This lecture covers the preparation and stabilities of complexes, including redox reactions, direct reactions, substitution, photochemical reactions, and catalytic reactions. It discusses the kinetics, thermodynamics, ligand exchange, leaving groups, and complex formation, emphasizing the importance of formation constants and stability constants. The lecture also explores the influence of charge and size of metals on stability, the Irving Williams Series, and the Hard Soft Acid Base Theory. It delves into the strength of ligands, Bronsted acid-base theory, and the chelate effect in stabilizing different chelate rings.