Coordination Chemistry

Periodic Properties

The Chemical Bond

In bond formation in a coordination complex, the original d electrons of the transition metal go into nonhybridized d orbitals. Where do the electron pairs donated by the ligand go? Appropriately hybridized orbitals of higher energy (four sp², four dsp², six d²sp³, or six sp³d²) are then filled by the electron pairs donated by the ligand.

Don't sweat this stuff too much. Now you have a bit of familiarity with the molecular orbital picture of coordination complexes. This is the kind of conceptual underpinning that makes understanding concrete.