1H NMR study of ternary ammonia-alkali metal-graphite intercalation compounds

Abstract

For the first-stage ternary ammonia-alkali metal-graphite intercalation compounds M( NH 3) x C 24 ( x ∼ 4, M = K, Rb, Cs), three sets of triplet 1H NMR spectral lines have been observed at various temperatures and orientations due to the 1H- 1H and 14N- 1H dipolar interactions. We have inferred the structures of these compounds as mobile (liquid-like) intercalant layers of planar M(NH 3) 4 ions in the between the carbon layers. For the intercalated ammonia molecules, the potential barrier is ∼ 0.2 eV and the molecular geometry is very close to the free NH 3 in gas phase.