Title: curly arrows
Long Title: IUPAC Gold Book - curly arrows
DOI: 10.1351/goldbook.08160
Status: current

Definition
Symbols for depicting the flow of electrons in a chemical reaction or to generate additional resonance forms.

Notes
1) The tail of the curly arrow shows where an electron pair originates, and the head of the curly arrow shows where the electron pair goes.
2) Single-headed curly arrows are used to depict the flow of unpaired electrons.

Example


Related Terms
- electron pushing: https://goldbook.iupac.org//terms/view/08166
- resonance forms: https://goldbook.iupac.org//terms/view/08205

Source
- PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 395 (https://doi.org/10.1515/pac-2018-1010)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08160/html
- json: https://goldbook.iupac.org/terms/view/08160/json
- xml: https://goldbook.iupac.org/terms/view/08160/xml

Citation: Citation: 'curly arrows' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08160
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-06-28T11:22:35+00:00