Ligands influence the catalytic activity of metal complexes in several ways:
Electronic Effects: Ligands can donate or withdraw electron density from the metal center, thereby altering its reactivity. For example, phosphine ligands with electron-donating groups can make the metal center more nucleophilic. Steric Effects: The size and shape of ligands can influence the accessibility of the metal center to substrates. Bulky ligands can prevent unwanted side reactions by blocking certain reactive sites. Stabilization of Intermediates: Ligands can stabilize various intermediates in the catalytic cycle, thereby lowering the energy barriers and increasing the reaction rate.
