Heat capacity and Raman spectra of Cr(C5H7O2)3 at low temperature

The heat capacity of Cr(C5H7O2)3 has been measured by the adiabatic method within the temperature range 5–320 K. An anomaly with a maximum at ∼60 K has been discovered which points to the phase transformation of the compound. Anomalous contributions to entropy and enthalpy have been revealed. The thermodynamic functions (entropy, enthalpy and reduced Gibbs energy) at 298.15 K have been calculated using the obtained experimental heat capacity data. The Raman spectra have been measured in the frequency range 60–400 cm−1 and in the temperature range 5–220 K. It has been discovered that a new line (109 cm−1) appears at ∼60 K. The nature of these peculiarities in heat capacity and in Raman spectra is discussed.