A simple approach to predict molar heat capacity of ionic liquids using group-additivity method

In this work, we proposed a simple approach to predict molar heat capacity of room-temperature ionic liquids by way of adding the contribution of the cations and anions to the property. The starting point was estimation of the contribution of the cation [Bmim+] to the molar heat capacity at a particular temperature by way of semi-empirical quantum mechanical calculation of the fully optimized geometric structure of the reference cation using the PM3 package of HyperChem 8. From this computed molar heat capacity contribution to the property of the ionic liquid, the molar heat capacity of the other ionic liquids were predicted and compared with the values reported in the literature. The overall AAD for all the 3149 data points of the 32 considered ionic liquids was 0.69%, which is acceptable.