The effect of hydroxyl groups on the stability and thermodynamic properties of polyhydroxylated xanthones as calculated by density functional theory

► The strength of the hydrogen bonds existed in PHOXTHs is ascertained. ► Good linear relations exist between the thermodynamic properties and NPHOS. ► The relative stability order of PHOXTH congeners is theoretically proposed. ► There is a good relation between Cp,m and the temperature.