Pentagonal_bipyramidal_molecular_geometry
Pentagonal bipyramidal molecular geometry
Molecular structure having atoms at the centre and corners of a pentagonal bipyramid
In chemistry, a pentagonal bipyramid is a molecular geometry with one atom at the centre with seven ligands at the corners of a pentagonal bipyramid. 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 bipyramidal molecular geometry).[1] This is one of the three common shapes for heptacoordinate transition metal complexes, along with the capped octahedron and the capped trigonal prism.[2][3]
Pentagonal bipyramids are claimed to be promising coordination geometries for lanthanide-based single-molecule magnets, since (a) they present no extradiagonal crystal field terms, therefore minimising spin mixing, and (b) all of their diagonal terms are in first approximation protected from low-energy vibrations, minimising vibronic coupling.[4]