ChemInform Abstract: Organometallic Lanthanide Chemistry

Abstract

Publisher Summary This chapter discusses organolanthanide chemistry. Organolanthanide chemistry currently is one of the most rapidly developing areas of organometallic chemistry. The lanthanide elements are differentiated from other metallic elements by the fact that their valence electrons are in 4f orbitals. The highly ionic, trivalent organolanthanide complexes appeared to have little potential to interact with small-molecule substrates that provide such a rich chemistry for the transition metals. The synthesis, structure, and physical and chemical properties of organolanthanide complexes containing only polyhaptocyclopentadienyl and cyclooctatetraenyl metal–carbon bonds are covered in other reviews. For many years, the only fully characterized homoleptic organolanthanide complex and the only structurally characterized Ln–C species of any type was the tetrakis complex. One of the most recent and rapidly developing areas of organolanthanide chemistry involves species containing Ln–H bonds. The first evidence for the existence of organolanthanide hydride molecules arose from a study of catalytic hydrogenation by lanthanide metal vapor reaction products. There are two low-valent oxidation states available to the lanthanides under normal conditions: the +2 oxidation state and the formally zero oxidation state found in the elemental metals. The pentamethylcyclopentadienyl ligand, C5Me5, has proven to be of great importance in organometallic chemistry. The thesis that the lanthanide elements offer something unique to organometallic chemistry has been proven in a variety of ways.