Crystalline anhydrous α,α-trehalose (polymorph β) and crystalline dihydrate α,α-trehalose: A calorimetric study

The mean values of the standard massic energy of combustion of crystalline anhydrous α,α-trehalose (C12H22O11, polymorph β) and crystalline dihydrate α,α-trehalose (C12H26O13) measured by static-bomb combustion calorimetry in oxygen, at the temperature T=298.15K, are Δcuo=-(16434.05+/-4.50)J.g-1 and Δcuo=-(14816.05+/-3.52)J.g-1, respectively. The standard (po=0.1MPa) molar enthalpy of formation of these compounds were derived from the corresponding standard molar enthalpies of combustion, respectively, ΔfHmo (C12H22O11,cr)=-(2240.9+/-3.9)kJ.mol-1, and ΔfHmo (C12H26O13,cr)=-(2832.6+/-3.6)kJ.mol-1. The values of the standard enthalpies of formation obtained in this work, together with data on enthalpies of solution at infinite dilution (ΔsolH∼) for crystalline dihydrate and amorphous anhydrous trehalose, allow a better insight on the thermodynamic description of the trehalose system which can provide, together with the future research on the subject, a contribution for understanding the metabolism in several organisms, as well as the phase transition between the different polymorphs