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

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
(Tm) and glass transition (Tg) 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 Tm/Tg 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 Tm/Tg 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.