Intricate Road to Linear Anionic Nickel(I) Hexamethyldisilazanide [Ni(N(SiMe 3 ) 2 ) 2 ] .

In this report, we present intricate pathways for the synthesis of linear nickel(I) silylamide K{m}[Ni(NR 2 ) 2 ] (NR 2 = -N(SiMe 3 ) 2 ). This is achieved first via the reduction of nickel(II) trisamide Li(donor) 4 [Ni(NR 2 ) 3 ] (Li(thf) x [ 1 ]) with KC 8 in the presence of 18-crown-6 or crypt.222. In due course, the behavior of Li(donor) 4 [Ni(NR 2 ) 3 ] as a source of masked two-coordinate nickel(II) hexamethyldisilazanide is explored, leading to the formation of nickel(I) and nickel(II) N-donor adducts, as well as metal-metal-bonded dinickel(I) trisamide K(toluene)[Ni 2 (NR 2 ) 3 ] (K(toluene)[ 5 ]). Finally, a convenient and reliable synthesis of K{m}[Ni(NR 2 ) 2 ] by ligand exchange of phosphines in [Ni(NR 2 )(PPh 3 ) 2 ] with K{m}(NR 2 ) is presented. This allows for the comprehensive analysis of its electronic properties which reveals a fluxional behavior in solution with tight anion/cation interactions.