Mg. Debacker et al., LITHIUM-ETHYLAMINE AND LITHIUM-SODIUM-ETHYLAMINE SYSTEMS - A NONMETALLIC LIQUID ELECTRIDE AND THE LOWEST MELTING FUSED SALT, Journal of the American Chemical Society, 116(15), 1994, pp. 6570-6576
Phase equilibria and compound formation in two new alkali metal-amine
systems were studied by differential thermal analysis (DTA), EPR, NMR,
and magnetic susceptibility methods. Lithium and ethylamine (EtNH(2))
mixtures with the nominal formula Li(EtNH(2))(n) were studied for n =
2-16. A eutectic with n approximate to 5 melting at T-E = 176.5 +/- 0
.5 K is present. The presence of an endotherm at T-E from n = 2-16 pre
cludes the existence of solid compounds in this composition range unle
ss they melt with decomposition at the eutectic temperature or decompo
se at the temperature of a solid-solid transition (T = 124 +/- 1 K). E
PR line shapes indicate that neither the solid nor the solutions are m
etallic, and magnetic susceptibilities show that these deep blue-black
systems are essentially diamagnetic. Samples that contained equimolar
lithium and sodium in ethylamine, which had the nominal formula LiNa(
EtNH(2))(n), were studied for n = 1-32. Alkali metal NMR studies show
that Li+ and Na- are present in both the liquid and solid phases. A sh
iny gold eutectic solution with n = 5-5.5 freezes at 171.3 +/- 0.5 K,
and a compound with n = 4 melts incongruently at 217.8 +/- 0.4 K. Ther
e is some evidence for compound formation with n = 2-3.