Reactivity of lithium toward propylene carbonate: Infrared reflection absorption spectroscopy studies in ultrahigh vacuum

The vibrational properties of vapor-deposited lithium films exposed to prop ylene carbonate (PC) vapors at room temperature have been examined by infra red reflection-absorption spectroscopy (IRAS) in ultrahigh vacuum (UHV) usi ng a specially designed chamber. The sharply defined spectral features obse rved were found to be incompatible with those of either, lithium propoxide, lithium alkyl carbonate, lithium carbonate, or mixtures thereof. Instead, the IRAS spectrum of PC/Li/Ni was found to be identical to that obtained by exposing Li to 1,2-propanediol vapors under otherwise identical conditions and may thus be attributed to the corresponding alkoxide derivative.