Effect of temperature on the solvation of 15-crown-5 ether in water–ethanol and water–propan-1-ol mixtures

Effect of Base–Acid Properties of Mixtures of Ethanol with Water on the Enthalpy of Solution of Cyclic Ethers in these Mixtures at T = 298.15 K

“…Using the standard solution enthalpy data of cyclic ethers, literature data for 15C5 [ 31 ], and data of the enthalpy of vaporization of cyclic ethers [ 43 , 44 ], the standard solvation enthalpies of cyclic ethers in pure ethanol and in pure water were calculated. It is observed that the standard solvation enthalpy of cyclic ethers in EtOH and W depends linearly on the number of –CH 2 CH 2 O– groups ( ) in the cyclic ether molecules (Eqs.…”

“…1 , the transfer enthalpies of cyclic ethers investigated in this paper are presented as a function of mole fraction of water x w in the mixtures. In order to compare the data obtained, the transfer enthalpy of 15-crown-5 ether (15C5) (calculated using the data of the standard enthalpy of solution of 15C5 [ 31 ]) was included. As is seen in this figure, the shapes of the transfer enthalpy curves of the cyclic ethers investigated are similar to each other.…”

“…

Fig. 1 Transfer enthalpy of cyclic ethers: 1,4-dioxane ( filled square ), 12C4 ( filled circle ), and 15C5 ( filled triangle ) (calculated using the standard enthalpy of solution of 15C5 [ 31 ]) and of 18C6 ( filled inverted triangle ) from water to mixtures as a function of the water mole fraction ( x w ) at 298.15 K

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“…In the high and medium EtOH content region in the mixtures, the change in the function is connected (in my opinion) with the structure of the mixed solvents and interactions of cyclic ether molecules (in particular 15C5 and 18C6) with molecules that are components of the mixtures, i.e. preferential solvation [ 31 ].…”

“…The enthalpy of solution of cyclic ethers in ethanol–water ( ) mixtures was measured at (298.15 ± 0.01) K using an “isoperibol” type calorimeter as described in the literature [ 28 ]. The calorimeter performance was verified on the basis of the standard enthalpies of solution of urea and of KCl (calorimetric standard US, NBS) in water at (298.15 ± 0.01) K [ 29 , 30 ] as was described in our recent publication [ 31 ]. The value of solution enthalpy in water obtained by us from seven measurements for urea is (15.31 ± 0.06) kJ·mol −1 (literature data 15.31 kJ·mol −1 [ 32 ], 15.28 kJ·mol −1 [ 33 ] and 15.30 kJ·mol −1 [ 34 ]) and for KCl is (17.55 ± 0.05) kJ·mol −1 (literature data 17.58 kJ·mol −1 [ 29 , 30 ]).…”