The Chlorine tribromide Lewis structure is Cl–Br single bond, Cl–Br single bond and Cl–Br single bond; the central Cl has 5 electron domains (2 lone pairs), giving a trigonal bipyramidal electron-domain arrangement and a T-shaped molecular geometry with a ≈87.5° bond angle. Cl is best described as sp3d-hybridized, and Chlorine tribromide is polar because the T-shaped shape (and/or unequal terminal atoms) prevents cancellation of the bond dipoles.
Figure 1: Lewis Structure of Chlorine tribromide (Br3Cl)
| Chemical Formula | Br3Cl |
| CAS Number | 13986-77-1 |
| Total Valence Electrons | 28 |
| Lewis Structure | Cl–Br single bond, Cl–Br single bond and Cl–Br single bond |
| Electron-Domain Geometry | trigonal bipyramidal |
| Molecular Geometry | T-shaped |
| Hybridization Model | sp3d (central Cl) |
| Bond Angle | ≈87.5° |
| Polarity | Polar molecule |
This organic compound is used as a solvent, intermediate or specialty reagent in fine-chemical, pharmaceutical and materials synthesis; specify grade and impurity profile when sourcing.
To draw the Chlorine tribromide Lewis structure we first count the total valence electrons. Br3Cl contains 3×7 (Br) + 7 (Cl); the net charge of 0 gives a total of 28 valence electrons to place.
The central atom is Cl. 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 = 3×7 (Br) + 7 (Cl) = 28 electrons.
Place Cl 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: Cl–Br single bond, Cl–Br single bond and Cl–Br single bond; 2 lone pairs on Cl.
Counting bonding and nonbonding electrons around Cl therefore satisfies the octet/expanded-octet requirement for the drawn structure.
VSEPR theory states that the 5 electron domains around Cl arrange to minimize mutual repulsion, giving an trigonal bipyramidal 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 T-shaped; the Cl bond angle is set to ≈87.5° 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 Cl, 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, Cl uses sp3d hybrid orbitals to form the 5 equivalent electron-domain directions (3 bonding + 2 lone pair).
Formal charge on central Cl = V − N − ½B = 7 − 4 − ½×6 = 0. The preferred Lewis structure carries zero formal charge on the central atom (and on the terminals), so it is the dominant contributor.
Chlorine tribromide is polar. The T-shaped shape prevents cancellation of the bond dipoles. The bond dipoles do not cancel, leaving a net molecular dipole, which strongly influences solvation behavior and intermolecular interactions.
The decisive structural fact is not simply that the individual bonds are polar; it is whether molecular symmetry allows their vector sum to vanish. In Chlorine tribromide the T-shaped arrangement prevents cancellation, so a permanent dipole remains.
Interpretation consistent with standard VSEPR / molecular-geometry references.This polarity profile underpins its behavior as a solvent, reactant or process intermediate; when sourcing, specify grade and container compatibility.
| Species | Formula | Central Atom | Electron Domains | Molecular Geometry | Polarity |
|---|---|---|---|---|---|
| Chlorine tribromide | Br3Cl | Cl | 5 | T-shaped | Polar |
| Hydrogen chloride | HCl | Cl | 4 | linear (diatomic) | Polar |
| Chlorine | Cl2 | Cl | 4 | linear (diatomic) | Nonpolar |
| Chlorine trifluoride | ClF3 | Cl | 5 | T-shaped | Polar |
| Chlorine pentafluoride | ClF5 | Cl | 6 | square pyramidal | Polar |
| Chlorate | ClO3 | Cl | 4 | trigonal pyramidal | Polar |
Chlorine tribromide is polar. Its T-shaped geometry (and/or unequal terminal atoms) stops the bond dipoles from cancelling.
Cl–Br single bond, Cl–Br single bond and Cl–Br single bond; 2 lone pairs on Cl. It uses all 28 valence electrons and the preferred structure carries zero formal charge on the central atom.
The Cl angle is about ≈87.5°. Lone-pair repulsion compresses the angle from the ideal trigonal bipyramidal value.
The conventional model is sp3d. Chlorine tribromide has 5 electron domains around the central Cl.
The CAS number is 13986-77-1. PubChem and NIST identify this with Br3Cl; 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 13986-77-1 identifies the substance, not a universal purity specification.
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