Tridentate NacNac Tames T‐Shaped Nickel(I) Radical.

The reaction of a nickel(II) chloride complex containing a tridentate β‐diketiminato ligand with a picolyl group [2,6‐iPr2‐C6H3NC(Me)CHC(Me)NH(CH2py)]Ni(II)Cl (1)] with KSi(SiMe3)3 conveniently afforded a nickel(I) radical with a T‐shaped geometry (2). The compound's metalloradical nature was confirmed through electron paramagnetic resonance (EPR) studies and its reaction with TEMPO, resulting in the formation of a highly unusual three‐membered nickeloxaziridine complex (3). When reacted with disulfide and diselenide, the S−S and Se−Se bonds were cleaved, and a coupled product was formed through carbon atom of the pyridine‐imine group. The nickel(I) radical activates dihydrogen at room temperature and atmospheric pressure to give the monomeric nickel hydride. [ABSTRACT FROM AUTHOR]