Term: bisecting conformation (eclipsing conformation)
https://doi.org/10.1351/goldbook.B00673

Definition:
For a structure containing the grouping R3C–C(Y)=X (with identical or different groups R) the conformation in which the torsion angle is such that X is antiperiplanar to one of the groups R, and, in a Newman projection, the double bond C=X bisects one of the R–C–R angles. In this conformation the bond C–Y eclipses one of the C–R bonds. The other conformation, in which X is synperiplanar to one of the groups R, is called an eclipsing conformation. B00673.png

Related Terms:
1) conformation (http://doi.org/10.1351/goldbook.C01258).
2) torsion angle (http://doi.org/10.1351/goldbook.T06406).
3) antiperiplanar (http://doi.org/10.1351/goldbook.A00402).
4) newman projection (http://doi.org/10.1351/goldbook.N04134).
5) eclipses (http://doi.org/10.1351/goldbook.E01884).
6) synperiplanar (http://doi.org/10.1351/goldbook.S06231).
7) eclipsing conformation (http://doi.org/10.1351/goldbook.E01885).

Image: Not defined (https://goldbook.iupac.org/img/inline/B00673.png) 

Source: PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2201 (https://doi.org/10.1351/pac199668122193)

Citation: 'bisecting conformation (eclipsing conformation)' 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.B00673

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