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Chlorine trifluoride (ClF₃) Lewis structure

28 valence electrons, T-shaped

Cl F F F
ClF₃ as the Lewis Structure Generator draws it: lone pairs as dots.

Build ClF₃ step by step in the Lewis Structure Generator

What is the Lewis structure of ClF₃?

Chlorine trifluoride, ClF₃, has 28 valence electrons. Chlorine is the central atom, joined by three Cl−F single bonds. It carries two lone pairs on the central Cl and three on each F. Every formal charge is zero. Cl is AX₃E₂: T-shaped, with ideal bond angles of 90° and 180°, and the molecule is polar.

Valence electrons in ClF₃

Element Group Valence electrons Atoms Electrons
Chlorine 17 7 1 7
Fluorine 17 7 3 21
Total 28

In one line: 7 + 3 × 7 = 28. Each atom brings the valence electrons its group gives it.

How to draw the ClF₃ Lewis structure

  1. Count the valence electrons. Valence electrons: Cl 7 and each F 7. 7 + 3 × 7 = 28.
  2. Choose the central atom. Cl goes in the middle: Cl is the least electronegative atom other than H, χ 3.16 against 3.98 for F.
  3. Join the atoms with single bonds. Three single bonds use 6 electrons, leaving 28 − 6 = 22.
  4. Complete the outer atoms. Each outer atom takes enough lone pairs to reach eight: 3 F × 6 = 18, leaving 22 − 18 = 4.
  5. Put the rest on the central atom. The 4 left go on the central atom as two lone pairs on Cl, and Cl now has 10 electrons round it. That is more than eight, which an atom from period 3 on can hold.
  6. Make multiple bonds where needed. Every atom already has an octet or more, so no lone pair needs to become a bond.

Lone pairs and formal charges in ClF₃

Atom Number Bonds Lone pairs Electrons round it Formal charge, V − N − B/2
Cl (central) 1 three single bonds 2 10 7 − 4 − 3 = 0
F 3 one single bond 3 8 7 − 6 − 1 = 0

V is the atom’s valence electrons, N its nonbonding electrons and B its bonding electrons. The formal charges add up to 0, the molecule’s overall charge.

Shape and polarity of ClF₃

Central atom Cl
VSEPR class AX₃E₂
Electron geometry trigonal bipyramidal
Molecular geometry T-shaped
Ideal bond angles 90° and 180°
Measured bond angle 87.5°
Polarity, an estimate polar

The T shape leaves the bond dipoles unbalanced.

Cl has three σ bonds and two lone pairs, five electron domains in all, so its electron geometry is trigonal bipyramidal. Counting only the bonded atoms, the molecular geometry is T-shaped.

The VSEPR Molecular Geometry viewer turns the AX₃E₂ shape in 3D, lone pairs included.

The measured angle is the accepted experimental value the VSEPR viewer quotes for this molecule.

Work with ClF₃