In this article we will get to know about SNF3 lewis structure and the facts around this topic.
SNF3, thiazyl triflouride is a chemical compound of nitrogen, sulphur, and flourine. It is a stable, colorless compound with tetrahedral geometry. It is a important precursor of sulphur nitrogen compound.
How to draw SNF3 lewis structure?
Lewis structure of a molecule is drawn to understand the geometry or the structure of a molecule. To draw the lewis structure of a molecule, the electrons present in the outermost shell or the valence electrons are considered. All other electrons are well protected. The electrons in lewis structure is mainly represented as dots called lewis symbols. The structures drawn by using this symbols are called lewis dot structures.
For drawing the lewis structure of any molecule we have to know certain rules. They are
- At first one should count all the valence electrons of all the atoms present in the molecule.
- In the next step we need to check the number of different atoms present in the molecule.When there is more than one atoms are present in a molecule, the least electronegative atom should be taken as the central atom and all the remaining atoms are drawn around the central atom.
- In this step draw a single bonds from the central atom to all the surrounding atoms.
- Complete the octet with the remaining electrons for the outer atoms.
- In the final step complete the octet of the central atom with remaining electrons or making pi bonds by taking the electrons from the other atoms.
Based on this rules lets draw the lewis structure of SNF3 or Thiazyl trifluoride.
- The total number of valence electrons in SNF3 is
6 + 5 + (7 * 3) = 32
So 32 valence electrons are present in SNF3 molecule.
- Here in thiazyl trifluoride one nitrogen, three fluorine atoms and one sulphur is present. Among these atoms sulphur is the least electronegative atom so that can be taken as the central atom of the molecule. Considering sulphur as the central atom all the remaining atoms are drawn around sulphur.
N S F
In the third step single bonds are drawn from sulphur to three fluorine and one nitrogen atom present. Here two pi bonds are formed between nitrogen and sulphur.
So the total number of electrons involved in bond formation of SNF3 is 12. So the balance valence electrons present here is 20.
The remaining 20 electrons are arranged around the atom in such a way that they complete their octet.
SNF3 lewis structure shape
The shape of the thiazyl fluoride molecule can be found out from its lewis structure. The geometry of the molecule mainly depends upon the number of sigma bonds made and the lone pairs of electrons present around the central atom of a molecule. Here there are the central atom sulphur forms 6 bonds in which 4 bonds are sigma and the 2 bonds are pi bonds.
Since there is no lone pair seen around the central atom we consider only the four sigma bonds. Due to presence of 4 sigma bonds SNF3 molecule has a tetrahedral shape. The bond length of S-F and S-N is found to be 155.2 pm and 141.6 pm respectively. The bond angle of F-S-F is 940.
SNF3 lewis structure formal charges
The formal charge of each atom in any molecule can be easily found out through a simple equation.
Formal charge of an atom = No. of valence electrons – No. of dots or electrons – No.of bonds formed.
Lets calculate the formal charge of each and every atom in SNF3
Formal charge of sulphur = 6 -0 – 6
Formal charge of nitrogen = 5 – 2 – 3
Formal charge of fluorine = 7 – 6 -1
So the formal charges of sulphur, fluorine and nitrogen is found to be 0 in SNF3.
SNF3 lewis structure Lone pair
Lone pair of electron present in any atom in a molecule can be determined through a simple equation.
Lone pair of electron in any atom = (valence electrons – No. of electrons shared by the atom) / 2
Number of lone pairs in sulphur = (6 -6) / 2
Number of electron pairs in nitrogen = (5 -3) / 2
Number of lone pairs present in fluorine = (7 -1) / 2
Since there are 3 fluorine atoms present then the total number of lone pairs are 9.
So the total number of lone pairs present in the SNF3 molecule is 10.
SNF3 molecule has sp3 hybridisation. Here the central atom is Sulphur.
The electronic configuration of sulphur in
ground state is 16S 1s2 2s2 2p6 3s2 3p4
Excited state 1s2 2s2 2p6 3s1 3p3 4s1 3d1
Here the one 3s and three 3p orbitals of sulphur overlapps with the 2p orbitals of fluorine and one of the 2p orbital of nitrogen to form sp3 hybridisation. The remaining 2 electrons in 4s and 3d orbitals of sulphur overlapps laterally with the 2p orbitals of nitrogen to form pi bond. So SNF3 molecule has tetrahedral geometry with bond angle 1090.
According to VSEPR ( Valence shell electron pair repulsion) theory, electrons are arranged around the central atom of a molecule in such a way to minimise the repulsion between the electron pairs. The geometry of a molecule, bond angle, bond length can also be understood from the number of bond pairs and lone pairs present around the central atom of a molecule.
The pi bond doesn’t have any role in the determination of geometry of a molecule. In SNF3 molecule the central atom is sulphur with no lone pair and 4 bond pairs indicates that the molecule undergo sp3 hybridisation.
SNF3 lewis structure resonance
Resonance is the way of representation of electrons around any atom in more than one way in its lewis structure. Due to this phenomena one molecule can have more than one lewis structure. Such structures are named as resonance hybrids. As the number of resonance hybrids increases the molecule will be that much stable.
Resonance only given by double bonded or unsaturated compounds. Because resonance is actually the delocalisation of electrons. Since sigma bonds are more strong and will never undergo resonance. But pi bonds can do so. Here there are two pi bonds present between the nitrogen and sulphur can give the different resonating structures or resonance hybrids.
SNF3 lewis structure octet rule
Octet rule states that when an element forms chemical bond in such a way that the number of valence electrons present in its outer most shell should be 8. Here in SNF3 also each of the atom obeys the octet rule. All the 3 fluorine, 1 nitrogen and sulphur atom’s valance shell contains exact 8 electrons. So the molecule SNF3 strictly obeys the octet rule.
SNF3 is Polar or Non polar
SNF3 molecule is polar in nature.The atoms present in SNF3 molecule is sulphur, nitrogen, and fluorine. There is 3 S-F bonds and one S-N bond. Fluorine is more electronegative compared to nitrogen. So the polarity of S-F bond will be greater than polarity of S-F bond.