Tin tetrachloride Lewis Structure

Tin tetrachloride Lewis Structure: Cl₄Sn Lewis Structure, tetrahedral Geometry, sp3 Hybridization & Polarity

Tin tetrachloride Key Facts

The Tin tetrachloride Lewis structure is Sn–Cl single bond, Sn–Cl single bond, Sn–Cl single bond and Sn–Cl single bond; the central Sn has 4 electron domains (0 lone pairs), giving a tetrahedral electron-domain arrangement and a tetrahedral molecular geometry with a 109.5° bond angle. Sn is best described as sp3-hybridized, and Tin tetrachloride is nonpolar because the bond dipoles cancel by molecular symmetry.

Figure 1: Lewis Structure of Tin tetrachloride (Cl₄Sn)

Chemical Formula	Cl₄Sn
CAS Number	7646-78-8
Total Valence Electrons	32
Lewis Structure	Sn–Cl single bond, Sn–Cl single bond, Sn–Cl single bond and Sn–Cl single bond
Electron-Domain Geometry	tetrahedral
Molecular Geometry	tetrahedral
Hybridization Model	sp3 (central Sn)
Bond Angle	109.5°
Polarity	Nonpolar molecule

PubChem (CID 24287) and NIST list Tin tetrachloride as Cl ₄Sn with CAS 7646-78-8; molecular weight ≈ 260.5 g/mol. View CAS 7646-78-8 dictionary details on Guidechem →

Applications of Tin tetrachloride (CAS 7646-78-8)

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.

Solvent / Reagent Medium for reactions, extraction or formulation.

Intermediate Building block for downstream derivatives.

Specialty Use Targeted role in pharma/fragrance/materials.

Procurement Note "Tin tetrachloride" is supplied in multiple commercial grades and package sizes. Specify purity, grade, moisture/impurity limits, package (cylinder, drum or bulk) and intended process, and use CAS 7646-78-8 as the primary identifier when screening suppliers; always confirm regional availability and safety documentation (SDS).

Step 1 - Valence Electrons & Central Atom

To draw the Tin tetrachloride Lewis structure we first count the total valence electrons. Cl₄Sn contains 4×7 (Cl) + 4 (Sn); the net charge of 0 gives a total of 32 valence electrons to place.

The central atom is Sn. 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).

Valence-electron count

Total valence electrons = 4×7 (Cl) + 4 (Sn) = 32 electrons.

Step 2 - Lewis Structure & Electron Distribution

Place Sn 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: Sn–Cl single bond, Sn–Cl single bond, Sn–Cl single bond and Sn–Cl single bond; no lone pairs on Sn.

Counting bonding and nonbonding electrons around Sn therefore satisfies the octet/expanded-octet requirement for the drawn structure.

Sn–Cl Sn–Cl Sn–Cl Sn–Cl

Sn: 0 lone pairs, 4 bonding domains

4 bonding domains + 0 lone pairs = 4 electron domains

Octet Rule: Why Sn Has Eight Electrons Sn forms 4 bond(s) and retains 0 nonbonding electron(s), reaching an octet. No expanded octet is required for this second-row (or octet-satisfying) central atom.

Step 3 - VSEPR Theory & Geometry

VSEPR theory states that the 4 electron domains around Sn arrange to minimize mutual repulsion, giving an tetrahedral electron-domain geometry.

Because 0 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is tetrahedral; the Sn bond angle is set to 109.5° rather than the ideal value for the electron-domain geometry.

Repulsion hierarchy

A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 0 lone pair(s) on Sn, the lone-pair domains occupy positions that minimize overall repulsion while pushing the bonding domains (and therefore the bonded atoms) closer together.

Hybridization & Formal Charge

In the conventional localized-bond model, Sn uses sp3 hybrid orbitals to form the 4 equivalent electron-domain directions (4 bonding + 0 lone pair).

Formal-charge check

Formal charge on central Sn = V − N − ½B = 4 − 0 − ½×8 = 0. The preferred Lewis structure carries zero formal charge on the central atom (and on the terminals), so it is the dominant contributor.

Modeling Note Modeling Note: sp3 is a compact model for the 4 electron-domain directions around Sn; full quantum-chemical treatments use molecular orbitals.

Is Tin tetrachloride Polar or Nonpolar?

Tin tetrachloride is nonpolar. Although individual Sn–terminal bonds are polar when the atoms differ in electronegativity, the tetrahedral geometry makes their vector sum zero, so there is no net molecular dipole.

Expert Quote — Structural Chemistry Perspective

A common misconception is that polar bonds guarantee a polar molecule. Tin tetrachloride shows the opposite: identical bond dipoles arranged with tetrahedral 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.

Structural Comparison Table

Species	Formula	Central Atom	Electron Domains	Molecular Geometry	Polarity
Tin tetrachloride	Cl₄Sn	Sn	4	tetrahedral	Nonpolar
Carbon dioxide	CO₂	C	2	linear	Nonpolar
Carbon monoxide	CO	C	2	linear (diatomic)	Polar
Carbon disulfide	CS₂	C	2	linear	Nonpolar

Practice question Starting from the 32 valence electrons of Cl₄Sn, draw the Lewis structure and confirm the central Sn atom is sp3-hybridized with tetrahedral geometry. What happens to the bond angle if one terminal atom is replaced by a more electronegative substituent?

Looking for industrial bulk or specified-grade supplies of Tin tetrachloride (CAS 7646-78-8)? Browse Supplier on Guidechem →

FAQs

Is Cl₄Sn polar or nonpolar?

Tin tetrachloride is nonpolar. Its tetrahedral symmetry cancels the bond dipoles exactly.

What is the Lewis structure of Tin tetrachloride?

Sn–Cl single bond, Sn–Cl single bond, Sn–Cl single bond and Sn–Cl single bond; no lone pairs on Sn. It uses all 32 valence electrons and the preferred structure carries zero formal charge on the central atom.

What is the bond angle in Tin tetrachloride?

The Sn angle is about 109.5°. Lone-pair repulsion compresses the angle from the ideal tetrahedral value.

What is the hybridization of Sn in Tin tetrachloride?

The conventional model is sp3. Tin tetrachloride has 4 electron domains around the central Sn.

What is the CAS number of Tin tetrachloride?

The CAS number is 7646-78-8. PubChem (CID 24287) and NIST identify this with Cl₄Sn; use it to locate suppliers and database records.

References

PubChem CID 24287, Tin tetrachloride. Molecular formula, CAS number, molecular weight and chemical identity.
NIST Chemistry WebBook, SRD 69, Tin tetrachloride. Formula, CAS Registry Number and thermochemical / spectroscopic data.
IUPAC Gold Book. Definitions for "lone pair", "VSEPR", "hybridization" and "formal charge".
Atkins, P. & de Paula, J., Physical Chemistry. VSEPR, molecular geometry and dipole moments.
Guidechem supplier & dictionary records. Commercial sourcing and CAS-linked property pages for Tin tetrachloride (CAS 7646-78-8).

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 7646-78-8 identifies the substance, not a universal purity specification.

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Tin tetrachloride Lewis Structure