Pentagonal planar molecular geometry
In chemistry, the pentagonal planar molecular geometry describes the shape of compounds where five atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a pentagon. Examples
The only two pentagonal planar species known are the isoelectronic (nine valence electrons) ions  and . Both are derived from the pentagonal bipyramid with two lone pairs occupying the apical positions and the five fluorine atoms all equatorial. References

Stereochemistry
Molecular geometry