Redetermination of bis­(2-formyl­phenolato-κ(2) O,O′)nickel(II) as bis­[2-(imino­meth­yl)phenolato-κ(2) N,O′]nickel(II)

The crystal structure of bis­(2-formyl­phenolato-κ(2) O,O′)nickel(II), [Ni(C(7)H(5)O(2))(2)], a square-planar centrosymmetric complex, has been reported previously [Li & Chen (2006). Acta Cryst. E62, m1038–m1039]. However, a number of warning signs allows the assumption that the carbonyl group in the salicylaldehydate ligand of the claimed complex is incorrect. The crystal structure was therefore redetermined on basis of the originally deposited structure factors. After substituting the carbonyl O atom by an N atom, the model can be completed with an imine H atom, which was clearly discernible in a difference map. The resulting model, corresponding to bis­[2-(imino­meth­yl)phenolato-κ(2) N,O′]nickel(II), [Ni(C(7)H(6)NO)(2)], converges well and none of the previous structural alerts remains. This reinter­pretation is also consistent with the published synthesis, which was carried out using salicylaldehyde in the presence of aqueous NH(3). The reinter­preted structure is virtually identical to earlier reports dealing with this bis-iminato Ni(II) complex.