Enthalpy of Solvation of Monoglyme, Diglyme, Triglyme, Tetraglyme, and Pentaglyme in Mixtures of Water with N,N-Dimethylformamide at 298.15 K

Abstract

The standard molar enthalpies of solution of linear polyethers (LPs) such as 1,2-dimethoxyethane (monoglyme), diethyleneglycol dimethyl ether (diglyme), triethyleneglycol dimethyl ether (triglyme), tetraethyleneglycol dimethyl ether (tetraglyme), and pentaethyleneglycol dimethyl ether (pentaglyme) in a mixture of water and N,N-dimethylformamide were measured at a temperature of 298.15 K. The values of standard molar enthalpy of solution, Δsol H m o, the enthalpic effect of hydrophobic hydration, Hb(H2O), and the enthalpic effect of cyclization of these glymes have been determined. The values of standard molar enthalpy of solution of LPs are more negative than those of their cyclic equivalents. The exothermic enthalpic effect of hydrophobic hydration of LPs increases linearly with the increase in the number of −CH2− groups. The values of the standard molar enthalpy of solution and the enthalpic effect of hydrophobic hydration of LPs calculated in this paper have been compared to those data for cyclic polyethers (CPs) obtained earlier. The contributions of particular groups (−CH2−, −O−, and −CH3) to the enthalpic effect of hydrophobic hydration have been calculated.

Synthesis, crystal structure, theoretical calculation and cytotoxic effect of new Pt(ii), Pd(ii) and Cu(ii) complexes with pyridine-pyrazoles derivatives

“…Lipophilicity is one the most important factors that has influence on a drugs' biological activity. 28 The complex 2 has the highest log P value (À1,82) and exhibits the highest cytotoxicity among the investigated complexes. However, the another important factor is the stability of compound.…”

Temperature-Induced Activation of Graphite Co-intercalation Reactions for Glymes and Crown Ethers in Sodium-Ion Batteries

“…This is different from the conventional Li-ion (Na-ion) concept, where the solvent does not influence the cell voltage; see, e.g., ref . A series of glymes (mono-, di-, tri-, and tetraglyme, abbreviated as 1G, 2G, 3G, and 4G, respectively) have been tested in the meanwhile by several groups. − Long cycle life and high currents can be generally achieved. For example, Cohn et al reported 8000 cycles at 12 A g –1 with 96% capacity retention when using 2G as the solvent .…”

The Group Contribution to the Function Derived from Density and Speed-of-Sound Measurements for Glymes in N,N-Dimethylformamide + Water Mixtures

“…The number of oxyethylene groups ( n ) in a glyme molecule determines its polarity. With an increase in the number of the –OCH 2 CH 2 – groups, the hydrophobic nature of a linear polyether molecule increases [ 15 ]. Open chain polyethylene glycols have been found to be capable of forming complexes with different metal cations in organic solvents, in a similar manner to the macrocyclic polyethers [ 16 , 17 ].…”