COF2 is the molecular formula of Carbonyl fluoride which is a colorless and pungent gas to smell. It is highly toxic to human beings and is a strong irritant to the eyes, respiratory tract, skin, mucous membrane, and nose causing frostbite. It might interest you that carbonyl fluoride was used as one major chemical weapon during the First World War as it can easily penetrate the skin and can shut down the vital organs of the human body.
This gas has an unstable molecular structure which is prone to violent rupturing if exposed to heat for a longer period. The unstable behavior of carbonyl fluoride is not only dedicated to heat but to water as well. In the presence of water, carbonyl fluoride hydrolyses hydrogen fluoride and carbon dioxide.
Moreover, the carbonyl fluoride is prepared as a byproduct of the decomposition of fluorinated hydrocarbons, like tetrafluoromethane or trifluoromethanol during the thermal decomposition.
CF4 + H2O ——> COF2 + 2 HF
Another few methods of preparing carbonyl fluoride are reacting phosgene with the hydrogen fluoride and oxidation of carbon monoxide though it can produce carbon tetrafluoride.
CO + 2AgF2 —–> COF2 + 2AgF
What is the Lewis dot structure?
The Lewis dot structure is a diagrammatic representation showing how the electrons are participating in the bond formation forming a new compound with new chemical properties altogether. Only the electrons present in the outermost shell of an atom participates in the bond formation by either getting accepted or donated.
These electrons are present farthest from the nucleus of the atom because of which even with the slightest excitation, they undergo bond formation. Moreover, the Lewis structure also shows if a single, double or triple bond is forming between the atoms.
This bond formation is shown with the help of a line where one is used for the single bond, two for double, and three for the triple bond. Whereas, the Lewis diagram is drawn by using the symbol of the atom and valence electrons in pair around it.
COF2 Lewis Dot Structure
To determine the Lewis structure of carbonyl fluoride, it is first essential to study the same for the participating atoms, which are carbon and fluorine in this case.
The atomic number of carbon is 6, where its electronic configuration is 1s2 2s2 2p2. To achieve a stable state, the p shell needs to accommodate 6 valence electrons. So, the total number of valence electrons in carbon is 4.
On the other hand, the atomic number of fluorine is 9, where its electronic configuration is 1s2 2s2 2p5. Here comes an anomaly with fluorine as the valence electrons are also the ones available in the highest principal energy levels.
So, the total number of it can be calculated by summing up the valence electrons present in these highest principal energy levels, which are 2s and 2p in the case of fluorine. In accordance with this, the total number of valence electrons in fluorine is 7.
Lastly, the atomic number of oxygen is 8 where its electronic configuration is 1s2 2s2 2p4. By applying the same rule on the oxygen atom as that in fluorine, the valence electrons turn out to be 6 in an oxygen atom.
Now, let’s study the steps involved in drawing the Lewis dot structure of carbonyl fluoride:
Step 1: Search for the total number of valence electrons already available in a single carbonyl fluoride atom: It is 24 as 4 are coming from the carbon atom, 6 are coming from the oxygen atom and 7 are coming from each of the fluorine atoms.
Step 2: Search for how many more valence electrons are needed by one carbonyl fluoride atom:
It is 8 as 4 are needed by the carbon atom, 2 are needed by the oxygen atom and one valence electron is needed by each of the fluorine atoms.
Step 3: Look for the central atom in one carbonyl fluoride atom:
The atom present as the single entity is considered as the central atom which can be either carbon or oxygen for carbonyl fluoride. By logic, the central atom should be the one, that can form the maximum number of bonds with other atoms.
This means the atom having the least electronegativity value will be the central atom. The electronegativity value of oxygen and carbon are 3.44 and 2.55. So, the central atom will be the carbon atom.
Step 4: Find the type of bond-forming among the participating atoms of the carbonyl fluoride molecule: A shared covalent double bond will form between the oxygen and carbon atom while a single bond will form between each of the fluorine and carbon bond.
Step 5: Now assemble all the above-mentioned points and draw the Lewis dot diagram of carbonyl fluoride (COF2):
Molecular Geometry of Carbonyl Fluoride (COF2)
Molecular geometry is a 3D diagrammatic way of studying the structure of an atom. You can study the bond length, type, angle, and other geometrical entities with the help of molecular geometry.
Studying this comes after preparing the Lewis structure and can help with figuring out hybridization, polarity, and molecular orbital diagram of an atom.
Carbonyl fluoride (COF2) is a tetra-atomic molecule where the bond angle between the participating atoms is 120° which makes the molecular geometry trigonal planar.
COF2 is an interesting molecule where you might think even after having so many lone pairs of electrons, there is no distortion in the bond angle value at all.
It can be studied with the help of the Valence Shell Electron Pair Repulsion (VSEPR) theory that defines the reason for such anomaly carbonyl fluoride is showcasing.
There exist a balanced proportion of the number of bonds forming and lone pair of electrons which cancel out the effect of one another. Due to this, there exist a strong force of repulsion that can change the molecular geometry of the carbonyl fluoride.
If you see the lone pair of electrons on the fluorine and oxygen atoms are all canceling out the effect of one another so, the carbonyl fluoride molecule is exerting the ideal trigonal planar structure and behavior.
Hybridization in Carbonyl Fluoride (COF2)
Hybridization is the pictorial representation of how the bond formation is taking place between different atoms, where electrons are interacting by jumping from one energy level to another.
It is a mathematical process of mixing two or more atomic orbitals of the same atom to produce new ones completely different in the structure but of similar energy levels.
As the molecular geometry of carbonyl fluoride (COF2) is trigonal planar with the bond angle of 120° with no distortion from the ideal state, the hybridization of the central atom is sp2. It can be studied with the help of Valence Bond Theory (VBT), which confirms that sp2 hybridization is only possible when the molecular geometry is trigonal planar.
Here, the mixing of one s orbital and two p orbitals having similar energy, mix and overlaps to produce a new hybrid orbital of the same energy in comparison to the older ones. Here, all the three hybrid orbitals reside in the same region giving rise to a 120° bond angle.
Moreover, the new hybrid orbitals possess 33.33% characteristics of s shell and 66.66% characteristics of p shell.
Polarity in Carbonyl Fluoride (COF2)
Polarity is the behavior by which an atom either attracts or repels other nearby electrons. It occurs when separation of charges occurs within the molecule which produces two ends where one is positively charged while the other is negatively charged.
The polarity behavior is best determined with the help of electronegativity which decides how strongly the molecule will attract nearby electrons. The electronegativity value of carbon, oxygen, and fluorine are 2.55, 3.44, and 3.98.
If the difference between the electronegativity values is more than 0.4, the molecule is polar, which is the case of carbonyl fluoride.
Another way of looking at polarity in carbonyl fluoride is, the molecule has an overall net dipole moment because of the presence of a double bond and uneven pair of lone pair of electrons on the participating atoms.
Carbonyl fluoride (COF2) is a toxic and inflammable compound whose Lewis structure determines the presence of a double bond between the carbon and oxygen atoms and single bonds between the carbon and fluorine atoms.
Moreover, there exist many lone pairs which do not alter the molecular geometry but make the molecule polar. The molecular geometry of carbonyl fluoride is ideal trigonal planar with a bond angle of 120°. Whereas, the hybridization type again turns out to be the ideal shape which is sp2, vastly followed by all the trigonal planar shaped molecules.