FTIR spectroscopic studies of lithium tetrafluoroborate in propylene carbonate+diethyl carbonate mixtures

Abstract

FTIR (Fourier transformed infrared) spectra have been collected and analyzed for solutions of lithium tetrafluoroborate in propylene carbonate (PC), diethyl carbonate (DEC), and PC+DEC mixtures. It has been shown that the carbonyl stretch bands of PC and DEC, the ring of PC and the ether oxygen stretch bands of DEC are all very sensitive to the interaction between Li(+) and the solvent molecules. New shoulders appear and the original bands split with the addition of LiBF4, indicating that a strong interaction between Li(+) and molecules of PC and DEC exists through the oxygen group of C=O and ring of PC and both C=O oxygen and ether oxygen atoms of DEC. In addition, no preferential solvation of Li(+) in LiBF4/PC+DEC solutions was detected.

Keywords: Diethyl carbonate (DEC); FTIR spectroscopy; Lithium tetrafluoroborate; Propylene carbonate (PC).