Übergangsmetallorganische Reaktionskaskaden zum Aufbau höher aggregierter Systeme: Nickelacyclische Carboxylate als Precursoren für die Synthese eines Oxinato‐Nickel(II)‐Tetramers

Organo Transition Metal Cascade Reactions for Forming Higher Aggregeted Systems: Nickelacyclic Carboxylates as Precursors for the Synthesis of a Oxinato‐Nickel(II)‐Tetramer Diisopropyl‐8‐oxychinolylphosphinite ( 2 ) reacts with the nickelacycle [(py) 2 Ni‐CH 2 CH 2 ‐COO] under formation of the thermically stable nickelalactones [( 2 )Ni‐CH 2 CH 2 ‐COO] ( 4 ) the solid state structure of which was determined by an X‐ray crystallographic analysis. In 4 the ligand acts as a six‐membered chelating ligand with P,N coordination. According to the NMR spectrathis structure is present in solution as well. However, the stronger electron‐withdrawing diphenyl‐8‐0xychinolylphosphinite reacts under similar conditions in further reactions yielding the tetranuclear oxinato‐diphenylphosphinato‐Ni(II) complex 6 in the presence of oxygen. The structure of 6 was determined by an X‐ray analysis. The formation of 6 is the result of a reaction cascade of at least five metal‐assisted reactions which occur step by step, and to some extend in parallel reactions.