Fluorinated single-wall carbon nanotubes

Fluorinated armchair (10,10) and zigzag (18,0) single-wall carbon nanotubes (F-SWNT) of C2F stoichiometry with five different fluorine atom decorations are studied using density-functional theory and periodic boundary conditions. The most stable armchair F-SWNT isomers (1a and 5a) are metallic and have rr bond chains parallel to the tube axis. Isomer 5a carries every second fluorine atom inside the tube and is 5 kcal mol(-1) more stable than 1a. Fluorinated zigzag tubes are not metallic. The isomer with helical zigzag conjugated pi bonds is the most stable zigzag F-SWNT, but is less stable than 1a. Depending on the fluorination pattern and the tube chirality, the band gaps of the F-SWNT's vary from 2.7 to 0 eV.