P

Polar Bond

Polar bond: δ+ — δ−; Δχ > 0.4; partial charges
Quick Reference
Formula / NotationPolar bond: δ+ — δ−; Δχ > 0.4; partial charges
Also Known AsPolar covalent bond, dipolar bond, δ+−δ− bond

What is Polar Bond?

A covalent bond between two atoms of different electronegativities in which electrons are unequally shared. The more electronegative atom carries a partial negative charge (δ-), and the less electronegative atom carries a partial positive charge (δ+). Water's O-H bonds are polar.

Formula & Notation

Polar bond: δ+ — δ−; Δχ > 0.4; partial charges

Other Names / Synonyms: Polar covalent bond, dipolar bond, δ+−δ− bond

Properties & Characteristics

A polar bond is a covalent bond in which the electron density is unequally shared between the two bonded atoms due to a difference in their electronegativities (typically ΔEN > 0.4-0.5). The more electronegative atom carries a partial negative charge (δ−) and the less electronegative atom carries a partial positive charge (δ+). Polar bonds give rise to bond dipole moments. When bond dipoles do not cancel, the molecule has a net dipole moment (is polar).

Uses & Applications

Polar bonds determine: molecular polarity (affects solubility, boiling point, intermolecular forces), reactivity (polar bonds are susceptible to nucleophilic/electrophilic attack), spectroscopy (IR-active vibrations change dipole moment), and drug-receptor interactions (polar groups form hydrogen bonds and ion-dipole interactions with biological targets).

Safety Information

Highly polar bonds (H-F, O-H) create strong hydrogen bonding, explaining why HF and H₂SO₄ are more viscous and corrosive than expected. Polar bonds in solvent molecules determine their ability to stabilise charge intermediates — polar aprotic solvents (DMSO, DMF) enhance nucleophile reactivity and may increase exposure to toxic nucleophilic intermediates.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Polar Bond
Formula Polar bond: δ+ — δ−; Δχ > 0.4; partial charges
Synonyms Polar covalent bond, dipolar bond, δ+−δ− bond

Frequently Asked Questions

A covalent bond between two atoms of different electronegativities in which electrons are unequally shared. The more electronegative atom carries a partial negative charge (δ-), and the less electronegative atom carries a partial positive charge (δ+). Water's O-H bonds are polar.

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