How to draw SF2 Lewis Structure? - Science Education and Tutorials

Q: What is the SF2 Lewis structure?

SF2 Lewis structure is dot representation

Q: What is the formal charge on the SF2 Lewis structure?

Zero charges on the SF2 molecular structure

The sulfur difluoride chemical formula is SF2. Drawing SF2 Lewis Structure is very easy to by using the following method. Here in this post, we described step by step method to construct SF2 Lewis Structure. The sulfur and fluorine elements come as the member of the oxygen and halogen family groups from the periodic table respectively. The valence electrons in sulfur and fluorine are six and seven respectively. The branch of sulfur halogen compound chemistry is used to make chemicals reagents for sulfonation reactions.

Table of Contents

Key Points To Consider When Drawing The SF2 Electron Dot Structure

A three-step approach for drawing the SF2 Lewis structure can be used. The first step is to sketch the Lewis structure of the SF2 molecule, to add valence electrons around the sulfur atom; the second step is to add valence electrons to the two fluorine atoms, and the final step is to combine the step1 and step2 to get the SF2 Lewis Structure.

The SF2 Lewis structure is a diagram that illustrates the number of valence electrons and bond electron pairs in the SF2 molecule. The geometry of the SF2 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which states that molecules will choose the SF2 geometrical shape in which the electrons have from one another.

Finally, you must add their bond polarities to compute the strength of the two S-F single bonds (dipole moment properties of the SF2 molecule). The sulfur-fluorine bonds in sulfur difluoride(SF2), for example, are polarised toward the more electronegative fluorine in SF2 molecule, and because both bonds have the same size and are located around two fluorine terminals of the tetrahedral or bent V-shaped with two lone pairs (in total four electrons) on the sulfur atom, their sum of dipole moment is nonzero due to the SF2 molecule’s bond dipole moment and more electron polarity to the fluorine atoms. Because each two S-F bonds polarity not canceled each other in the SF2 molecule due to the presence of two lone pairs of electrons. The sulfur difluoride(SF2) molecule is classified as a polar molecule.

The molecule of sulfur difluoride (with tetrahedral or bent V-shaped molecular geometry) is tilted, the bond angles between sulfur and fluorine are 98.3 degrees. It has a difference in electronegativity values between sulfur and fluorine atoms, with central sulfur’s pull being less than terminal fluorine’s in the SF2 molecule. But they not canceled each other due to the asymmetrical tetrahedral with two lone pairs in the molecular geometry of the SF2 molecule.

As a result, it has the nonzero dipole moment. The SF2 molecule has a nonzero dipole moment due to an unequal charge distribution of negative and positive charges. But both sulfur and fluorine atoms fall on the oxygen and halogen family groups in the periodic table respectively. The fluorine atom is a more electronegative value than sulfur in the SF2 molecule. The SF2 molecule has the net nonzero dipole moment in the ground state energy level.

SF2 molecule has two S-F single bonds. Its dipole moment in the ground state is totally different as compared with the excited state. If it absorbs light may be from visible or UV light. It undergoes pi to pi star and n to pi star transition from ground state energy level to excited state energy level. In the excited state energy level, the SF2 molecule shows a definite dipole moment. But it is very dynamics.

Molecules can be classified as polar or nonpolar. The molecule polar behaves in a different manner as compared to nonpolar.

Overview: SF2 Lewis Structure

The central atom is sulfur, which is bordered on two terminals with fluorine atoms( in tetrahedral geometry), and two lone pairs on the central sulfur atom in the tetrahedral molecular geometry. Sulfur has six outermost valence electrons, indicating that it possesses six electrons in its outermost shell, whereas fluorine also has seven valence electrons in its outermost shell. To complete the octet of the sulfur and fluorine atoms requires two and one valence electrons on each of their outermost shell respectively.

Two fluorine atoms establish covalent connections with the central sulfur atom as a result, leaving the sulfur atom with two lone pairs. There are two lone pairs of electrons on the sulfur central atom that resists the bond pairs of the two S-F bonds. According to VSEPR theory, the single S-F bond pairs polarity lead the SF2 molecule to take on the tetrahedral geometry structure.

The SF2 molecule’s two S-F bonds are arranged in symmetrical polarity order around the tetrahedral molecular geometry, giving rise to the SF2 molecular shape. The SF2 molecule has a tetrahedral or V-shaped bent molecular geometry because there is an electrical repulsion between the lone pairs of electrons in sulfur and two single bond pairs(S-F) of the SF2 molecule.

Lewis structure of SF2 has dot electron representative structure. Valence electrons of atoms undergo orbitals mixing in the chemical reactions, gives new types of molecular species of SF2. The molecule is nothing but a bundle of valence electrons from the atoms. But it is converted to bond pairs and lone pairs in the molecular structure.

Electronegative value Difference Calculation of SF2 Molecule:

Sulfur and fluorine Electronegative difference in SF2:

The sulfur atom has an electronegativity of 2.58, while fluorine has an electronegativity of 3.98 in the SF2 molecule. The difference in electronegativity of sulfur and fluorine can be estimated using the method below.

The electronegative value difference between sulfur and fluorine in SF2 molecule
Electronegativity value of sulfur = 2.58
Electronegativity value of fluorine= 3.98
Difference of electronegativity value between sulfur and fluorine in SF2 molecule = 3.98 – 2.58 = 1.40
Electronegativity difference between S-F bond calculation of SF2 molecule

The electronegative difference between sulfur and fluorine is greater than 0.5. This indicated the bond polarity moves near to polar nature. S-F bond polarity in the SF2 molecule is polar.

Because of this difference in electronegativity of sulfur and fluorine atoms, the SF2 molecule’s S-F bond becomes polar. The total net dipole moment of the SF2 molecule is nonzero due to the noncancellation of the bond dipole moment in the tetrahedral geometry. The electronegativity of an atom is the strength with which it may attract bound electron pairs to its side. The polarity of SF2 is discussed in our previous post.

As a result, the S-F bond’s dipole moment is high due to the polarization of the bonds and two lone pairs of electrons on sulfur, and all S-F bonds’ dipoles are arranged in the asymmetrical SF2 molecular geometry. The SF2 molecule has a nonzero net dipole moment.

The electron dot structure of the SF2 molecule is also known as the SF2 Lewis structure. It determines the number of outermost valence electrons as well as the electrons engaged in the SF2 molecule’s bond formation. The outermost valence electrons of the SF2 molecule must be understood while considering the Lewis structure of the molecule.

The sulfur atom is the middle element in SF2 molecular geometry, with six electrons in its outermost valence electron shell, whereas the fluorine atom has seven electrons in its outermost valence electron shell. The fluorine atom has seven valence electrons.

The SF2 has a total of 20 valence electrons as a result of the foregoing above-said reasoning. With the core central sulfur atom, the two terminals with two fluorine atoms form covalent bonds, leaving the sulfur atom with two lone pairs in the middle of tetrahedral geometry.

Because lone pairs on the terminal fluorine atoms create interaction with S-F bond pairs(but it is negligible in the ground state of the SF2 molecule). The bond angle of the F-S-F bond in the tetrahedral molecular geometry is approximately 98.3 degrees. This angle is less than the CH4 molecule bond angle. The S-F bond length is 159pm(picometer).

To sketch the SF2 Lewis structure by following these instructions:

Step-1: SF2 Lewis dot Structure by counting valence electrons on the sulfur atom

To calculate the valence electron of each atom in SF2, look for its periodic group from the periodic table. The oxygen and halogen group families, which are the 16th and 17th groups in the periodic table, are both made up of sulfur and fluorine atoms respectively. In their outermost shells, fluorine and sulfur have seven and six valence electrons respectively.

Calculate the total number of valence electrons in the SF2 molecule’s outermost valence shell. The first step is to determine how many electrons are in the SF2 Lewis structure’s outermost valence shell. An electron in an atom’s outermost shell is known as a valence electron. It is represented by dots in the SF2 Lewis diagram. The SF2 molecule’s core sulfur atom can be represented as follows:

Total outermost valence shell electron of sulfur atom in SF2 = 6
Total outermost valence shell electron of fluorine atom in SF2 = 7
The SF2 molecule has one central sulfur and two fluorine atoms. Then the total outermost valence shell electrons can be calculated as follows
∴ Total outermost valence shell electrons available for SF2 Lewis structure( dot structure) = 6+2*7= 20 valence electrons in SF2.
calculation of total valence electron of SF2 molecule

Choose the atom with the least electronegative value atom and insert it in the center of the molecular geometry of SF2. We’ll choose the least electronegative value atom in the SF2 molecule to place in the center of the SF2 Lewis structure diagram in this phase. The electronegativity value in periodic groups grows from left to right in the periodic table and drops from top to bottom.

The first step is to put six valence electrons around the sulfur atom as given in the figure.

Step-2: Lewis Structure of SF2 for counting valence electrons around the terminal fluorine atoms

As a result, sulfur is the second atom in the periodic table’s oxygen family group. Fluorine is the second member of the halogen family. The electronegative value of the fluorine atom is higher than that of the sulfur atom in the SF2 molecule. Furthermore, fluorine has a seven electrons limit since sulfur is the less electronegative element in the SF2 molecule.

In the SF2 Lewis structure diagram, the sulfur atom can be the center atom of the molecule. As a result, central sulfur in the SF2 Lewis structure, with all two fluorine atoms arranged in a tetrahedral geometry.

Add valence electrons around the fluorine atom, as given in the figure.

Step-3: Lewis dot Structure for SF2 generated from step-1 and step-2

Connect the exterior and core central atom of the SF2 molecule with two single S-F bonds. In this stage, use two fluorine atoms on the outside of the SF2 molecule to the central sulfur atom in the middle.

Count how many electrons from the outermost valence shell have been used in the SF2 structure so far. Each S-F single bond carries two electrons because each sulfur atom is connected to two fluorine atoms by two S-F single bonds. Bond pairings of S-F are what they’re called.

So, out of the total of 20 valence electrons available for the SF2 Lewis structure, we used four electrons for the SF2 molecule’s two S-F single bonds. The SF2 molecule has two lone pairs of electrons in the central sulfur atom.

Place the valence electrons in the S-F bond pairs starting with the core sulfur, two fluorine atoms in the SF2 molecule. In the SF2 Lewis structure diagram, we always begin by introducing valence electrons from the central sulfur atom(in step1). As a result, wrap around the central sulfur atom’s bond pair valence electrons first (see figure for step1).

The sulfur atom in the molecule gets only 8 electrons around its molecular structure. This central sulfur atom is octet stable. But it has two lone pairs. Sulfur compound(S8) is a yellowish solid in nature. when sulfur undergoes sublimation from solid-state to the gaseous state. But Sulfur is a very old anti-biotic for external uses.

Fluorine(F2) is in the gaseous state at normal temperature and pressure. It is used as a fluorinating agent in the field of organic chemistry. It is a highly corrosive gas. It is responsible for dry corrosion in the metal bodies. It is very reactive to bio-micro organisms. It is also used as a disinfectant in water treatment plants.

Sulfur requires 8 electrons in its outermost valence shell to complete the molecular octet stability, 4 electrons bond pairs in two S-F single bonds, and two lone pairs in the central sulfur atom. Then lone pairs of electrons on the fluorine atoms of the SF2 molecule are placed in a tetrahedral geometry. Sulfur already shares 8 electrons to the two S-F single bonds. Then place the valence electron in the fluorine atoms, it placed around seven electrons on each atom(step-2). 12 valence electrons placed around two fluorine atoms as lone pairs of electrons.

We’ve positioned 12 electrons around the two terminal fluorine atoms(step-3), which is represented by a dot, in the SF2 molecular structure above. The sulfur atom completes its molecular octet stability in the SF2 molecule because it possesses 4 electrons in its (two S-F single bonds) bond pairs with two fluorine in the outermost valence shell.

Count how many outermost valence shell electrons have been used so far using the SF2 Lewis structure. Two electron bond pairs are shown as dots in the SF2 chemical structure, whereas two single bonds each contain two electrons. The outermost valence shell electrons of the SF2 molecule(bond pairs) are 4 as a result of the calculation. The total valence electron in a sulfur atom is 8.

So far, we’ve used 20 of the SF2 Lewis structure’s total 20 outermost valence shell electrons. Two lone pairs of electrons on the sulfur atom in the tetrahedral geometry of the SF2 molecule.

Complete the middle sulfur atom stability and, if necessary, apply a covalent bond. The central sulfur atom undergoes octet stability(due to two single bond pairs of electrons).

The core atom in the SF2 Lewis structure is sulfur, which is bonded to the two fluorine atoms by single bonds (two S-F). With the help of two single bonds, it already shares 8 electrons. As a result, the sulfur follows the octet rule and has 8 electrons surrounding it on the two terminals of the SF2 molecule’s tetrahedral geometry.

How to calculate the formal charge on sulfur and fluorine atoms in SF2 Lewis Structure?

Calculating formal charge on the sulfur of SF2 molecule:

The formal charge on the SF2 molecule’s sulfur central atom often corresponds to the actual charge on that sulfur central atom. In the following computation, the formal charge will be calculated on the central sulfur atom of the SF2 Lewis dot structure.

To calculate the formal charge on the central sulfur atom of the SF2 molecule by using the following formula:
The formal charge on the sulfur atom of SF2 molecule= (V. E(S)– L.E(S) – 1/2(B.E))
V.E (S) = Valence electron in a sulfur atom of SF2 molecule
L.E(S) = Lone pairs of an electron in the sulfur atom of the SF2 molecule.
B.E = Bond pair electron in S atom of SF2 molecule
calculation of formal charge on sulfur atom in SF2 molecule

The sulfur core atom (two single bonds connected to two fluorine atoms ) of the SF2 molecule has six valence electrons, two lone pairs of electrons(four electrons), and 4 bonding pairing valence electrons. Put these values for the sulfur atom in the formula above.

Formal charge on sulfur atom of SF2 molecule = (6- 4-(4/2)) =0

In the Lewis structure of SF2, the formal charge on the central sulfur atom is zero.

Calculating formal charge on the fluorine atom of SF2 molecule:

The formal charge on the SF2 molecule’s fluorine terminal atoms often corresponds to the actual charge on that fluorine terminal atoms. In the following computation, the formal charge will be calculated on the terminal fluorine atom of the SF2 Lewis dot structure.

To calculate the formal charge on the terminal fluorine atom of the SF2 molecule by using the following formula:
The formal charge on the fluorine atom of SF2 molecule= (V. E(F)– L.E(F) – 1/2(B.E))
V.E (F) = Valence electron in a fluorine atom of SF2molecule
L.E(F) = Lone pairs of an electron in the fluorine atom of the SF2 molecule.
B.E = Bond pair electron in F atom of SF2 molecule
calculation of formal charge on fluorine atom in SF2 molecule

The fluorine terminal atoms of the SF2 molecule have seven valence electrons, three lone pairs of electrons(six electrons), and two bonding pairing valence electrons(single bond). Put these values for the fluorine atom in the formula above.

Formal charge on fluorine atom of SF2 molecule = (7- 6-(2/2)) =0

In the Lewis structure of SF2, the formal charge on the terminal fluorine atom is zero.

Summary:

In this post, we discussed the method to construct the SF2 Lewis structure. First, the valence electrons are placed around the sulfur atom. Second, place the valence electron on the fluorine atoms. Finally, when we combined the first and second steps. It gives SF2 Lewis structure. Need to remember that, if you follow the above-said method, you can construct molecular dot structure very easily.