Domain Analysis in Nanostructured Liquids: A Post‐Molecular Dynamics Study at the Example of Ionic Liquids

Abstract

In the present computational work, we develop a new tool for our trajectory analysis program TRAVIS to analyze the well-known behavior of liquids to separate into microphases. The dissection of the liquid into domains of different subsets, for example, in the case of fluorinated ionic liquids with anionic and cationic head groups (forming together the polar domain), fluorous, and alkyl subsets is followed by radical Voronoi tessellation. This leads to useful average quantities of the subset neighbor count, that is, the domain count that gives the amount of particular domains in the liquid, the domain volume and surface, as well as the isoperimetric quotient, which provides a measure of the deviation of the domains from a spherical shape. Thus, the newly implemented method allows analysis of the domains in terms of their numbers and shapes on a qualitative and also quantitative basis. It is a simple, direct, and automated analysis that does not need evaluation of the structure beforehand in terms of, for example, first solvent shell minima. In the microheterogeneous ionic liquids that we used as examples, the polar subsets always form a single domain in all investigated liquids. Although the fluorous side chains are also more or less connected in one or, maximally, two domains, the alkyl phases are dispersed.

Strong Microheterogeneity in Novel Deep Eutectic Solvents

“…The domain count stems from a radical Voronoi tesselation of the investigated systems where the different sub‐molecular groups are connected when they share at least one Voronoi face with each other. For a more detailed explanation on the methodology of the used domain analyses the reader is referred to . According to the ESP analysis (Figure ) EG is counted as polar as well as all cationic head groups with one spacer CH 2 element and/or the terminal methyl groups.…”

Water in Protic Ionic Liquids: Properties and Use of a New Class of Electrolytes for Energy‐Storage Devices

“…For more details on the simulation methodologies, the reader is referred to our earlier work [27] as well as an upcoming work on IL-water simulations. [29] Concerning the compositions of the simulations, 500 ion pairs of the pure liquid were simulated whereas the 1% water solution was composed of 407 ion pairs along with 93 water molecules. The production run consisted of 15 ns for the pure liquid and the 1% water solution, 5nsf or the 2% water solution, and 1.5 ns for the 3.8 %w ater solution.…”

Hydrogen Bonding of N‐Heterocyclic Carbenes in Solution: Mechanisms of Solvent Reorganization

“…However, proton transfer between the carbene and the alcohol molecules is neglected here, and since it has been shown that the dynamics of water is only slightly influenced by NQEs, whereas the water reorientation mechanism is not affected at all, we expect that this simplification will have no effects on the main conclusions of this study . Trajectories were analyzed with our open source program TRAVIS . In order to model the carbene's side chains as well as the solvent molecules, the OPLS‐AA force field was applied with the Lorentz–Berthelot mixing rules.…”