Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7842685 | Journal of Molecular Liquids | 2018 | 48 Pages |
Abstract
For a binary mixture of xN-methylimidazole (hereafter abbreviated to N-mim) + (1-x) water, over a full molar fraction range, the mass density, sound velocity, refractive index, viscosity, mixing enthalpy, conductivity, and pH at (298.15, 308.15, 318.15) K and 0.1 MPa, and 1H NMR and 13C NMR at room temperature combined with Ab initio calculations, were measured and carried out. The excess molar volume (VmE), sound deviation (âu), refractive index deviation (ânD), viscosity deviation (âη), excess Gibbs energy of activation of viscous flow (âGâE), molar mixing enthalpy (âmixHm), 1H NMR chemical shift changes of N-mim and water protons (âδH), 13C NMR chemical shift change of N-mim (âδC), sum of the chemical shift changes (ââδH(N-mim), ââδC), and the interaction energy, hydrogen bond length, second-order perturbation stabilization energy, electron density, and the electronic energy density of the trimer hydrogen-bonded complexes were calculated. The values of VmE, âu, ânD, âη, âGâE, and âmixHm were fitted to a Redlich-Kister equation. The extreme positions of these quantities and the chemical shift changes were compared and discussed with regard to the intermolecular interaction between N-mim and water, and a possible molecular interaction scheme was suggested for N-mim added to water. There occurs an ionization process and hydrogen-bonded interactions between N-mim and water. The ionization process may not be neglected at an infinite dilution of water, and hydrogen bonds predominate the primary interaction in the mixture. The predominant hydrogen-bonded complex in the mixture transforms with increasing x, which is consistent with the calculation results.
Related Topics
Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
Haiyun Hou, Baojuan Jiao, Qingzhong Li, Xinlu Lin, Min Liu, Haojun Shi, Li Wang, Songtao Liu,