18 Electron Rule Calculator

Formula

The formula to calculate the Total Number of Electrons (E) for the 18 Electron Rule is:

\[ E = d + s + p + b \]

Where:

\( E \) is the total number of electrons.
\( d \) is the number of the metal's d electrons.
\( s \) is the number of the ligands' s electrons.
\( p \) is the number of the ligands' p electrons.
\( b \) is the number of electrons involved in metal-ligand bonding.

What is the 18 Electron Rule?

The 18 Electron Rule is a chemical rule of thumb used primarily for predicting and explaining formulas and structures of transition metal complexes, particularly organometallic compounds. The rule is based on the fact that the shells of transition metals are most stable when they contain 18 electrons. This includes the metal's d electrons, the s and p electrons of the ligands, and any electrons involved in metal-ligand bonding. The rule is useful in the design and understanding of catalysts.

Example Calculation

Consider an example where:

Number of Metal's d Electrons (d): 8
Number of Ligands' s Electrons (s): 2
Number of Ligands' p Electrons (p): 6
Number of Electrons Involved in Metal-Ligand Bonding (b): 2

Using the formula to calculate the Total Number of Electrons:

\[ E = 8 + 2 + 6 + 2 = 18 \]

This means that the total number of electrons for this example is 18, indicating a stable complex according to the 18 Electron Rule.