Synthesis, structure, and properties of di-μ-phenoxo-bridged dinuclear Cu(II)Ni(II) and Cu(II)Co(II) complexes and cyclic di-μ-phenoxo-μ-amido- bridged tetranuclear Cu₂(II)Zn₂(II) and Cu₄(II) complexes derived from the 1,2-bis(2-oxidobenzamidato)benzenecuprate(II) dianionic ligand-complex

Dipotassium N,N'-1,2-phenylenebis(2-carbamoyl-χN-phenolato- χO]cuprate(II)), K₂[CuL], reacts with nickel(II), cobalt(II), and zinc(II) acetates, and 2,2'-bipyridine in a 1: 1: 2 molar ratio in methanol to yield the hetero-metal dinuclear complexes [CuLNi(bpy)₂] · 3MeOH (1.3MeOH), [CuLCo(bpy)₂] · 2DMF (2.2DMF), and [CuLZn(bpy)₂].1.5H₂O (3), respectively. Crystal data for 1 :P1̄ (No. 2) with α = 15.969(2), b = 23.494(3), c = 12.705(2) Å, α = 92.15(1), β = 91.652(10), γ = 101.521(9)°, V = 4663(1) ų, and Z = 4; 2, P2₁/c (No. 14) with a = 12.604(3), b = 24.364(5), c = 13.823(2) Å, β = 94,49(1)°, V = 4231(1) ų, and Z = 4. 1 and 2 have a similar discrete di-μ-phenoxo-bridged dinuclear structure, in which the Cu(II) ion assumes a square-planar geometry with the N₂O₂ donors atoms consisting of two amido nitrogen and two phenoxo oxygen atoms of the tetradentate ligand, and the Ni(II) or Co(II) ion assumes an octahedral geometry with the two phenoxo oxygens of the tetradentate ligand and four nitrogen atoms from two bpy. The magnetic-susceptibility data were reproduced based on the isotropic spin Hamiltonian H = - 2JS₁ · S₂ with J = -118.0 cm^-1,(S₁, S₂) = (1/2, 1) for 1 and J = 11.0 cm^-1,(S₁, S₂) =(1/2, 3/2) for 2, respectively. When 3 was recrystallized from DMF/2- propanol, [CuLZn(bpy)]₂ · 2DMF (3') was obtained. The 1: 1: 1 reaction of K₂[CuL'], copper(II) acetate monohydrate, and 2,2'-bipyridine in methanol yielded [CuL'Cu(bpy)]₂ · 2MeOH (4), (H₄L' = 1,2- bis(hydroxybenzamido)ethane). Crystal data for 3': Pbca (No. 61) with α = 19.143(2), b = 18.195(2), c = 16.832(3) Å, and Z = 4; 4, P2₁/n (No. 14) with a = 13.407(1), b = 13.172(4), c = 13.764(2) Å, β = 94.11(1)°, V = 2424.4(8) ų, and Z = 4. 3' and 4 have a similar cyclic di-μ-phenoxo-μ- amido-bridged tetranuclear structure, which can be described as two di-μ- phenoxo-bridged dinuclear units bridged together by the coordination of one amido oxygen atom from each dinuclear unit to the zinc(II) or copper(II) ion of the other dinuclear unit, with Zn(1)-O(3)* = 2.004(3) and Cu(2)-O(4)* = 1.924(4) Å, bond distances, respectively. In the tetranuclear structure, the copper(II) ion coordinated by the tetradentate ligand assumes a square- planar geometry and the zinc(II) or the other copper(II ion assumes a square- pyramidal coordination geometry with two phenoxo-oxygen atoms, two nitrogen atoms of bpy, and one amido oxygen atom. The magnetic susceptibility of 4 was reproduced by an equation derived from the H = - 2J(S₁ · S2 +S₃.S₄) - 2J'(S₂ · S₃+S₄ · S₁) spin Hamiltonian with J = -14.6cm^-1 and J' = - 4.0cm^-1.