--- title: "Conformation: Newman Projections and the Chair" description: "Molecules with the same connectivity still differ in shape from moment to moment, and the shapes are not equally likely. Reading a molecule along a bond, or as a puckered ring, shows which arrangement" canonical: https://lightmysky.com/learn/science/conformation-newman-projections-and-the-chair-mt_N0_QpGF7Av source: https://lightmysky.com/learn/science/conformation-newman-projections-and-the-chair-mt_N0_QpGF7Av.md retrieved: 2026-09-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Conformation: Newman Projections and the Chair Molecules with the same connectivity still differ in shape from moment to moment, and the shapes are not equally likely. Reading a molecule along a bond, or as a puckered ring, shows which arrangement it spends its time in. Subject: Science · Area: Chemistry · Ages 18 to 19 Page: https://lightmysky.com/learn/science/conformation-newman-projections-and-the-chair-mt_N0_QpGF7Av ## Ready when they can - Draws a Newman projection for a named bond and identifies staggered and eclipsed arrangements - Sketches a rotation energy profile for butane and labels anti and gauche minima - Draws a cyclohexane chair, converts between the two chairs and tracks which positions become axial - Predicts the favoured chair for a substituted ring and explains the preference from steric interaction ## Lesson: Twists, chairs, and favourite shapes Single bonds spin, so every chain samples many shapes. Freeze one view by sighting straight down a chosen bond: that is a Newman projection. Draw the near carbon as a dot and the far carbon as a circle, with three bonds fanning from each. Staggered forms spread the bonds out and rest in valleys, while eclipsed forms line them up and perch on peaks. Butane adds steric spice to the pattern. Its two methyl ends clash in the gauche form, where they sit side by side, and relax in the anti form, where they point opposite. Sketch the rotation profile as valleys for staggered and peaks for eclipsed, with anti the deepest valley. Label each valley and peak before you argue about any mechanism step. **Example.** Rings cannot twist freely, so cyclohexane puckers into a chair with corners alternating up and down. Each carbon then carries one axial slot pointing up or down and one equatorial slot pointing outward. A ring flip converts one chair into the other and swaps every axial with an equatorial. Bulky groups prefer equatorial slots, so methylcyclohexane spends its time in the chair with methyl pointing outward. **Tip.** Keep conformations and configurations apart. Twists interconvert in a flash, while cis trans forms locked by rings or double bonds are permanent. Your exam habit: draw both chairs, park the bulky group equatorial, and pick that chair as the favourite. **Recap.** Sight down the bond, rest staggered, park big groups equatorial, and never bottle a twist. ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Hybridisation, Conjugation and Delocalisation in Organic Molecules](https://lightmysky.com/learn/science/hybridisation-conjugation-and-delocalisation-in-organic-molecules-mt_Anv0MSQ4hq) - [pKa as a Predictive Tool in Organic Chemistry](https://lightmysky.com/learn/science/pka-as-a-predictive-tool-in-organic-chemistry-mt_fI03mNIC_m) ## Opens up - [Chirality, R and S Assignment and Optical Activity](https://lightmysky.com/learn/science/chirality-r-and-s-assignment-and-optical-activity-mt_-p-7uFBTDt) - [Molecular Mechanics: Force Fields and Conformational Searching](https://lightmysky.com/learn/science/molecular-mechanics-force-fields-and-conformational-searching-mt_s4C0T3zFlf) - [E1, E2 and E1cb: Three Ways to Lose Two Groups](https://lightmysky.com/learn/science/e1-e2-and-e1cb-three-ways-to-lose-two-groups-mt_vVq_xeZrKv)