D2O-H2O solvent isotope effects on the enthalpy of 1,1,3,3-tetramethyl-2-thiourea hydration at temperatures from (278.15 to 313.15) K and ambient pressure
Ivanov, E. V.[Evgeniy V.], Batov, D. V.[Dmitriy V.], Abrosimov, V. K.
The enthalpies of solution of 1,1,3,3-tetramethyl-2-thiourea (TMTU) in ordinary (H2O) and heavy (D2O) water were measured at (278.15, 283.15, 288.15, 298.15, and 313.15) K and atmospheric pressure. Standard molar enthalpies and heat capacities of solution and hydration, together with D2OH2O solvent isotope effects (IEs) on these quantities, were calculated. It was established that, unlike the process of forming aqueous 1,1,3,3-tetramethyl-2-urea (TMU), the dissolution of TMTU in both H2O and D2O is an endothermic effect over the whole temperature range studied, and the standard enthalpy-isotopic effect undergoes a negative-to-positive sign inversion nearby of T = 304 K. Going from TMTU to TMU, the standard heat capacity of solution (hydration) and corresponding IE become less positive.
Compounds
#
Formula
Name
1
C5H12N2S
1,1,3,3-tetramethyl-2-thiourea
2
H2O
water
3
D2O
water-d2
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.