Magnetic Moment of Complexes
The magnetic behaviour of a complex, determined by the number of unpaired electrons it contains.
Formula / equation
μ = √(n(n+2)) BM
Unit
BM
In depth
The spin-only formula works well for first-row transition metals, where orbital contributions are largely quenched by the ligand field. Measuring the moment therefore reveals the number of unpaired electrons and distinguishes high spin from low spin configurations directly.
Examples in the real world
A measured 1.73 BM indicates one unpaired electron; 5.92 BM indicates five, as in high spin iron(III).