A comparative structural study of ternary graphite intercalation compounds containing alkali metals and linear or branched amines

New donor-type ternary graphite intercalation compounds (GICs) containing alkali metals and branched amines are prepared by direct reaction of graphite with the alkali metal and amine. The new GICs include M(iC3)0.4C15–18 (M = Li, Na; iC3 = iso-propylamine; di = 0.76 nm) with a monolayer intercalate arrangement; and Na(sC4)1.6C18 (sC4 = sec-butylamine; di = 1.34 nm) and Na(iC4)2.0C28 (iC4 = iso-butylamine; di = 1.28 nm) with bilayer arrangements. Li-sC4-GIC and K-iC3-GIC are not formed using this reaction chemistry. M-iC3-GICs show galleries expanded by 0.06 nm more than that for M(nC3)0.7–0.8C16 (M = Li, Na; nC3 = n-propylamine). Unlike the case of rigid-sheet hosts where branched amines intercalate at a lower rate and with lower amine content, M-sC4-GICs and M-iC4-GICs readily form intercalate bilayers.