Neat and Rapid Preparation of Hydrophobic Magnetic Ionic Liquids Composed of Transition Metal Chelates Featuring In-situ Formation Capabilities in Aqueous Matrices
- Ames Laboratory (AMES), Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
- Univ. of Alabama, Tuscaloosa, AL (United States)
- Ames Laboratory (AMES), Ames, IA (United States)
Magnetic ionic liquids (MILs) form a subclass of ionic liquids (ILs) that possess paramagnetic properties and can respond to an external magnetic field, facilitating ease of manipulation in immiscible solvents. Despite being popular as solvents in catalysis, organic synthesis, and separations, MILs are acquired through complex and labor-intensive synthetic/purification routes that increase cost, consume precious time, and require expertise in organic synthesis. To date, no study has successfully developed a highly simplified and easy-to-follow procedure for MIL preparation that can rapidly produce MILs and eliminate the need to purify them. In this study, transition metal-containing bis[(trifluoromethyl)sulfonyl]imide [NTf2-] salts and imidazoles, diglycolamides, and O-donor ligands were used to produce hydrophobic MILs that could maintain their chemical integrity under water for over 6 months. A neat heat/stir method was employed to form MILs for long-term storage or later use while an ¬in-situ method was used to generate the same MIL under 30 seconds in the bulk presence of water. Viscosity values as low as 198.3 cP were obtained that were comparable to previous classes of paramagnetic solvents. MILs were found to be soluble in non-polar solvents such as hexane at concentrations of up to 50% (w/v) MIL-to-solvent ratio while being insoluble in water even at 0.01% (w/v). Effective magnetic moment values for MILs ranged from 2.78 to 5.16 Bohr magnetons (µB) and were observed to be dependent on the metal center in the [NTf2-] salts. The solvents possessed excellent thermal stabilities with TODGA-based MILs exhibiting structural resilience up to 345 °C. The synthetic design of these MILs has successfully achieved the primary objective of facilitating easy access to magnetoactive solvents by reducing their preparation to a simple step consisting of mixing 2 readily available reagents to expedite production in high-throughput laboratories where these compounds can be incorporated in automated separations and analytical testing systems where their magnetic properties can be conveniently exploited.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); National Science Foundation (NSF); USDOE
- Grant/Contract Number:
- AC02-07CH11358; CHE-2203891
- OSTI ID:
- 2325544
- Alternate ID(s):
- OSTI ID: 2323281
- Report Number(s):
- IS-J-11,282
- Journal Information:
- New Journal of Chemistry, Vol. 48, Issue 15; ISSN 1144-0546
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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