Extended X-ray absorption fine structure (EXAFS) measurements are presented for dilute graphite-Br2 intercalation compounds containing 0.27 mole % and 0.75 mole % Br2. Intercalated Br2 molecules are found to have a BrBr distance of 2.34 ± 0.02 A ̊ and predominate in the 0.75% sample. A unique feature of the present work is the discovery of another type of bromine molecule with a BrBr distance of 2.53 ± 0.03 A ̊. This molecule seems to be associated with defect or edge sites and predominates in the 0.27% sample. It is reasonable to speculate that this molecule acts like a "can opener", preparing the graphite planes for intercalation. The implication of these results with respect to charge transfer is discussed, and it is estimated that roughly 0.16 electrons are transferred to each intercalated molecule, while ∼0.6 electrons are transferred to each "can opener" molecule.
|Number of pages||7|
|State||Published - Apr 1980|