= Solution
Graphite starts with approximately planar sp2-bonded carbon sheets and delocalized pi electrons. Increasing fluorination introduces carbon–fluorine bonding, disrupts the extended pi system and increasingly produces puckered, more sp3-like local carbon environments. Layer structure and spacing change rather than remaining those of pristine graphite.
The loss of connected graphitic electronic states generally lowers electronic conductivity and can open a large gap as highly fluorinated material is approached. Low-fluorine arrangements can show more complicated doping and defect effects, so a strictly monotonic conductivity curve for every composition is not implied.
Ratios above one fluorine per carbon require attention to edge, defect and multiply fluorinated environments such as CF2 or CF3; they should not be pictured as adding more than one fluorine to every intact carbon in an otherwise unchanged three-neighbor basal network. The variable empirical composition averages over the actual carbon structure.
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