Iron is a cheap and environmentally friendly alternative for noble metals in catalysis and the development of new functional materials. Dr Marcus Korb tailored the stability of iron half-sandwich complexes as they can help replacing palladium in C,C cross-coupling reactions for the synthesis of pharmaceuticals and fine chemicals. By applying its reversible redox behaviour, Marcus also developed redox-active macrocycles since they are promising candidates for redox-responsive molecular magnets and fluorophores.