Alkali Metal‐Transition Metal π‐Complexes

Abstract

Abstract In this progress report a new principle is described for the synthesis of multimetal π‐complexes with hitherto unknown structural features. The nickel(0)‐olefin complexes 1,5,9‐cyclododecatrienenickel(0) and bis(1,5‐cyclooctadiene)nickel(0) react unexpectedly with main‐group metals, in particular alkali metals, their hydrides, and organometallic compounds, to give nickelligand species with a surplus charge. These species endeavor to transfer the excess charge onto π‐ligands such as olefins or dinitrogen. Multimetal complexes with electron rich transition metal π‐ligand units can, in addition, be prepared from metallocenes, alkali metals, and unsaturated compounds. The syntheses, structures, and reactions of this new class of substances will be summarized.