SF4 Molecular Geometry - Science Education and Tutorials

Q: What is the molecular notation for SF4 molecule?

SF4 molecular notation is AX4N1

Drawing and predicting the SF4 molecular geometry is very easy. Here in this post, we described step by step method to construct SF4 molecular geometry.

Table of Contents

Key Points To Consider When drawing The SF4 Molecular Geometry

A three-step approach for drawing the SF4 molecular can be used. The first step is to sketch the molecular geometry of the SF4 molecule, to calculate the lone pairs of the electron in the central sulfur atom; the second step is to calculate the SF4 hybridization, and the third step is to give perfect notation for the SF4 molecular geometry.

The SF4 molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the SF4 molecule in a specific geometric manner. The geometry of the SF4 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory) and molecular hybridization theory, which states that molecules will choose the SF4 geometrical shape in which the electrons have from one another in the specific molecular structure.

Finally, you must add their bond polarities characteristics to compute the strength of the S-F bond (dipole moment properties of the SF4 molecular geometry). The sulfur-fluorine bonds in the sulfur tetrafluoride molecule(SF4), for example, are polarised toward the more electronegative value fluorine atom, and because all (S-F) bonds have the same size and polarity, their sum is non zero due to the SF4 molecule’s bond dipole moment, and the SF4 molecule is classified as a polar molecule.

The molecule of sulfur tetrafluoride (with bipyramidal trigonal shape SF4 molecular geometry) is tilted at 102 and 173 degrees. It has a difference in electronegativity values between fluorine and sulfur atoms, with fluorine’s pull the electron cloud being greater than sulfur’s. As a result, it has a permanent dipole moment in its molecular structure. The SF4 molecule has a dipole moment due to an unequal charge distribution of negative and positive charges.

Overview: SF4 electron and molecular geometry

According to the VSEPR theory, SF4 possesses a bipyramidal trigonal molecular geometry and SF4-like electron geometry. Because the center atom, sulfur, has four S-F bonds with the fluorine atoms surrounding it. The F-S-F bond generates 102 and 173 degrees in the bipyramidal trigonal molecular geometry. The SF4 molecule has a bipyramidal trigonal geometry shape because it contains four fluorine atoms.

There are four S-F bonds at the SF4 molecular geometry. After linking the four fluorine atoms in the bipyramidal trigonal form, it maintains the trigonal bipyramidal-like structure. In the SF4 molecular geometry, the S-F bonds have stayed in the four terminals of the trigonal bipyramidal molecule.

The center sulfur atom of SF4 has one lone pair of electrons, resulting in bipyramidal electron geometry. However, the molecular geometry of SF4 looks like a trigonal bipyramidal and one lone pair out of the plane. It’s the SF4 molecule’s asymmetrical geometry. As a result, the SF4 molecule is polar.

How to find SF4 molecular geometry and hybridization

Calculating lone pairs of electron on sulfur in the SF4 molecular geometry:

1.Determine the number of lone pairs on the core be an atom of the SF4 Lewis structure.
Because the lone pairs on sulfur are mostly responsible for the SF4 molecule geometry distortion, we need to calculate out how many there are on the central sulfur atom of the Lewis structure.

Use the formula below to find the lone pair on the sulfur atom of the SF4 molecule.
L.P(S) = V.E(S) – N.A(S-F)/2

Lone pair on the central sulfur atom = L.P(S)
The core central sulfur atom’s valence electron = V.E(S)
Number of S-Fbonds = N.A (S-F)
calculation for sulfur atom lone pair in SF4 molecule

For instance of SF4, the central atom, sulfur, has six electrons in its outermost valence shell and four S-F bond connections.

As a result of this, L.P(S) = (6 –4)/2=1

In the SF4 electron geometry structure, the lone pair on the central sulfur atom is one. It means there is one lone pair in the core sulfur atom. These lone pair on the central sulfur atom is responsible for the SF4 molecular geometry distortion.

If you imagine, these is no lone pair on sulfur atom of SF4 molecule. Then , no electronic repulsion of S-F bond pair and lone pair in the SF4. That gives stable trigonal bipyramidal geometry.

But in reality, SF4 molecule undergoes distortion in its geometry due to the lone pair of electron on the sulfur atom. This leads bipyramidal trigonal geometry for SF4 molecule.

Calculate the number of molecular hybridizations of SF4 molecule

What is SF4 hybrizidation? This is a very fundamental question in the field of molecular chemistry. All the molecules made by atoms. In chemistry, atoms are the fundamental particles. There are four different types of orbitals in chemistry. They are named as s, p, d, and f orbitals.

The entire periodic table arrangement are based on these orbital theory. Atoms in the periodic table are classified as follows:

s- block elements
p- block elements
d-block elements
f-block elements
Atoms are classified in the periodic table

SF4 molecule is made of one sulfur and four fluorine atoms. The sulfur atom has s, p, and d orbital. Fluorine comes as the first element in the periodic table. The fluorine atom has s and p arbitals.

When these atoms combine to form the SF4 molecule, its orbitals mixed and form unique molecular orbitals due to hybridization.

How do you find the SF4 molecule’s hybridization? We must now determine the molecular hybridization number of SF4.

The formula of SF4 molecular hybridization is as follows:
No. Hyb of SF4 = N.A(S-F bonds) + L.P(S)
No. Hy of SF4= the number of hybridizations of SF4
Number of S-F bonds = N.A (S-F bonds)
Lone pair on the central sulfur atom = L.P(S)
Calculation for hybridization number for SF4 molecule

In the SF4 molecule, sulfur is a core atom with four fluorine atoms connected to it and one lone pair. The number of SF4 hybridizations (No. Hyb of SF4) can then be estimated using the formula below.

No. Hyb of SF4= 4+1 =5

The SF4 molecule hybridization is five. The sp3d hybridization is formed when one S orbital, three p orbitals, and one d orbital join together to form a molecular orbital.

Molecular Geometry Notation for SF4 Molecule :

Determine the form of SF4 molecular geometry using VSEPR theory. The AXN technique is commonly used when the VSEPR theory is used to calculate the shape of the SF4 molecule.

The AXN notation of SF4 molecule is as follows:
The center sulfur atom in the SF4 molecule is denoted by the letter A.
The bound pairs (S-F) of electrons to the core sulfur atom are represented by X.
The lone pairs of electrons on the center sulfur atom are denoted by the letter N.
Notation for SF4 molecular geometry

We know that sulfur is the core atom, with four electron pairs bound (four S-F) and one lone pair. The general molecular geometry formula for SF4 is AX4N1.

According to the VSEPR theory, if the SF4 molecule has an AX4N1 generic formula, the molecular geometry and electron geometry will both be bipyramidal trigonal forms.

Name of Molecule	sulfur tetrafluoride
Chemical molecular formula	SF4
Molecular geometry of SF4	Bipyramidal trigonal
Electron geometry of SF4	Bipyramidal trigonal
Hybridization of SF4	sp3d
Bond angle (F-S-F)	102 º and 173º degree
Total Valence electron for SF4	34
The formal charge of SF4 on sulfur	0

Summary:

In this post, we discussed the method to construct SF4 molecular geometry, the method to find the lone pairs of electrons in the central sulfur atom, SF4 hybridization, and SF4 molecular notation. Need to remember that, if you follow the above-said method, you can construct the SF4 molecular structure very easily.