Structure of a nickel(II) complex of the deprotonated anion of 3,10-dimethyl-4,9-diaza-3,9-dodecadiene-2,11-dione dioxime

μ-[3,10-Dimethyl-4,9-diaza-3,9-dodecadiene- 2,11 -dione dioximato(1 - )-μ- O,N,N',N'',N''']- nickel(II) perchlorate, [Ni(C₁₂H ₂₁N₄O₂)]⁺.ClO₄ ^-, M_r = 411·5, triclinic, P1̄, a = 6·533 (2), b = 10·840 (3), c = 12·979Å, α=103·57(3), β=95·76(3), γ= 103·16 (2)°, V= 858·5 (5) ų, Z= 2, D_x = 1·592 Mg m^-3, λ(Mo Kα) = 0·71073 Å, μ = 1·33 mm^-1, F(000) = 428, R = 0·0440, wR = 0·0494 for 2417 independent reflections at 296 K. An oxime proton is lost from the ligand in forming the complex and the remaining oxime proton forms an intramolecular hydrogen bond between the two oxime oxygens. The Ni^II n atom is in a distorted square planar coordination. The average values for the important bond distances are Ni-N(oxime) = 1·871, Ni-N(imine) = 1·907, O⋯O = 2·443 Å for the intramolecular hydrogen bond.