摘要 |
The tris(trimethylsilyl)silanol (H-SST) ligand can be reacted with a Group 4 or 5 metal alkoxides in a solvent to form an SST-modified metal alkoxide precursor. Exemplary Group 4 precursors include [Ti(SST)2(OR)2] (OR=OPri, OBut, ONep); [Ti(SST)3(OBun)]; [Zr(SST)2(OBut)2(py)]; [Zr(SST)3(OR)] (OR=OBut, ONep); [Hf(SST)2(OBut)2]; and [Hf(SST)2(ONep)2(py)n] (n=1, 2), where OPri=OCH(CH3)2, OBut=OC(CH3)3, OBun=O(CH2)3CH3, ONep=OCH2C(CH3)3, and py=pyridine. Exemplary Group 5 precursors include [V(SST)3(py)2]; [Nb(SST)3(OEt)2]; [Nb(O)(SST)3(py)]; 2[H][(Nb(μ-O)2(SST))6(μ6-O)]; [Nb8O10(OEt)18(SST)2.⅕Na2O]; [Ta(SST)(μ-OEt)(OEt)3]2; and [Ta(SST)3(OEt)2]; where OEt=OCH2CH3. When thermally processed, the precursors can form unusual core-shell nanoparticles. For example, HfO2/SiO2 core/shell nanoparticles have demonstrated resistance to damage in extreme irradiation and thermal environments. |