Low-temperature heat capacity of tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium

Abstract The heat capacity of tetrakis (2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium (Zr(C 11 H 19 O 2 ) 4 ) was measured over the temperature range (9–306) K by adiabatic-shield calorimetry and found to be without transitions or thermal anomalies. The data obtained were used to calculate its thermodynamic functions (entropy, enthalpy, reduced Gibbs energy) in the range (0–306) K. They have the following values at 298.15 K: C° p  = (1195.7 ± 1.8) J·K −1 ·mol −1 , Δ 0 298.15 S° m  = (1298 ± 3) J·K −1 ·mol −1 , Δ 0 298.15 H° m  = (194.7 ± 0.3) kJ·mol −1 , Φ° m  = (645.2 ± 1.9) J·K −1 ·mol −1 . The value of the absolute entropy were used to calculate the entropy of formation of Zr(C 11 H 19 O 2 ) 4 at T  = 298.15 K.