A. Small sized metal ions
B. Absorption of light in UV region
C. Complete ns sub-shell
D. Incomplete (n-1) d sub-shell
¨ The color of transition metal compounds arises from the absorption of visible light in the range of 400 to 700 nm. This absorption occurs due to the presence of unpaired electrons in the d orbitals of the metal ion, which can undergo electronic transitions between energy levels when they absorb light.
¨ When a transition metal ion is surrounded by ligands in a complex, the energy levels of its d orbitals split into different energy levels due to the electrostatic interactions between the metal ion and the ligands. The energy required for electronic transitions between these levels falls in the visible light region, causing the complex to absorb specific colors of light and appear colored.
¨ The extent and nature of the d orbital splitting depend on various factors, such as the oxidation state of the metal ion, the identity and geometry of the ligands, and the electronic configuration of the metal ion. The presence of unpaired electrons in the (n-1) d sub-shell is a key factor that determines the color of transition metal compounds.
Submitted by :- Jamil Ahmed