Direct thermodynamic characterization of solid-state reactions by isothermal calorimetry

Despite the growing importance of solid-state reactions, their thermodynamic characterization has largely remained unexplored. This is in part due to the lack of methodology for measuring the heat effects related to reactions between solid reactants. We address here this gap and report on the first direct thermodynamic study of chemical reactions between solid reactants by isothermal calorimetry. Three reaction classes, cationic host-guest complex formation, molecular co-crystallization, and Baeyer-Villiger oxidation were investigated, showcasing the versatility of the devised methodology to provide detailed insight into the enthalpy changes related to various reactions. The reliability of the method was confirmed by correlation with the values obtained via solution calorimetry using Hess's law. The thermodynamic characterization of solid-state reactions described here will enable a deeper understanding of the factors governing solid-state processes. Methodology for direct measurement of reaction enthalpy by isothermal calorimetry has been developed and applied for various reactions in solid state.

Automated summary

This paper reports on the first direct thermodynamic study of chemical reactions between solid reactants using isothermal calorimetry. Three different types of reactions were investigated, and the results were compared with those obtained via solution calorimetry to confirm the reliability of the method. This work is important for gaining a deeper understanding of the factors governing solid-state processes.