https://doi.org/10.1351/goldbook.08805
Molecule that has more valence electrons than is needed to link its atoms by single covalent bonds.
Notes:
- Molecules of unsaturated hydrocarbons or aromatic and heteroaromatic compounds are typical electron-rich molecules. Such compounds can be called electron-rich compounds.
- Formally excess electrons present in a molecule containing conjugated multiple bonds are delocalized electrons. Non-bonding valence electrons present in molecules with heteroatoms, such non-bonding electrons of nitrogen, phosphorus and sulfur atoms, are also taken into account.