Structure and properties of KC 24(Bz) 2, A graphite-potassium-benzene intercalation compound

Abstract

The first-stage KC 24(C 6H 6) 2 intercalation compound (I) is formed by letting undiluted benzene vapor react with the second-stage binary KC 24. Its 1H NMR derivative absorption spectrum shows a single line, with ΔH pp = 2 G over the 77 – 300 K temperature range, which can be ascribed to benzene molecules undergoing reorientation around their hexad axis. This reorientation of the organic molecules must be taken into account when computing geometric dimensions or X-ray diffraction intensities and a model is presented (with the C 6 v axis of the benzene molecules tilted 60° with respect to the c axis) which gives better agreement with the experimental results than the previous ones which took the organic molecules to be parallel or perpendicular to the c axis. E.p.r. measurements on I prove that it is a better electrical conductor than KC 24, both along and across the planes, and a qualitative explanation of this behaviour is given.