Etude par diffraction des rayons X de la penetration du benzene dans KC 24

Abstract

The intercalation of benzene in KC 24 is fast (less than half an hour) and lead to the disorganization of the lamellar binary compound crystal structure. The second stage lamellar compound is dismutated to the first stage one. The latter is modified to give a benzene inserted first stage which is called the first phase. The reorganization is very slow: several weeks are needed to the disappearance of the second stage binary compound and of the first phase one. At the end appear the third stage binary compound, and a second phase product, which is the result of the intercalation of one molecule of benzene in the first phase (Table 1). The increases of the thickness of filled layers in lamellar compounds is explained in Fig. 2 by the benzene molecule behaving as an extra graphite layer. At low temperature (− 100°C), we get the hkl reflections which confirm our hypothesis (Table 2). The first phase has an identity period of 18.8 Å which is corresponding to a 9.4 Å thickness of filled layer: the molecule of benzene is intercalated between the potassium unit and the graphite layer. The second phase has an identity period of 25.8 Å, corresponding to a thickness of filled layer of 12.9 Å, the potassium unit is then inserted between two molecules of benzene, the latter being parallel to the graphite layers.