Whereas the physics of spin engineering dates back to the groundbreaking findings of quantum chemistry and physics within the first decades of the 20th century, the chemical aspects of spin engineering have received attention especially within the last twenty years. Today, researchers focus on specialized topics, such as the design and synthesis of molecular magnets or other model systems in order to understand and harness the fundamental principles behind phenomena such as the relation between magnetism and chemical reactivity as well as microstructure related mechanical properties of metals and the biochemical impact of spin (e. g. photoreceptor proteins) and spin transport.