The thermal decomposition of La(C3H7CO2)(3)center dot xH(2)O (x approximate to 0.82) was studied in argon during heating at 5 K/min. After the loss of bound H2O, the anhydrous butyrate presents at 135 degrees C a phase transition to a mesophase, which turns to an isotropic liquid at 180 degrees 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. (C) 2013 Elsevier B.V. All rights reserved.