Thermodynamic properties of ε-Caprolactam and ε-Caprothiolactam

•Energetic characterization of lactam derivatives.•Conformational analysis of ε-caprolactam and ε-caprothiolactam.•Measurement of the massic energies of combustion for ε-caprolactam and ε-caprothiolactam.•Measurement of enthalpy of sublimation for ε-caprolactam and ε-caprothiolactam.•Experimental and computational gas-phase enthalpies of formation.