Numford
Hybridisation

Hybridisation of IF₇

I is sp³d³ hybridised (hybridization by the VSEPR count): 7 sigma bonds and no lone pairs give a pentagonal bipyramidal shape, bond angle 72° and 90°.

FFFFIFFF
  • I
  • F

IF₇Iodine heptafluoride

Pentagonal bipyramidal

AB₇: 7 bond pairs, no lone pairs

  • Hybridisationsp³d³
  • Bond angle72° and 90°
  • Polaritynon-polar

Why this shape

  1. I has 7 valence electrons. It uses seven in seven single bonds to F, so none are left over.
  2. Steric number = seven sigma bonds + no lone pairs = 7, so I is sp³d³ hybridised.
  3. Seven electron pairs point to the corners of a pentagonal bipyramid (pentagonal bipyramidal electron geometry). With no lone pairs the atoms take the same shape: pentagonal bipyramidal.
  4. All the bond pairs repel each other equally, so the angle is the ideal 72° and 90°.
  5. The bond dipoles cancel in the symmetric pentagonal bipyramidal shape, so IF₇ is non-polar.

Lewis structure

56 valence electrons
IFFFFFFF

Formal charges: none

Working

Why this hybridisation and shape

  1. I has 7 valence electrons. It uses seven in seven single bonds to F, so none are left over.
  2. Steric number = seven sigma bonds + no lone pairs = 7, so I is sp³d³ hybridised.
  3. Seven electron pairs point to the corners of a pentagonal bipyramid (pentagonal bipyramidal electron geometry). With no lone pairs the atoms take the same shape: pentagonal bipyramidal.
  4. All the bond pairs repel each other equally, so the angle is the ideal 72° and 90°.
  5. The bond dipoles cancel in the symmetric pentagonal bipyramidal shape, so IF₇ is non-polar.

Class 11, Chapter 4 Chemical Bonding and Molecular Structure.

Questions

Hybridisation of IF7: quick answers

What is the hybridisation of IF7?

I has 7 valence electrons. It uses seven in seven single bonds to F, so none are left over. Steric number = seven sigma bonds + no lone pairs = 7, so I is sp³d³ hybridised.

What is the shape of IF7 and its bond angle?

Pentagonal bipyramidal, with a bond angle of 72 degrees and 90 degrees. Seven electron pairs point to the corners of a pentagonal bipyramid (pentagonal bipyramidal electron geometry). With no lone pairs the atoms take the same shape: pentagonal bipyramidal. All the bond pairs repel each other equally, so the angle is the ideal 72° and 90°.

Is IF7 polar or non-polar?

Non-polar. The bond dipoles cancel in the symmetric pentagonal bipyramidal shape, so IF₇ is non-polar.

Try any molecule