Symmetry Lab › D5h › Cyclopentadienide ion
C₅H₅⁻ Cyclopentadienide ion
Planar 5-membered ring · point group D5h · order 20
- Point group
- D5h — A C5 principal axis, 5 perpendicular C2 axes and a horizontal mirror plane; these also give 5 vertical planes.
- Order
- 20
- Operations
- E, 2C₅, 2C₅², 5C₂, σh, 2S₅, 2S₅³, 5σᵥ
- Shape
- Planar 5-membered ring
- Atoms
- 10 (C × 5, H × 5)
Symmetry elements of C₅H₅⁻
- C₅ — perpendicular to the ring
- C₂ (1) — in the plane, through one atom and the opposite bond midpoint
- C₂ (2) — in the plane, through one atom and the opposite bond midpoint
- C₂ (3) — in the plane, through one atom and the opposite bond midpoint
- C₂ (4) — in the plane, through one atom and the opposite bond midpoint
- C₂ (5) — in the plane, through one atom and the opposite bond midpoint
- σh — the plane of the ring
- σᵥ (1) — perpendicular to the plane, through one atom
- σᵥ (2) — perpendicular to the plane, through one atom
- σᵥ (3) — perpendicular to the plane, through one atom
- σᵥ (4) — perpendicular to the plane, through one atom
- σᵥ (5) — perpendicular to the plane, through one atom
- S₅ — rotate 72°, then reflect in σh
Structure
- C–C 1.40 Å (all equal)
- Six π electrons: aromatic
- The ring in ferrocene
