Synthesis, Physicochemical Characterization, Antimicrobial Properties, and DFT/ADMET Calculations of Imidazolium-Based Ionic Liquids with a Homologous Series of Oxychlorine Anions

Imidazolium-based ionic liquids bearing a homologous series of oxychlorine anions-1-butyl-3-methylimidazolium chlorite, chlorate, and perchlorate-were synthesized and characterized to relate anion oxygenation to density, thermal expansivity, viscosity, electrical and molar conductivity, ionicity, and antimicrobial performance. Temperature-dependent measurements were carried out from 293.15 to 323.15 K: density and viscosity were recorded and modeled to obtain thermal expansion coefficients; electrical and molar conductivities were measured under identical conditions; and activation parameters were extracted by Arrhenius analysis for viscous flow and for conductivity. Ionicity was assessed from Walden plots and quantified by vertical deviation from the potassium-chloride reference (Angell approach). Complementary DFT calculations provided optimized ion-pair geometries, noncovalent contact patterns, molecular electrostatic potential maps, and frontier-orbital descriptors. In silico ADMET properties were computed to contextualize pharmacokinetic and safety flags. Antimicrobial activity was evaluated by broth microdilution against <i>Escherichia coli</i>, <i>Staphylococcus aureus</i>, <i>Bacillus cereus</i>, and <i>Candida quilliermondii</i>; [Bmim]Cl was included as a comparator to isolate the effect of anion oxygenation. The combined experimental-computational workflow delineates how chlorite, chlorate, and perchlorate shape physicochemical behavior, ionicity, and bioactivity in [Bmim] ionic liquids, providing design guidance for future applications.