Carbon–carbon bond formation and cleavage resulting from a long-range metal-promoted redox process in the reactions of nickel( II ) complexes of N,N′-o-phenylenebis(salicylideneamine)

Alkali metals (Li or Na) promote the dimerization of N,N′-o-phenylenebis(salicylideneaminato)nickel(II)[Ni(salophen)], causing the reductive coupling of two imino functional groups between two units, which are joined by a rather long C–C bond [1.58(2)Å] in the dimer [Ni(salophen)Na(tetrahydrofuran)3]2; the dimer is able to transfer two electrons to various substrates by a process cleaving the C–C bond and restoring the original [Ni(salophen)] structure.