Transition metal salen complexes in bioinorganic and medicinal chemistry

Salen is a common abbreviation for tetradentate N₂O₂ bis-Schiff base bis-phenolate ligands. Due to the ease of their synthesis, rich coordination chemistry and photophysical properties, biological and catalytic activity, salen complexes are widely employed in materials science, catalysis and biomedical science with applications ranging from enzyme models to therapeutics and biosensors to bioinspired nanotechnology. This review gives an overview of the role of metallosalens in bioinorganic and medicinal chemistry and discusses their applications as enzyme mimics, artificial enzyme cofactors, therapeutics, sensors, DNA cleavage and footprinting agents, quadruplex DNA binders and artificial DNA base pairs.