Search

Abstract: A semi-molecular theory has been employed to predict temperature dependent Stokes shift dynamics of a dipolar probe in sodium 2,5,8,11-tetraoxatridecan-13-oate ([Na][TOTO]), and compared with imidazolium ionic liquids (ILs). Predicted dynamic Stokes shift for [Na][TOTO]is ∼60–70% of that calculated for imidazolium ILs. The calculated biphasic dynamics is, however, extremely slow because of large viscosity, average solvation time (〈τ ss〉) being in ∼1s–10ns range at 254⩽ T/(K)⩽344. This is much slower than those in imidazolium ILs (0.1⩽〈τ ss〉/ns⩽6 at 278⩽ T/(K)⩽338). Predicted temperature dependence of shift is very weak and suggests near-Arrhenius behavior for the dynamics. [Copyright &y& Elsevier]

Abstract: Fluorescence dynamics of a polar solute probe in molten (CH3CONH2 +Ca(NO3)2·4.37H2O) mixtures have been measured in order to probe the solute–medium interactions in such complex systems. Steady state and time-resolved measurements bear no signatures of mega-value of the static dielectric constant, strong heterogeneity and extremely slow relaxation times reported in dielectric relaxation experiments for these molten mixtures. Subsequent applications of a semi-molecular theory reveal both the solute–medium dipole–dipole and ion–dipole interactions contribute significantly to the measured Stokes’ shifts. Calculated average solvation times in the underdamped and overdamped limits of frictional solvent response agree semi-quantitatively with those from time-resolved measurements. [ABSTRACT FROM AUTHOR]

[Display omitted] • The 3D Reference Interaction Site Model is used to explore liquid oleyl alcohol. • The 3D-RISM simulations produced the liquid oleyl alcohol structure qualitatively similar to the MD simulation. • The united atom TRAPPE force field is used for bulk susceptibility calculation of the liquid. • The molecular partitioning in alcohol/water media is calculated with RMSD of 0.48 unit. • A new QSAR model is presented for the partition function calculation. The 3D-RISM-KH molecular solvation theory is applied to liquid long chain unsaturated oleyl alcohol to explore the structure of the liquid and to calculate alcohol/water partition coefficients. The united atom TraPPE force field parameters resulted in comparable structural information between RISM and MD simulations. The RISM theory and the MD simulation point to a relatively ordered liquid structure of oleyl alcohol. The molecular partition coefficients were computed with a root mean square deviation of 0.48 unit via a predictive quantitative structure activity relationship. [ABSTRACT FROM AUTHOR]