NMR studies of the conformation and motion of tetrahydrofuran in graphite intercalation compounds

摘要

The behavior of tetrahydrofuran (THF) molecules intercalated in graphite layers in compounds Cs(THF)(sub 1.3)C(sub 24) and K(THF)(sub 2.5)C(sub 24) was studied by proton NMR. The graphite layers in these compounds impose a uniform ordering on the THF molecules, giving rise to sharp NMR spectra. Experimental and simulated proton NMR spectra were used to investigate geometry, orientation and conformation of intercalated THF, and to determine whether pseudorotation, a large amplitude low-frequency vibration observed in gaseous THF, can also occur in the constrained environment provided by the graphite intercalation compounds. Deuterium and multiple quantum proton NMR spectra were also simulated in order to determine if these techniques could further refine the proton NMR results.