What can occur frequently in five-coordinate complexes due to steric effects?

In five-coordinate complexes, deviations from ideal geometry frequently occur due to steric effects. This is primarily because, with five ligands, the spatial arrangement becomes more complicated than in lower coordination numbers. The ideal geometry for a five-coordinate complex is trigonal bipyramidal or square pyramidal, but the steric demands of the ligands can lead to distortions from these ideal shapes.

When large ligands are present, their size can hinder optimal arrangements that would minimize steric repulsion. As a result, the ideal bond angles and bond lengths may be adjusted to accommodate the sterics of the ligands, leading to a geometry that is not perfectly trigonal bipyramidal or square pyramidal.

High symmetry would imply a uniform distribution of the ligands around the central atom, which is not typically maintained in five-coordinate complexes due to the varying sizes and shapes of the ligands, resulting in a less symmetrical arrangement. Perfect tetrahedral formation would not be applicable here, as five-coordinate complexes cannot adopt tetrahedral geometry. Increased ligand charge is also not directly related to steric effects; rather, it involves electronic considerations like donor-acceptor interactions, which are separate from sterics.