PHYSICS · Multi-part · Fermi University Physics · Mathematical Methods for Physics · Group theory and symmetry · Group theory and symmetry
Invariance, Ch Point groups and crystallographic symmetry
Problem
Hydrogen peroxide, H−O−O−H, is not planar. Seen along the O-O bond, the two O-H bonds are turned from each other by a dihedral angle that is neither 0∘ nor 180∘. Treat the molecule as rigid.
((a)) Find its symmetry elements and its point group, and check the order by counting an orbit and a stabiliser.
((b)) Using the polarity and chirality rules, say whether it can have a permanent dipole, and along which direction, and whether it can exist in two mirror-image forms.
((c)) Repeat (a) and (b) for a planar form with the two hydrogens on opposite sides of the O-O bond (dihedral angle 180∘).