Organic Chemistry: Current Research
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Lewis Structure in Organic Chemistry

Sandhya Kille^{* *}Correspondence: Sandhya Kille, Department of Chemistry, Acharya Nagarjuna University, Guntur, Andhra Pradesh, India, Email:

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Lewis structures, also known as Lewis-dot diagrams, depict the bonding between atoms in a molecule and the molecule's lone pairs of electrons. In combination with hybrid orbitals, Lewis structures can be beneficial in forecasting molecular geometry. Multiple resonance forms of a molecule can exist, all of which are proper Lewis structures. The rules for accurately drawing out Lewis structures will be discussed in this section. All electron pairs are shown in the Lewis structure, which is a representation of molecular structure. A pair of dots next to an atom indicates lone electron pairs (unshared electron pairs). All electrons in a Lewis dot structure are represented by dots rather than lines.
It might be complex and difficult to write out Lewis structures at times. A compound can have numerous Lewis Structures that contribute to the overall shape of the compound, hence one Lewis structure may not be the same as the overall shape of the compound. But there are a few things to keep in mind before we get started. A dot is a representation of an electron. Two dots between the bound atoms or a line (Kekulé structures lines) denote a bond made up of two shared electrons. Two and three lines (pairs of electrons) are used to symbolise double and triple bonds, respectively. Lone pairs on an atom's outer rims are depicted by two dots.
The outer-shell electrons, also known as valence electrons, are represented in a Lewis structure. This is due to the fact that they are the ones who are involved in chemical reactions. Because all processes apply to every compound, the examples mentioned below may or may not be consistent for each step for the sake of providing multiple examples. We're now ready to get started.
Sketch out the compound's molecular backbone. Because we must choose one or more atoms to be the central connector to terminal (outside) atoms, this is perhaps the most difficult stage in drawing Lewis structures. In many organic compounds with Carbon as the central atom, the central atom is usually already known. The central atom, however, is the atom with the lowest electronegativity. Other issues, such as the octet rule, come into play, which will be explained in this section. A periodic table of elements with electronegativity values for each element can be used to determine the electronegativity values of atoms.
As a result, the bonds can be represented by a line or a pair of electrons (two dots), and Lewis structures can be described as electron-dot representations of molecules. It is relatively simple to interpret the structure once we understand this concept. Creating a suitable Lewis structure from a formula, on the other hand, is not as straightforward. When sketching a Lewis structure, there are a few factors to bear in mind. These include placing the atoms in the correct order in the molecule, calculating the number of electrons involved in bonding and non-bonding interactions, and keeping track of those electrons While hydrogen and the succeeding elements have few electrons, the elements below the second row of the periodic table have extremely complicated electron configurations, making chemical bonding difficult. Because the valence electrons produce the covalent bonds, Lewis proposed focusing just on them to make things easier and avoid any possible mistake.
Valence electrons are those in the outermost energy level (principal quantum number – n), as a reminder. Carbon, for example, has the electron configuration 1s^₂ 2s^₂ 2p² . The 2s² 2p²  four electrons in the second energy level, n=2, are among them. So, because carbon is in group 4, it contains four valence electrons, as do all the other elements.