Newman Projections on the ChemIllusion Canvas
The Newman projection tool lets organic chemistry students and teachers add editable conformational-analysis diagrams to the ChemIllusion canvas, pick butane presets, and change substituent labels without redrawing the figure.
Newman projections are one of the first places organic chemistry asks students to think in three dimensions while drawing in two. You are looking straight down a carbon-carbon bond, comparing the front carbon's substituents with the back carbon's substituents, and deciding whether a conformation is staggered, eclipsed, anti, or gauche.
That is hard enough without making students rebuild the same diagram every time they want to compare butane conformers or swap one substituent. The new ChemIllusion Newman projection tool treats the diagram as an editable chemistry object on the Generator canvas.
Pick a preset, or run a relaxed RDKit torsion scan on your own structure. Labels and face rotation stay editable after inserting.
Why Newman projections need a better tool
A Newman projection is not just a circle with six labels. The front bonds meet at the center. The back bonds emerge from the circle. Each label belongs to a specific front or back position, and the connecting atom in a substituent such as CH3 needs to sit on the bond line. If the label floats in the wrong place, the chemistry becomes harder to read.
Most drawing tools make this a manual layout problem. ChemIllusion keeps the geometry and the chemical meaning together, so the object can stay clean while you move it, export it, or use it in a lesson.
How the ChemIllusion tool works
The Newman button lives on the Generator toolbar. Click it to open a preset picker with common conformers such as ethane staggered, ethane eclipsed, butane anti, butane gauche, a haloalkane template, and a blank staggered projection.
When you choose a preset, ChemIllusion places a Newman projection as a canvas object. It is separate from the embedded Ketcher molecule editor, so the tool does not need to patch Ketcher internals. The projection lives in ChemIllusion canvas state with sidecar metadata for its front and back substituents.
That means it behaves like the rest of the canvas: move it, resize it uniformly, duplicate it, place it beside molecules and arrows, and export it with the figure.
Changing substituents without redrawing
The newest piece is substituent editing. Start from a preset close to what you need, select a substituent, and change the label. For example, start from butane anti and change a front hydrogen to Br to create a substituted Newman projection without rebuilding the diagram.
The renderer keeps the connecting atom centered on the bond line. For CH3, the carbon is the attachment atom, so the C sits on the vector and H3 trails away from it. For Br, the Br label itself sits on the vector. That small detail makes the diagram read like chemistry instead of decorative clipart.
Where it helps teaching
For instructors, the tool is useful when preparing conformational analysis slides, worksheets, and LMS material. Drop anti and gauche butane side by side, label the positions you care about, and export a clean figure.
For students, it lowers the drawing overhead. The lesson can focus on what the projection means: which carbon is front, which carbon is back, where the methyl groups sit, and how substituent placement changes the comparison.
Try it
Open the Generator with the Newman projection tool pre-loaded. The gold Newman icon appears on the toolbar — click it to choose a butane preset, then edit a substituent label and place the projection next to your mechanism or teaching figure. Every Newman object placed on the canvas carries auto-generated alt text for WCAG-compliant export to slides and handouts.
Related tools on the same canvas: reaction coordinate diagrams with real ΔH values and CineMol 3D space-filling renders.