A compact drawing hides a crowded three-dimensional framework
Ibogaine’s 2D structure maps connectivity. Its 3D structure determines the spatial arrangement of that connectivity.
In a two-dimensional chemical drawing, the indole ring is the familiar aromatic region: a benzene ring fused to a five-membered nitrogen-containing ring. The remaining framework folds into the characteristic iboga skeleton, a rigid, bridged polycyclic system containing a tertiary amine.
Three-dimensional models make the constraint more apparent. Several saturated rings, bridge positions, and stereocenters hold substituents in specific orientations. That architecture is why an image of the molecule is more than a collection of atom labels: spatial arrangement changes how a compound can fit, ionize, and be transformed.