| Summary: | To gain a deeper understanding of the TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> solvation effects in multi-component ionic liquids, we performed ab initio molecular dynamics simulations of 1-butyl-3-methylimidazolium [C<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>C<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>1</mn></msub></semantics></math></inline-formula>Im]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>+</mo></msup></semantics></math></inline-formula>, tetrafluoroborate [BF<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula>, chloride [Cl]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula> both with and without water and titanium tetrachloride TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>. Complex interactions between cations and anions are observed in all investigated systems. By further addition of water and TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> this complex interaction network is extended. Observations of the radial distribution functions and number integrals show that water and TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> not only compete with each other to interact mainly with [Cl]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula>, which strongly influences the cation-[BF<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula> interaction, but also interact with each other, which leads to the fact that in certain systems the cation-anion interaction is enhanced. Further investigations of the Voronoi polyhedra analysis have demonstrated that water has a greater impact on the nanosegregated system than TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> which is also due to the fact of the shear amount of water relative to all other components and its higher mobility compared to TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>. Overall, the polar network of the IL mixture collapses by including water and TiCl<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>. In the case of [Cl]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula> chloride enters the water continuum, while [BF<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>]<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula> remains largely unaffected, which deeply affects the interaction of the ionic liquid (IL) network.
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