Final answer:
Although the pentagonal pyramidal geometry is not typically encountered, molecules with five electron pairs around the central atom often display a trigonal bipyramidal geometry, such as PF5.
Step-by-step explanation:
The question asks whether there are any compounds with pentagonal pyramidal molecular geometry. The molecular geometries derived from VSEPR theory, including pentagonal bipyramids, square antiprisms, and dodecahedral geometries, are commonly seen in complexes with coordination numbers of seven and eight.
However, the pentagonal pyramidal geometry is not commonly encountered. A molecule with five electron pairs around the central atom, including no lone pairs, will usually adopt a trigonal bipyramidal molecular geometry, with phosphorus pentafluoride (PF5) being a typical example.