Nitrogen- and phosphorus-coordinated nickel(II) complexes as catalysts for the oligomerization of ethylene

Nickel(II)-based Schiff base N,N-complexes 1a, bis(imino)oxalate complexes 1b, and N,P-coordinated complexes 2 are active precatalysts together with the cocatalyst MAO for the oligomerization of ethylene and the production of olefins with short chain lengths.