Ideal molecules, honestly drawn.

Interactive 3D models for conformational analysis and stereochemistry, drawn in ideal geometry. Single bonds: C–C 1.54 Å, C–H 1.09 Å, 109.47° everywhere. Double bonds: C=C 1.34 Å, 120°. Triple bonds: C≡C 1.20 Å, 180°. True ideal bond lengths and angles, no minimization.

Geometry verified the badge at the top of every page

How to use a module

Rotate and zoomDrag to rotate; scroll or pinch to zoom . Works with a mouse, trackpad, or fingers on a tablet.

MeasureClick 2 atoms for a distance, 3 for an angle, 4 for a dihedral. Every number is read from the ideal coordinates.

Read the badge● Green: everything ideal. ● Amber: something is deliberately non-ideal, and the badge lists exactly what.

Draw your own

✎Draw it yourself: ideal 3D and Newman projectionSketch any alkane, cycloalkane, alkene or alkyne with ChemDraw-style tools. The 3D model is constructed on the diamond lattice in ideal geometry, never optimized; look down any bond, turn it through 360° with the energy diagram, flip chairs, count gauche interactions.

Conformational analysis

1Pentane: 2D and 3DSkeletal and Lewis drawings beside a rotatable model. Measure distances, angles, dihedrals. 2Butane rotation profileTurn the C2–C3 bond through 360° with a live Newman projection and a clickable energy diagram. 3Pentane conformersAnti and gauche conformers, the syn-pentane clash, and a gauche-counting exercise. 4Cyclohexane ring flipChair, twist-boat, boat, flipped chair, all with tetrahedral angles; animated flip; energy diagram. 5Dimethylcyclohexane chairsAll seven isomers, both chairs, 1,3-diaxial and gauche strain, ring-flip populations. 6Alkylcyclohexane chairsMethyl to tert-butyl: every chair and rotamer, and why the A-value jumps. 7Fused ringstrans- and cis-decalin, adamantane, and the steroid A/B/C core on the diamond lattice. 8Ring strainCyclopropane to cyclohexane: the angle the lattice cannot give, eclipsing, strain energies.

Stereochemistry

9One stereocenter: R or S?Rank the groups, trace 1→2→3 with group 4 away, wedge-and-dash drawing, mirror image, superimpose test. 10Two stereocenters: Fischer, zigzag, Newman, sawhorseOne configuration, four drawings, meso forms, and a dihedral slider that never changes R/S. 11Homotopic, enantiotopic, diastereotopic hydrogensThe replacement test in 3D on propane, ethanol, 2-butanol, and 3-pentanol. 12Alkenes: cis/trans and E/ZPlanar sp² geometry, priorities, and the cis clash.