Transition metal carboxylate complexes are coordination complexes with carboxylate (RCO) ligands. Reflecting the diversity of carboxylic acids, the inventory of metal carboxylates is large. Many are useful commercially, and many have attracted intense scholarly scrutiny. Carboxylates exhibit a variety of coordination modes, most common are κ- (O-monodentate), κ (O,O-bidentate), and bridging.