On the structural and electronic properties of poly(dicarbon monofluoride):: solid-state semi-empirical INDO study

Three-dimensional semi-empirical quantum chemical calculations of the structural and electronic properties of the fluorine intercalated graphite compound poly(dicarbon monofluoride)-(C2F)(n) have been performed for several possible stacking sequences of puckered trans-cyclohexane chair layers. Such basic structure consisting from carbon hexagons in chair conformation has been confirmed. Furthermore. based on the geometry optimization, 12 structural sequences have been found to provide a local minima, on the potential hypersurface, from which four are considerably more stable and one can assume their statistical distribution in the real poly(dicarbon monofluoride). This is also indicated by comparison with recent Kalpha XES spectra. In such arrangement the maximal entropy contribution leads to the minimum Gibbs energy of the system. Band structure calculations show that the most stable sequences have insulating properties, which implies that the real poly(carbon monofluoride) behaves as an insulator. The conductive properties of some less stable sequences result from particular interlayer interactions. (C) 2003 Elsevier Inc. All rights reserved.