D-Orbitals
Definition and meaning of D-Orbitals in chemistry.
D-orbitals are the set of five degenerate atomic orbitals belonging to the d subshell (angular momentum quantum number l = 2), first appearing at the third principal energy level (n = 3) and capable of holding up to 10 electrons.
In more detail
Four of the five d-orbitals (dxy, dxz, dyz, and dx²−y²) share an identical four-lobed "cloverleaf" shape, differing only in their spatial orientation relative to the axes, while the fifth (dz²) has two lobes along the z-axis plus a donut-shaped ring in the xy-plane. In isolated atoms all five are degenerate (equal energy), but in transition metal complexes surrounding ligands break this degeneracy, splitting the set into lower- and higher-energy groups. This splitting underlies crystal field theory and explains the characteristic colors, magnetism, and variable oxidation states of transition metals.
Key facts
| Field | General Chemistry |
|---|---|
| Angular momentum quantum number | l = 2 |
| Number of orbitals (ml values) | 5 (ml = -2, -1, 0, +1, +2) |
| Maximum electrons per subshell | 10 |
In the octahedral complex [Ti(H2O)6]3+, the single 3d electron of Ti3+ sits in a lower-energy t2g orbital; absorbing visible light promotes it to a higher-energy eg orbital, and the wavelengths absorbed give the complex its violet color.
Frequently asked questions
Why are d-orbitals so important for transition metals?
Because valence d electrons participate in bonding and their orbitals split in energy under the influence of surrounding ligands, transition metal complexes display characteristic colors, magnetic behavior, and multiple stable oxidation states.
What shapes do d-orbitals have?
Four of the five d-orbitals (dxy, dxz, dyz, dx²−y²) have a four-lobed cloverleaf shape oriented along different axes, while the fifth, dz², has two lobes along the z-axis surrounded by a donut-shaped ring.