Symmetry Lab › D2h › Diborane
B₂H₆ Diborane
Two BH₂ groups bridged by two H · point group D2h · order 8
- Point group
- D2h — A C2 principal axis, 2 perpendicular C2 axes and a horizontal mirror plane; these also give 2 vertical planes and a centre of inversion.
- Order
- 8
- Operations
- E, C₂(z), C₂(y), C₂(x), i, σ(xy), σ(xz), σ(yz)
- Shape
- Two BH₂ groups bridged by two H
- Atoms
- 8 (B × 2, H × 6)
Symmetry elements of B₂H₆
- C₂ (z) — perpendicular to the molecular plane
- C₂ (y) — in the molecular plane
- C₂ (x) — in the molecular plane
- i — centre of inversion
- σ (xy) — the plane of the molecule
- σ (xz) — perpendicular to the molecule
- σ (yz) — perpendicular to the molecule
Structure
- B–B 1.77 Å; B–H terminal 1.19 Å, bridging 1.33 Å
- Bridging H above and below the B₂H₄ plane
- Two 3-centre-2-electron B–H–B bonds

Other D2h molecules
trans-[PtCl₂(NH₃)₂]trans-Platin (N atoms shown)N₂O₄Dinitrogen tetroxideC₂H₄Ethylene (ethene)C₂O₄²⁻Oxalate ionC₂F₄TetrafluoroethyleneC₂H₂N₄1,2,4,5-TetrazineAl₂Cl₆Aluminium chloride dimerI₂Cl₆Iodine trichloride dimerC₄H₄N₂PyrazineC₆H₄O₂p-BenzoquinoneC₆H₄Br₂ (para)p-DibromobenzeneC₆H₄Cl₂ (para)p-Dichlorobenzene