Ligand Substitution

Click on each step to display in 3D and on each isomer to show its formation from the intermediate.

The top reaction scheme shows how substitution via a square-pyramidal complex, results in retention of stereochemistry. While reaction scheme 2 shows how reaction via a trigonal-bipyramidal complex, results in isomerization.The isomerization is caused, as there are three possible sites for attack by the incoming ligand with the trigonal-bipyramidal complex as the intermediate.