Accession Number : ADA311539

Title :   Chemistry and Electrochemistry in Lewis Acid and Superacid Ionic Liquids.

Descriptive Note : Final rept. 1 Jan 94-30 Jun 96,

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s) : Osteryoung, Robert A.

PDF Url : ADA311539

Report Date : 30 JUL 1996

Pagination or Media Count : 25

Abstract : Studies of ambient temperature chloroaluminate ionic liquids composed of aluminum chloride and 1-ethyl-3-methylimidazolium chloride were carried out. The major activity involved studies in alkali halide buffered neutral melts. We have observed that these buffered melts exhibit a 'latent acidity'. Weak Lewis bases, B:, which are uncomplexed by AlCl3 in an unbuffered neutral melt, form AlCl3 adducts in a buffered melt. This occurs because the equilibrium B: + AlCl4(-) + Na(+) = B:AlCl3 + NaCl(s) is driven to the right by the precipitation of NaCl(s). The extent to which the reaction takes place depends quantitatively on the Na(+)I. ROESY NMR was carried out to obtain information of local structure in basic chloroaluminate ionic liquids. The ROESY spectra clearly showed cross-peaks due to intramolecular and intermolecular NOE transfers between various protons on the ring system. This confirmed hydrogen bonding between chloride and various ring hydrogen giving rise to structure in the basic melts. Battery related studies involving the use of an additive in the neutral buffered melts to passivate and minimize corrosion of Na and Li surfaces were carried out. SOCl2 was found to be superior to HCl as a passivating agent.

Descriptors :   *ALUMINUM COMPOUNDS, *LIQUIDS, *ELECTROCHEMISTRY, *CHEMISTRY, *CHLORINE, *IONIC CURRENT, BUFFERS, HYDROGEN BONDS, CORROSION, METHYL RADICALS, NEUTRAL, MELTS, SODIUM, PROTONS, LITHIUM, PRECIPITATION, CHEMICAL REACTIONS, CHLORIDES, HALIDES, MOLECULAR STRUCTURE, MOLECULE MOLECULE INTERACTIONS, SULFUR, RINGS, CHEMICAL EQUILIBRIUM, ETHYL RADICALS, ACIDS, ALKALI METALS, IMIDAZOLES.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE