Low temperature molar heat capacities and thermal stability of crystalline artemisinin

The heat capacities of artemisinin in crystal form were measured in the temperature range from 80 to 363 K by an adiabatic calorimeter. Three thermal anomalies were observed at 198, 240, and 312 K. Thermogravimetry and differential thermal analysis from 300 to 700 K showed melting at 420 K, loss of formic acid at 480 K, and further decomposition above 480 K.