Symmetry & Group Theory In Chemistry Direct

) that show if a property stays the same or flips sign during an operation. 4. Chemical Applications

A vibration must change the molecule's dipole moment (matches in the character table). Symmetry & Group Theory in Chemistry

A is an action (like a rotation) that leaves the molecule looking exactly as it did before. Each operation is associated with a symmetry element (the point, line, or plane where the action happens). Identity ( ): Doing nothing. Every molecule has this. Rotation ( Cncap C sub n ): Rotating by around an axis. (e.g., C2cap C sub 2 180∘180 raised to the composed with power Reflection ( ): Reflecting through a plane. σvsigma sub v (vertical): Contains the main rotation axis. σhsigma sub h (horizontal): Perpendicular to the main axis. Inversion ( ) that show if a property stays the

): A rotation followed by a reflection through a perpendicular plane. 2. Point Groups A is an action (like a rotation) that

Only orbitals of the same symmetry can overlap to form bonds. This is the basis of SALCs (Symmetry Adapted Linear Combinations). Vibrational Spectroscopy:

Symmetry determines "selection rules" (whether a transition is allowed or forbidden).