Symmetry-allowed, symmetry-disallowed

Definition

In the context of organic chemistry, a symmetry-allowed reaction occurs when the molecular orbitals of reacting molecules align in such a way that allows for electron sharing or transfer, facilitating the reaction. These reactions comply with the symmetry rules governing conjugated pi systems, enabling smooth transition states.

Related terms

Molecular Orbitals: Atomic orbitals combine to form molecular orbitals, which describe the spatial distribution of electrons in a molecule.

Conjugated Pi Systems: Systems where p-orbitals overlap across adjacent atoms allowing for delocalization of pi electrons over multiple bonds.

Transition State: The high-energy state through which reactants must pass to become products in a chemical reaction.