Two-coordinate d9 complexes.: Synthesis and oxidation of NHC nickel(I) amides

Reaction of the d(9)-d(9) Ni(I) monochloride dimer, [(IPr) Ni(mu-CI)](2) (1), with NaN(SiMe3)(2) and LiNHAr (Ar = 2,6-diisopropylphenyl) gives the novel monomeric, 2-coordinate Ni(I) complexes (IPr)Ni{N(SeMe3)(2)} (2) and (IPr)Ni(NHAr) (3). Reaction of 2 with Cp2Fe+ results in its 1-e(-) oxidation followed by beta-Me elimination to give a base-stabilized iminosilane complex [(IPr)Ni(CH3){k(1)-N(SiMe3)=SiMe2.Et2O}][BAr4F] (6). Oxidation of 3 gives [(IPr)Ni(eta(3)-NHAr)(THF)][BAr4F] (4), which upon loss of THF affords dimeric [(IPr)Ni(N,eta(3):NH=(C6Pr2H3)-Pr-i)](2)[BAr4F](2) (5).