A titanium redox-switch enables reversible C-C bond forming and splitting reactions.

Using an Earth-abundant transition metal to mediate formation and splitting of C-C σ-bonds, in response to electrical stimuli, constitutes a promising strategy to construct complex organic skeletons. Here, we showcase how [ BuN][N] reacts with an isocyanide adduct of a tetrahedral and high-spin Ti complex, [(Tp )TiCl] (1), to enact N-atom transfer, C-N bond formation, and C-C coupling, to form a dinuclear complex, [(Tp )Ti{AdN(N)C-C(N)NAd}Ti(Tp )] (3), with two Ti ions bridged by a disubstituted oxalimidamide ligand ( Bu = -butyl, Tp = hydrotris(3--butyl-5-methylpyrazol-1-yl)borate, Ad = 1-adamantyl). Magnetic and computational studies reveal two magnetically isolated d Ti ions, and electrochemical studies unravel a reversible two-electron oxidation at -0.87 V [FeCp]. Despite these observations, chemical oxidation of 3, ultimately, leads to rupture of the oxalimidamide moiety with C-C bond splitting to form [(Tp )Ti{1,3-μ-AdNCN}Ti(Tp )][B(CF)] (4), which displays an antiferromagnetically coupled Ti configuration, mediated by superexchange through its bridging carbodiimide ligands. A comparative reactivity study of isocyanide toward a transient vanadium nitride [(Tp )V[triple bond, length as m-dash]N(THF)] (5) gives further insight into the structure of putative intermediates involved in the coupling sequence.