Symmetry Lab › D7h › Tropylium ion
C₇H₇⁺ Tropylium ion
Planar 7-membered ring · point group D7h · order 28
- Point group
- D7h — A C7 principal axis, 7 perpendicular C2 axes and a horizontal mirror plane; these also give 7 vertical planes.
- Order
- 28
- Operations
- E, 2C₇, 2C₇², 2C₇³, 7C₂, σh, 2S₇, 2S₇³, 2S₇⁵, 7σᵥ
- Shape
- Planar 7-membered ring
- Atoms
- 14 (C × 7, H × 7)
Symmetry elements of C₇H₇⁺
- C₇ — 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
- C₂ (6) — in the plane, through one atom and the opposite bond midpoint
- C₂ (7) — 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
- σᵥ (6) — perpendicular to the plane, through one atom
- σᵥ (7) — perpendicular to the plane, through one atom
- S₇ — rotate 51.42857142857143°, then reflect in σh
Structure
- C–C 1.40 Å (all equal)
- Six π electrons in a seven-membered ring
- The first non-benzenoid aromatic cation
