Effect of temperature on the solvation of 15-crown-5 ether in water–methanol mixtures

The enthalpies of solution of 15-crown-5 (15C5) ether in methanol–water mixtures have been measured at 293.15–308.15 K. The values of standard enthalpies of solution of 15-crown-5 ether are negative in the region up to about 0.9 mol fraction of water and then they become positive. The relative importance of the solvation mechanism appeared to depend on co-solvent properties. The effect of temperature on the solvation process of 15C5 in the mixture of water with methanol was discussed.