The book "Electronic and Catalytic Properties of Metal Complexes" offers a comprehensive examination of the electronic and catalytic properties of iron porphyrin complexes. It is based on the research of Dr. Samuel de Visser and employs advanced computational methods such as density functional theory, as well as quantum mechanical and molecular mechanics. The research aims to provide insights into the mechanisms and functions of enzymes. Notably, it highlights the correlation between the epoxidation rate and the ionization energy of olefins, as well as the effects of subtle environmental factors on the spin state ordering in diiron(III)bisporphyrin complexes. This specialized book is intended for readers interested in the intersection of chemistry and physics who wish to gain in-depth knowledge about organometallic complexes.