Newman projection

A two-dimensional drawing of a molecule viewed along a carbon–carbon bond, showing the relative positions of groups attached to its two atoms. It makes bond rotation and conformational differences easy to compare.

Dihedral angle: The angle between two planes defined by four atoms connected in sequence. It measures the rotation around the viewed carbon–carbon bond.
Skeletal formula: A line-angle drawing of an organic molecule in which carbon atoms and most attached hydrogens are implicit. It is often the starting drawing converted into a Newman projection.
Conformational isomerism: Isomerism arising from different spatial arrangements interconverted by rotation around single bonds. Newman projections display the conformers being compared.
Fischer projection: A two-dimensional convention for representing stereochemistry, especially in molecules with a chain of stereocenters. It encodes stereochemical arrangement rather than viewing along one bond.
Staggered conformation: A conformation in which groups on adjacent atoms are offset rather than aligned when viewed along their connecting bond. Its offset bonds appear separated in a Newman projection.
Carbon–carbon bond: A covalent bond joining two carbon atoms. The projection is defined by looking directly along this bond.
Butane: A four-carbon alkane whose central carbon–carbon bond permits several distinct conformations. Its central bond gives the classic comparison of anti, gauche, and eclipsed forms.
Sawhorse projection: A perspective drawing of a molecule that shows a carbon–carbon bond and its attached groups obliquely. It depicts the same bond rotation without looking straight down the bond.
Eclipsed conformation: A conformation in which bonds on adjacent atoms align when viewed along their connecting bond. Aligned groups make the eclipsed arrangement visible in the projection.
Tetrahedral molecular geometry: A three-dimensional arrangement with four substituents directed toward the corners of a tetrahedron. The substituents around each carbon are arranged approximately tetrahedrally.

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Open-chain compoundRelated: It represents rotations and steric interactions within an open-chain molecule.