Thermal decomposition of yttrium(III) hexanoate in argon

• Yttrium(III) hexanoate hydrate (Y(C5H11CO2)3·1.2H2O was prepared and characterized.
• Y(C5H11CO2)3 melts between 40 °C and 110 °C.
• Solidification occurs upon further heating between 315 °C and 335 °C.
• CO2 and C5H11COC5H11 (6-undecanone) are released between 280 °C and 490 °C.
• The decomposition of Y(C5H11CO2)3 to Y2O3 proceeds through Y2O2CO3.

The thermal decomposition of yttrium(III) hexanoate (Y(C5H11CO2)3)·xH2O in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction at a laboratory Cu-tube source and in-situ experiments at a synchrotron radiation source as well as hot-stage optical microscopy. Dehydration occurs between 40 °C and 110 °C and is accompanied by a transition from solid to liquid crystalline state. At the onset of the main decomposition stage of the anhydrous Y(C5H11CO2)3, solidification takes place in the 315–335 °C range. Y(C5H11CO2)3 decomposes in a single step into Y2O2CO3 with release of CO2 and 6-undecanone between 280 °C and 490 °C. A side reaction appears to yield elemental carbon and volatile decane (C10H22). Y2O2CO3 is converted to Y2O3 with release of CO2 between 500 °C and 975 °C.