Poster ID: EPSCOR0009 - Solvent Synthesis

 Synthesis of Novel Solvent Molecules for use in Solvate Ionic Liquids

Amanda Liske and J. Allred, Dept. of Natural Sciences, Northeastern State University, Tahlequah, OK. Faculty Advisor, Dr. Spence Pilcher, Northeastern State University, Tahlequah, OK.

ABSTRACT
Solvate ionic liquids (SILs) are a subgroup of ionic liquids in which an organic solvent, which contains atoms capable of donating one or more electron pairs, wraps around a solute cation molecule. In the context of petroleum research, SILs created from lithium salts may function as replacements for existing solvents in applications as diverse as heat transfer fluids, lubricants, or electrolyte solutions. Methyl capped ethylene glycols, or “glymes”, and crown ethers are commonly used for the molecular solvent portion of SILs. Replacing glymes with different molecular solvents which can coordinate with cations is a way to expand the array of properties allowed by SILs.

To study the formation and properties of new SILs and as a part of a larger project, this research focused on synthesizing novel solvent molecules by systematically replacing all or part of the oxygen atoms in glymes with tertiary amines. Six different solvents were targeted to be synthesized: 1,2-bis[2-(N,N-diethylamino)ethoxy]ethane (NOON), 1,2-bis-[2-N,Ndimethylamino-2-ethoxy)ethyl]ether (NOOON), 1-[2-(N,N-diethylamino)ethoxy]-2-(2-methoxyethoxy)ethane (OOON), 1-[2-(N,N-dimethylamino-2-ethoxy)ethyl]-2-[2-(2-methoxyethoxy)ethyl]ether (OOOON), 1,2-bis[(2-methoxy-N-ethyl)-N-methyl]ethylenediamine (ONNO), and 1-(N-methyl-N',N'-diethylethylene diamine)-2-(2-methoxyethoxy)ethane (NNOO).

The NOON and NOOOON molecules were prepared using a three-day synthetic procedure involving brominating a triglyme or tetraglyme followed by amination to make the target solvent. Infrared (IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy were used to confirm the structures and purity of the intermediates and products. Initially, the solvents OOON and OOOON produced integration values that were different than expected in the 1H NMR spectra following synthesis. It was deduced that bromination with PBr3 unintentionally cleaved off a methoxy group in addition to substituting the alcohol with bromine. A tosylation procedure utilizing p-toluenesulfonyl chloride proved a viable alternative to bromination and ultimately succeeded in synthesizing OOON and OOOON. The ONNO and NNOO solvents were prepared via a substitution reaction that involved two starting molecules- one containing a primary bromine and one containing nitrogen with lone pairs of electrons. These syntheses yielded acceptable integration values for both target solvents. These six novel solvent molecules and the methods used to produce them can now be applied in further research to determine the effects of solvents containing tertiary amines on the properties of SILs.