The structure of IF7 is
The structure is pentagonal bipyramid having sp3d3 hybridisation as given below :
Fb – I – Fb = 72º (5 number) ; Fd – I – Fa = 90º (10 number)
Fb – I bond length = 1.858 ± 0.004 Å ; Fa – I bond length = 1.786 ± 0.007 Å.
To determine the structure of IF7, we analyze its electron geometry and molecular shape using VSEPR theory.
Iodine (I) has 7 valence electrons. Each fluorine (F) contributes 1 electron. Total valence electrons:
Iodine forms 7 bonds with fluorine atoms and has 3 lone pairs (from 14 electrons total). Steric number = number of atoms bonded + number of lone pairs:
This corresponds to a pentagonal bipyramidal electron geometry.
With no lone pairs on the central atom in the bonding positions (all are bonding pairs), the molecular shape is also pentagonal bipyramidal.
The structure of IF7 is pentagonal bipyramid.
Steric Number (SN) = Number of bonded atoms + Number of lone pairs
For SN=7, electron geometry is pentagonal bipyramidal; if all are bonding pairs, molecular shape is the same.
Hybridization for pentagonal bipyramidal geometry is .