title: Superphenalene
text: # Superphenalene
  
  Superphenalene is a very large polycyclic aromatic hydrocarbon (PAH) with chemical formula $C_{96}H_{30}.$ It can be formally considered to consist of three fused superbenzenes (hexa-peri-hexabenzocoronene).
  
  It can be considered as an overlapping structure of three hexa-peri-hexabenzocoronenes arranged symmetrically around a center. These have also been known as building blocks of molecular electronics since 2004 as they form self-assembling columns and nanotubes.
  
  ## Occurrence
  
  It is not known to occur naturally.
  
  ## Properties
  
  Superphenalene has a planar geometry. With 540,000 mesomeric boundary structures, it has significantly more than hexabenzocoronene (250), supernaphthalene (16,100) and also buckminsterfullerene (12,500). The molecule has a threefold symmetry axis perpendicular to the molecule $(C_3).$
  
  