Thermal decomposition of lanthanum(III) butyrate in argon atmosphere

•The dehydration of La(C3H7CO2)3·xH2O takes place between 50°C and 120°C.•La(C3H7CO2)3 melts at 180°C.•The decomposition of La(C3H7CO2)3 to La2O2CO3 involves a meta-butyrate intermediate.•CO2 and C3H7COC3H7 (4-heptanone) are released between 250°C and 350°C.•La2O3 is formed as a final decomposition product. The thermal decomposition of La(C3H7CO2)3·xH2O (x≈0.82) was studied in argon during heating at 5K/min. After the loss of bound H2O, the anhydrous butyrate presents at 135°C a phase transition to a mesophase, which turns to an isotropic liquid at 180°C. The decomposition of the anhydrous butyrate is associated to a solidification process. The final decomposition to La2O3 takes place via two intermediate products: La2O(C3H7CO2)4 and La2O2CO3 with release of CO2 and the symmetrical ketone C3H7COC3H7.