the empirical formula AlCl₃ actually has the molecular formula of Al₂Cl₆ under ordinary conditions. Due to their ?-basicity, the halide ligands are weak field ligands. Due to a smaller crystal field splitting energy, the halide complexes of the first transition series are all high spin when possible. These complexes are low spin for the second and third row transition series. Only [CrCl₆]^3- is exchange inert.

Homoleptic metal halide complexes