , or Zn 2 TiO 4 ) and common polymorphs of TiO 2 and ZnO. After calcination at 1000 °C, only TiO 2 and the high-temperature-stable phase Zn 2 TiO 4 were observed. Thermolysis of compounds 2 and 3 gave mixtures of ZnO and ZrO 2 or HfO 2 , respectively. The obtained ZnO−ZrO 2 and ZnO−HfO 2 mixed oxide materials have constant phase compositions across a broad temperature range and therefore are attractive host lattices for Eu 3+ for applications as yellow/red double-light-emitting phosphors. It was established that Eu 3+ ions were successfully introduced into the ZnO and ZrO 2 /HfO 2 lattices. It was revealed that Eu 3+ ions prefer to occupy low-symmetry sites in ZrO 2 /HfO 2 rather than in ZnO.

Crystal structure and Hirshfeld surface analysis of 8-azaniumylquinolinium tetrachloridozincate(II)

“…About 20% of them feature zinc as a structural component (Banci et al, 2002;Andreini & Bertini, 2012). Zinc complexes exhibit a wide range of coordination numbers and coordination spheres, with tetrahedral (Ashurov et al, 2018;Petrus et al, 2020) and octahedral (Ashurov et al, 2011) environments being the most frequently observed.…”

Structural diversity in transition metal-doped titanium oxo-alkoxy complexes: Potential sol-gel intermediates for doped titania nanoparticles and complex titanates

“…Hydrogen atoms and alkoxide ligands have been removed for clarity. Violet is nickel, green is titanium, red is oxygen, dark green is chloride, dark red is bromide, and grey is carbon with metallic Zn (1:2 Ti:Zn ratio) in a mixture of THF and 2-methoxyethanol at room temperature [90]. The two chloride ions from the titanocene dichloride complex were replaced by a chelating 2-methoxyethanol ligand using the excess Zn(OR) 2 to extract the chloride ions to form Zn(OR)Cl and/or ZnCl 2 [91].…”

Synthesis of Heterometallic Zirconium Alkoxide Single-Source Precursors for Bimetallic Oxide Deposition

“…For example, decomposition of the cobalt-zirconium species CoZr 2 (acac) 2 (O i Pr) 8 under autogenic pressure resulted in the formation of spherical ZrO 2 and Co particles, covered in carbon . The thermal decomposition of the zinc-zirconium alkoxide Zr 3 Zn 7 O­(OH) 3 (OR) 15 Cl 6 has also been shown to result in the formation of ZrO 2 crystallites on the surface of ZnO nanowires . A further example is the SSP [Cu 4 Zr 2 O 2 (dmae) 4 (OAc) 8 ]·2H 2 O (dmae = N , N -dimethylaminoethanolato), which produced a CuZrO 3 -CuO composite using aerosol-assisted chemical vapor deposition .…”

“… 20 The thermal decomposition of the zinc-zirconium alkoxide Zr 3 Zn 7 O(OH) 3 (OR) 15 Cl 6 has also been shown to result in the formation of ZrO 2 crystallites on the surface of ZnO nanowires. 21 A further example is the SSP [Cu 4 Zr 2 O 2 (dmae) 4 (OAc) 8 ]·2H 2 O (dmae = N , N -dimethylaminoethanolato), which produced a CuZrO 3 -CuO composite using aerosol-assisted chemical vapor deposition. 22 There are potentially a number of advantages of including transition metals into the zirconia coatings for battery applications, including modifying the ionic conductor behavior of the film and increasing the stability of the protective layer, potentially via substitution of the transition metals into the surface and subsurface layers of the (active) electrode material.…”