The synthesis and characterization of the two homoleptic mononuclear nickel complexes (2,6-Dipp(2)C(6)H(3)NH)(2)Ni (1) and [2-C(H)NDippC(6)H(4)NH](2)Ni (2) (Dipp = 2,6-(Pr2C6H3)-C-i) are described. 1 is formally two-coordinate and adopts a strictly linear geometry, while 2 features a slightly distorted square-planar geometry. Electrochemistry of 1 and 2 shows that they can be reduced to the corresponding nickel(I) species and oxidized to the corresponding nickel(III) species reversibly or quasi-reversibly. A solid-state magnetic measurement (mu(eff) = 2.79 mu(B)) for paramagnetic 1 indicates the presence of two unpaired electrons on the nickel center.