Lone pair is a set of electrons present in an atom’s valence shell that did not participate in any bond-formation reaction. Since they refuse to bond with the other atoms, they are also called the non-bonding electrons. While drawing the molecules’ structure, the lone pair electrons on shown as dots (..) above the atom.
The condensed structural formula disguises the molecule's true vastness by revealing only the number of atoms present. What remains hidden from sight are the bond connections, the bond angles, and their three-dimensional arrangements, so what we observe is just the molecule's literal condensed form.
The arrangement of groups around a central atom creates its three-dimensional shape. And this shape affects how it interacts with other molecules or ions.
The interactions could be bonding - to form new bonds or nonbonding- affecting the physical properties of solubility, melting point, boiling point, polarity, and more.
| Lewis Base | Nucleophile | Lowry Bronsted Base |
|---|---|---|---|
Nature | Donates Electron Pair to any electron-deficient center. Nucleophiles and Lowry Bronsted bases are Lewis bases. |
Nucleophiles are electron-rich species that can donate a pair of electrons and form a new covalent bond with an electron-deficient counterpart called the electrophiles. That is why electrophiles are referred to as lovers of electrons.
The nucleophiles donate electrons as lone pairs, pie bonds, or sigma bonds.
Read- What are nucleophiles?
Organic chemistry reactions involve electron-transfer reactions, and many of them use reaction mechanisms to show how electrons flow. This electron flow is typically represented using a double-sided curly arrow.
Nucleophiles are electron-rich molecules and anions that donate an electron pair to the electron-deficient counterparts, the electrophiles, and form covalent bonds with them.
While nucleophiles donate two electrons in exchange for forming two-electron covalent bonds with the electrophiles, the negative charge due to the two electrons is not obvious in many instances. Neutral molecules like Benzene, water, and ammonia can act as nucleophiles.
A broad way to categorize nucleophiles is as charged or neutral (uncharged).
Free Radical | Lone Pair | Bond Pair |
|---|---|---|
Homolytic bond cleavage generates two free radical species. A free radical is an atom carrying an unpaired electron, denoted as A. (atom symbol A with a dot for an electron on the superscript). |
Dipole-dipole interactions occur in polar molecules where the difference in electronegativity between the combining atoms creates positive and negative dipoles. These opposite poles align and result in electrostatic attraction throughout the polar medium. So, naturally, the strength of the interaction would depend on Coulomb’s law - the higher the magnitude of the charges and the lesser the distance between those charges, the stronger the dipole-dipole attractive interaction.