What is the Difference Between 18 Electron Rule and EAN Rule?

Both the 18-electron rule and the Effective Atomic Number (EAN) rule indicate that a stable compound should have a noble gas electron configuration. However, there are some differences between the two rules:

1. Focus: The 18-electron rule specifically considers the valence electrons of the metal atom, while the EAN rule focuses on the total electron content of the metal atom.
2. Application: The 18-electron rule is mainly applied to organometallic complexes, while the EAN rule can be applied more broadly to transition metals.
3. Electron counting: The 18-electron rule simplifies the EAN rule by considering only the valence electrons of the transition metals, which can hold a total of 18 electrons.

In summary, both rules aim to describe the stability of compounds based on a noble gas electron configuration. The 18-electron rule is a simplification of the EAN rule, focusing on the valence electrons of the metal atom and is mainly applied to organometallic complexes. The EAN rule, on the other hand, considers the total electron content of the metal atom and can be applied more broadly to transition metals.

Comparative Table: 18 Electron Rule vs EAN Rule

The 18-electron rule and the EAN (Effective Atomic Number) rule are both concepts related to the stability of transition metal complexes. Here is a table comparing the differences between the two rules:

Both rules indicate that obtaining a noble gas electron configuration makes a metal atom stable. The 18-electron rule focuses on the valence electrons of the metal atom, while the EAN rule considers the whole electron content of the metal atom. The 18-electron rule is mainly discussed under organometallic compounds, whereas the EAN rule is applicable to a broader range of transition metal complexes.