[N-(2-Benzoylphenyl)benzamido-κ 2 N,O](η 1 -benzyl)(trimethylphosphine)Ni(II ) (3) is prepared by the reaction of potassium N-(2-benzoylphenyl)benzamide and Ni(η 3 -CH 2 C 6 H 5 )Cl(PMe 3 ). When 3 is treated with one equivalent of B(C 6 F 5 ) 3 , one obtains a zwitterionic complex, [PhC(O) C 6 H 4 N C(Ph)OB(C 6 F 5 ) 3 -κ 2 N,O]Ni(η 1 -CH 2 C 6 H 5 )(PMe 3 ) (4). When two equivalents of B(C 6 F 5 ) 3 is added, PMe 3 is abstracted to give a η 3 -benzyl zwitterionic complex, [PhC(O) C 6 H 4 N C(Ph)OB(C 6 F 5 ) 3 -κ 2 N,O]Ni(η 3 -CH 2 C 6 H 5 ) (5). Solid structures of 4 and 5 were determined by X-ray crystallography. When ethylene is added to 5, low molecular weight polyethylene is obtained.