18 Electron Rule In Cordination Compounds |

Added: 2026-06-02

The 18 Electron Rule states that transition metal complexes achieve maximum stability when the central metal atom has 18 valence electrons, corresponding to a filled valence shell configuration. This rule is particularly applicable to organometallic compounds and metal carbonyls. To calculate the total valence electrons in a complex, one must sum the valence electrons from the metal atom, the ligands, and account for any charges on the complex. Important exceptions exist for certain electron-deficient complexes and early transition metals. This rule serves as a fundamental guideline for predicting the stability and reactivity of coordination compounds in inorganic chemistry.