Anticancer Agents as Design Archetypes: Insights into the Structure–Property Relationships of Ionic Liquids with a Triarylmethyl Moiety

Abstract

A fundamental challenge underlying the design principles of ionic liquids (ILs) entails a lack of understanding into how tailored properties arise from the molecular framework of the constituent ions. Herein, we present detailed analyses of novel functional ILs containing a triarylmethyl (trityl) motif. Combining an empirically driven molecular design, thermophysical analysis, X-ray crystallography, and computational modeling, we achieved an in-depth understanding of structure–property relationships, establishing a coherent correlation with distinct trends between the thermophysical properties and functional diversity of the compound library. We observe a coherent relationship between melting (T m) and glass transition (T g) temperatures and the location and type of chemical modification of the cation. Furthermore, there is an inverse correlation between the simulated dipole moment and the T m/T g of the salts. Specifically, chlorination of the ILs both reduces and reorients the dipole moment, a key property controlling intermolecular interactions, thus allowing for control over T m/T g values. The observed trends are particularly apparent when comparing the phase transitions and dipole moments, allowing for the development of predictive models. Ultimately, trends in structural features and characterized properties align with established studies in physicochemical relationships for ILs, underpinning the formation and stability of these new lipophilic, low-melting salts.

Ionic Liquids with Benzenesulfonate Anions: Nonfluorinated, Thermally Stable Anion Options

“…In addition, in previous work, it was noted that an increase in the dipole moment of the ion generally led to a decrease in the T m . Structural changes of the benzene ring (e.g., incorporation of asymmetrical meta -Cl substituent) increases the dipole moments of the anion, leading to a clear pattern in T m reduction.…”

“…In addition, in previous work, it was noted that an increase in the dipole moment of the ion generally led to a decrease in the T m . 20 Structural changes of the benzene ring (e.g., incorporation Entropy of fusion was calculated from the enthalpy of fusion and melting point data. Uncertainties were calculated from the standard deviation of the mean with at least nine independent trials.…”

Planting the Seeds of a Decision Tree for Ionic Liquids: Steric and Electronic Impacts on Melting Points of Triarylphosponium Ionic Liquids

“…Indeed, we observed this theory to hold true in other related triaryl-bearing compounds. 47 Our previous work also revealed that in addition to the magnitude of the dipole, the direction is also relevant. In brief, changes in the orientation of the cation dipole can allow (or prevent) the formation of cation−cation interactions.…”

Quantum Chemical Insight into 1,2-Shift Rearrangement in Bromination of Allylaryls

“…In this work, we used DFT-based M06-2 X /6-31++G­(d,p) theory and a basis set for prediction of geometry, electron density, and thermochemistry. This combination of theory and basis set has been effectively used in our earlier work to predict molecular geometry and thermochemical properties for ionic and molecular species. − Furthermore, M06 suite of density functionals has been successfully applied to the main group thermochemistry, noncovalent interactions, and excited states . A scaling factor of 0.986 was used for the correction of vibrational frequencies calculated using the M06-2 X /6-31++G­(d,p) level of theory .…”