Pentagonal bipyramidal molecular geometry

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Idealized structure of a molecule with pentagonal-bipyramidal coordination geometry.
Structure of iodine heptafluoride, an example of a molecule with the pentagonal-bipyramidal coordination geometry.

In chemistry, a pentagonal bipyramid (or dipyramid) is a molecular geometry with one atom at the centre with seven ligands at the corners of a pentagonal dipyramid. A perfect pentagonal bipyramid belongs to the molecular point group D5h . The pentagonal bipyramid is a case where bond angles surrounding an atom are not identical (see also Trigonal bipyramid molecular geometry).[1] Other seven coordinate geometries include the mono-capped octahedron and mono-capped trigonal prism. A variety of transition metal complexes adopt heptacoordination, but the symmetry is usually lower than D5h.


  • Iodine heptafluoride (IF7) with 7 bonding groups
  • Peroxo Cr(IV)-complexes, e.g. [Cr(O2)2(NH3)3] where the peroxo groups occupy four of the planar positions.


  1. ^ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999). Advanced Inorganic Chemistry (6th Edn.) New York:Wiley-Interscience. ISBN 0-471-19957-5.

External links[edit]

  • [1] - Images of IF7
  • 3D Chem - Chemistry, Structures, and 3D Molecules
  • IUMSC - Indiana University Molecular Structure Center