IUPAC - formal charge (08169)

formal charge

https://doi.org/10.1351/goldbook.08169

Quantity (omitted if zero) attached to each atom in a Lewis structure according to

Z_{f o r m a l} = N_{v a l e n c e} - N_{l o n e p a i r s} - ½ N_{b o n d s}

Examples: $CH_{2} = N^{+} = N^{-}$ , $H_{3} O^{+}$ , $(CH_{3})_{2} C = N - O^{-}$ , etc.

Note: This formalism assumes that electrons in bonds are shared equally, regardless of electronegativity.

Source:
PAC, 2022, 94, 353. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)) on page 421 [Terms] [Paper]

Citation: 'formal charge' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.08169 RIS BibTex EndNote

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formal charge