Symmetry Lab › D2d › Spiropentane
C₅H₈ Spiropentane
Two perpendicular three-membered rings sharing one carbon · point group D2d · order 8
- Point group
- D2d — A C2 principal axis, 2 perpendicular C2 axes and 2 dihedral mirror planes that bisect them; the principal axis is also an S4 axis.
- Order
- 8
- Operations
- E, 2S₄, C₂, 2C₂′, 2σd
- Shape
- Two perpendicular three-membered rings sharing one carbon
- Atoms
- 13 (C × 5, H × 8)
Symmetry elements of C₅H₈
- C₂ — through the spiro carbon, along both ring bisectors
- S₄ — rotate 90°, then reflect: swaps the two rings
- C₂′ (1) — through the spiro carbon, between the ring planes
- C₂′ (2) — through the spiro carbon, between the ring planes
- σd (1) — the plane of one ring
- σd (2) — the plane of the other ring
Structure
- C–C 1.48–1.52 Å
- The two rings lie in perpendicular planes
- Same point group as allene
