Metal diolates: useful precursors for tailor-made oxides prepared at low temperatures
Diolates of titanium and heterometallic diolates of the combinations Mg/Si, Mg/Ti, Mg/Zr and Ti/Si were prepared by reacting alcoholates [e.g. Ti(OC2H5)4 , Mg(OCH3)2 ·CH3OH] with α,ω-diols like pentane-1,5-diol. The resulting diolates are probably of polymeric nature and do not form single crystals. Structural information was obtained by infrared spectroscopy, thermal analysis and X-ray absorption spectroscopy at the Mg and Si K-edges. Thermal decomposition of such diolates led to oxides with distinct morphology at comparatively low temperatures (540–800 °C). For the heterometallic diolates the thermal decomposition in most cases led to binary, sometimes metastable oxides. The morphology of the oxides strongly depended on the nature of the precursor.