Design and synthesis of base-metal nickel(II) based catalysts: studies on nearly selective formation of 1-butene from ethylene

Abstract

A new family of base-metal nickel complexes [Ni(L1-10)2] (1-10) were synthesized from tridentate meridional ligands L1H to L10H (where H stands for dissociable proton). Different spectroscopic studies were utilized for the characterization of these complexes [Ni(L1-10)2] (1-10). Molecular structures of complexes [Ni(L1)2] (1), [Ni(L3)2] (3) and [Ni(L8)2] (8) were determined by X-ray crystallography. Electronic properties of complexes [Ni(L1)2] (1) [Ni(L3)2] (3) and [Ni(L8)2] (8) were elucidated with the help of DFT and TD-DFT calculations. Complexes [Ni(L1-10)2] (1-10) were utilized as catalysts for the synthesis of 1-butene from ethylene using diethyl aluminium chloride as a co-catalyst. A nearly selective formation of 1-butene was observed and productivity up to 17.50 [kg (product/gm catalyst)] h−1 bar−1 was found after examining the catalytic activity of complexes 1-10. A reaction pathway was also proposed for the conversion of ethylene to 1-butene.