Indenylnickel(II) N-Heterocyclic Carbene Complexes: Synthesis via Indene Elimination and Catalytic Activity for Ethylene Dimerization

The reaction of 1,3-diisopropylimidazolium
salt with (Ind)2Ni results in the synthesis of 1,3-diisopropylimidazol-2-ylidene complexes of (Ind)Ni(L)X [Ind
= indenyl; L = 1,3-diisopropylimidazole-2-ylidene; X =
Cl (1), Br (2)], which were characterized by elemental
analysis, NMR, and X-ray crystal determination. The
complexes in combination with MMAO can catalyze the
dimerization of ethylene with a high selectivity.