The spatial arrangement of sp3d3 hybrid orbitals is pentagonal bipyramidal.
Iodine heptafluoride (IF7):
The electronic configuration of the Iodine atom in the ground state is [Kr]4d105s25p5.
Since the formation of IF7 requires 7 unpaired electrons, the iodine atom promotes three of its electrons (one from 5s orbital and two from 5p sublevel) into empty 5d orbitals. This state is referred to as the third excited state.
- The iodine atom undergoes sp3d3 hybridization in the third excited state to give 7 half-filled sp3d3 hybrid orbitals in pentagonal bipyramidal symmetry. These will form 7 σsp3d3-p bonds with fluorine atoms.
- Thus, the shape of IF7 is pentagonal bipyramidal.