Phase transition in Fe(C11O2H19)3 at 115.25 K

The heat capacity for tris-dipivaloylmethanate of iron Fe(C11O2H19)3 within a temperature range 57–316 K has been measured by the adiabatic method. An anomaly of heat capacity has been discovered with a maximum at ∼115 K, which points to the phase transformation of the Fe(C11O2H19)3 complex. Anomalous contributions to entropy and enthalpy have been revealed. The anomalous entropy equals R ln 2 in the limits of experimental accuracy. The possible reason of phase transition is considered.