D-d transition

A D-d transition is a type of electronic change that occurs in certain metal ions, especially transition metals, where electrons move between specific closely spaced energy levels known as d-orbitals. These transitions are often responsible for the vivid colors seen in many metal-containing compounds. Since D-d transitions involve electrons shifting within the same type of orbital, they are typically less intense and are influenced by the metal's environment, such as the ligands (molecules attached to the metal). This phenomenon helps scientists understand the structure and bonding of metal complexes.