Preston A. Beasley

Drug specific, tuning of an ionic liquid's hydrophilic–lipophilic balance to improve water solubility of poorly soluble active pharmaceutical ingredients

Amphotericin B and itraconazole were used to demonstrate that ionic liquids can be designed or chosen to provide tunable hydrophilicity in one ion and lipophilicity in the other allowing one to match the structural requirements needed to solubilize poorly water soluble active pharmaceutical ingredients. These liquid, amphiphilic excipients could be used as both drug delivery systems and solubilization agents to improve the aqueous solubility of many drugs. The solubility in deionized water, simulated gastric fluid, simulated intestinal fluid, and phosphate buffer solution was greatly improved over current methods for drug delivery by utilizing designed ionic liquids as excipients.

Hypergolic Ionic Liquids to Mill, Suspend and Ignite Boron Nanoparticles

Boron nanoparticles prepared by milling in the presence of a hypergolic energetic ionic liquid (EIL) are suspendable in the EIL and the EIL retains hypergolicity leading to the ignition of the boron. This approach allows for incorporation of a variety of nanoscale additives to improve EIL properties, such as energetic density and heat of combustion, while providing stability and safe handling of the nanomaterials.

Graphene and Graphene Oxide Can “Lubricate” Ionic Liquids based on Specific Surface Interactions Leading to Improved Low‐Temperature Hypergolic Performance

Space-qualified lubricants: Graphene and graphene oxide (r-GO) can strongly improve the low-temperature performance of hypergolic ionic liquids by reduction of viscosity. Key to success is to match the graphene type to the specific ionic-liquid functionality.

Synthesis, limitations, and thermal properties of energetically-substituted, protonated imidazolium picrate and nitrate salts and further comparison with their methylated analogs

The possibility of forming simple energetic ionic liquids via the straightforward protonation of heterocyclic amines with nitric or picric acid was explored with 1-alkylimidazoles, 1-alkyl-2-methylimidazoles, and nitro, dinitro, and dicyano-substituted derivatives. The melting points of most of the prepared salts were lower than expected and of the 30 compounds prepared, more than half were found to melt below 100 °C. Limitations in the approach were found as a result of the use of energetic electron withdrawing substituents, such as nitro or cyano, which results in a reduction in nucleophilicity of the heterocycle and an inability to form salts with the acids studied. Interesting thermal behavior was observed with several of the new salts including supercooling and crystallization on heating. Comparison of the simple protonated imidazolium nitrate and picrate salts with their methylated analogs indicated that the protonated ionic liquids do not differ substantially in their melting points from the methylated analogs. However, the thermal stabilities of protonated imidazolium salts are much lower than their alkylated derivatives. Nitrate salts with alkylated cations tend to be more thermally stable than the corresponding picrate salts, but with protonated cations, the picrate salts tend to be approximately 70–80 °C more stable than the nitrate salts. Moreover, accelerating rate calorimetry (ARC) revealed that alkylated salts decompose much less exothermically (in some cases endothermically) than the protonated analogs, and that among all the analyzed salts, the most energetic materials found were protonated 1-methylimidazolium nitrate and 1,2-dimethylimidazolium picrate.

Azolium azolates from reactions of neutral azoles with 1,3-dimethyl-imidazolium-2-carboxylate, 1,2,3-trimethyl-imidazolium hydrogen carbonate, and N,N-dimethyl-pyrrolidinium hydrogen carbonate

Utilizing previously reported synthetic protocols for the halide- and metal-free synthesis of organic salts, we have prepared a new group of imidazolium and pyrrolidinium azolate anion-based salts demonstrating the general applicability of the methodology and expanding our investigation into non ion exchange routes to potentially energetic ionic liquids. Eighteen salts, out of which six exhibit melting points below 100 °C, were prepared by a simple decarboxylation reaction, which resulted in clean formation of the new compounds without the need for extensive purification. The low stability of the H2CO3 by-product, and its decomposition to CO2 and H2O in aqueous media, allows for purification of the salts by evaporation only.

Tuning azolium azolate ionic liquids to promote surface interactions with titanium nanoparticles leading to increased passivation and colloidal stability.

The passivation and stability of suspensions of titanium nanoparticles in azolium azolate ionic liquids can be tuned by introducing metal specific binding sites in the azolate anion.

CCDC 902238: Experimental Crystal Structure Determination

Related Article: Marcin Smiglak, C. Corey Hines, W. Matthew Reichert, Julia L. Shamshina, Preston A. Beasley, Parker D. McCrary, Steven P. Kelley and Robin D. Rogers|2013|New J.Chem.|37|1461|doi:10.1039/C3NJ00147D

CCDC 902237: Experimental Crystal Structure Determination

Related Article: Marcin Smiglak, C. Corey Hines, W. Matthew Reichert, Julia L. Shamshina, Preston A. Beasley, Parker D. McCrary, Steven P. Kelley and Robin D. Rogers|2013|New J.Chem.|37|1461|doi:10.1039/C3NJ00147D