The Iodine tetrafluoride ion Lewis structure is I–F single bond, I–F single bond, I–F single bond and I–F single bond; the central I has 6 electron domains (2 lone pairs), giving a octahedral electron-domain arrangement and a square planar molecular geometry with a 90° bond angle. I is best described as sp3d2-hybridized, and Iodine tetrafluoride ion is nonpolar because the bond dipoles cancel by molecular symmetry.
Figure 1: Lewis Structure of Iodine tetrafluoride ion (F4I)
| Chemical Formula | F4I |
| CAS Number | 13780-58-0 |
| Net Charge | -1 |
| Total Valence Electrons | 36 |
| Lewis Structure | I–F single bond, I–F single bond, I–F single bond and I–F single bond |
| Electron-Domain Geometry | octahedral |
| Molecular Geometry | square planar |
| Hybridization Model | sp3d2 (central I) |
| Bond Angle | 90° |
| Polarity | Nonpolar molecule |
In aqueous and process chemistry, F4I exists as the anion Iodine tetrafluoride ion ion. It is encountered as a counterion and a controlled source of I in salts, buffers, electrochemistry and analytical protocols, and as a reactant in syntheses that require a defined equivalent of I-containing material.
To draw the Iodine tetrafluoride ion Lewis structure we first count the total valence electrons. F4I contains 4×7 (F) + 7 (I) − 1 (net anion); the net charge of -1 gives a total of 36 valence electrons to place.
The central atom is I. It is the least electronegative atom capable of forming multiple bonds and is surrounded by the more electronegative terminal atom(s); hydrogen, when present, always occupies a terminal position. Electronegativity considerations place the electron density toward the terminal atom(s).
Total valence electrons = 4×7 (F) + 7 (I) − 1 (net anion) = 36 electrons.
Place I at the center and connect each surrounding atom with a single bond, complete octets on the terminal atoms, and place any remaining electrons on the central atom. The resulting electron distribution is: I–F single bond, I–F single bond, I–F single bond and I–F single bond; 2 lone pairs on I.
Counting bonding and nonbonding electrons around I therefore satisfies the octet/expanded-octet requirement for the drawn structure.
VSEPR theory states that the 6 electron domains around I arrange to minimize mutual repulsion, giving an octahedral electron-domain geometry.
Because 2 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is square planar; the I bond angle is set to 90° rather than the ideal value for the electron-domain geometry.
A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 2 lone pair(s) on I, the lone-pair domains occupy positions that minimize overall repulsion while pushing the bonding domains (and therefore the bonded atoms) closer together.
In the conventional localized-bond model, I uses sp3d2 hybrid orbitals to form the 6 equivalent electron-domain directions (4 bonding + 2 lone pair).
Formal charge on central I = V − N − ½B = 7 − 4 − ½×8 = -1. The nonzero formal charge is distributed by resonance / charge separation; the drawn structure is the lowest-energy contributor.
Iodine tetrafluoride ion is nonpolar. Although individual I–terminal bonds are polar when the atoms differ in electronegativity, the square planar geometry makes their vector sum zero, so there is no net molecular dipole.
A common misconception is that polar bonds guarantee a polar molecule. Iodine tetrafluoride ion shows the opposite: identical bond dipoles arranged with square planar symmetry cancel exactly, yielding a nonpolar species.
Interpretation consistent with standard VSEPR / molecular-geometry references.Its nonpolar character governs solvation and intermolecular behavior; specify grade and handling when sourcing.
| Species | Formula | Central Atom | Electron Domains | Molecular Geometry | Polarity |
|---|---|---|---|---|---|
| Iodine tetrafluoride ion | F4I | I | 6 | square planar | Nonpolar |
| Iodine trifluoride | IF3 | I | 5 | T-shaped | Polar |
| Iodine pentafluoride | IF5 | I | 6 | square pyramidal | Polar |
| Iodine heptafluoride | IF7 | I | 7 | pentagonal bipyramidal | Nonpolar |
| Iodine | I2 | I | 4 | linear (diatomic) | Nonpolar |
| Hydrogen iodide | HI | I | 4 | linear (diatomic) | Polar |
Iodine tetrafluoride ion is nonpolar. Its square planar symmetry cancels the bond dipoles exactly.
I–F single bond, I–F single bond, I–F single bond and I–F single bond; 2 lone pairs on I. It uses all 36 valence electrons and the preferred structure carries a formal charge of -1 on the central atom.
The I angle is about 90°. Lone-pair repulsion compresses the angle from the ideal octahedral value.
The conventional model is sp3d2. Iodine tetrafluoride ion has 6 electron domains around the central I.
The CAS number is 13780-58-0. PubChem and NIST identify this with F4I; use it to locate suppliers and database records.
Technical scope: Lewis structures, VSEPR and hybridization are model-based descriptions for chemical communication and structure prediction; actual molecular electronic structure is more accurately represented by molecular-orbital and quantum-chemical methods. Commercial grades vary substantially by supplier and intended use; CAS 13780-58-0 identifies the substance, not a universal purity specification.
![]() |
![]() |