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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.

In this study, an efficient procedure for the synthesis of uncommon group 4–lanthanide oxo-alkoxide derivatives was developed. Heterometallic clusters with the structures [La2Ti4(μ4-O)2(μ3-OEt)2(μ-OEt)8(OEt)6(Cl)2(HOEt)2] (1), [La2Zr2(μ3-O)­(μ-OEt)5(μ-Cl)­(OEt)2(HOEt)4(Cl)4] n (2), [La2Hf2(μ3-O)­(μ-OEt)5(μ-Cl)­(OEt)2(HOEt)4(Cl)4] n (3), [Nd2Ti4(μ4-O)2(μ3-OEt)2(μ-OEt)8(OEt)6(HOEt)2(Cl)2] (4), [Nd4Zr4(μ3-O)2(μ-OEt)10(μ-Cl)4(OEt)8(HOEt)10(Cl)2] (5), and [Nd4Hf4(μ3-O)2(μ-OEt)10(μ-Cl)4(OEt)8(HOEt)10(Cl)2] (6) were synthesized via the reaction of a metallocene dichloride, Cp2M′Cl2 (where M′ = Ti, Zr, and Hf), and metallic lanthanum or neodymium in the presence of excess ethanol. This procedure gave crystalline precursors with molecular stoichiometries suitable for obtaining group 4–lanthanide oxide materials. Compounds 1–6 were examined by analytical and spectroscopic techniques and single-crystal X-ray diffraction. The magnetic properties of 5 and 6 were investigated by using direct and alternating current (dc and ac) susceptibility measurements. The results indicated weak antiferromagnetic interactions between NdIII ions and a field-supported slow magnetic relaxation. Lanthanum–titanium compound 1 decomposed at 950 °C to give the perovskite compound La0.66TiO3 and small amounts of rutile TiO2. Under the same conditions, 4 decomposed to give a mixture of Nd4Ti9O24 and Nd0.66TiO3. When 4 was calcined at 1300 °C, decomposition of Nd4Ti9O24 to Nd0.66TiO3 and TiO2 was observed. Calcination of 2, 3, 5, and 6 at 950–1500 °C led to the selective formation of heterometallic La2Zr2O7, La2Hf2O7, Nd2Zr2O7, and Nd2Hf2O7 phases, respectively.