The phenol-based macrocyclic ligands (L2,3)2- and (L2,4)2-, derived from the [2:1:1] condensation of 2,6-diformyl-4-methylphenol, ethylenediamine, and 1,3-trimethylenediamine or 1,4-tetramethylenediamine, have a salen-like metal-binding site (salen = N,N‘-ethylenedisalicylideneaminate) and a saltn- or salbn-like metal-binding site (saltn = N,N‘-trimethylenedisalicylideneaminate, salbn = N,N‘-tetramethylenedisalicylideneaminate) sharing the phenolic moieties. They form the (μ-phenoxo)2CoIIMII complexes [CoMn(L2,3)(AcO)]ClO4·DMF (1), [CoMn(L2,4)(AcO)]ClO4 (2), [CoCo(L2,3)(AcO)]ClO4 (3), [CoCo(L2,4)(AcO)]ClO4 (4), [CoZn(L2,3)(AcO)]ClO4 (5), and [CoZn(L2,4)(AcO)]ClO4 (6). Complex 1 crystallizes in the monoclinic space group P21/c, with a = 10.027(3) Å, b = 11.713(3) Å, c = 26.821(9) Å, β = 93.85(2)°, V = 3142(1) Å3, and Z = 4. The Co and Mn ions are bridged by the two phenolic oxygens of the macrocycle and an acetate group in the syn-syn mode. The CoII in the salen site is of low-spin and assumes a square-pyramidal geometry with an acetate oxygen at the axial site. The MnII has a cis six-coordinate geometry with respect to the acetate oxygen and the DMF oxygen. The Mn is displaced 0.955 Å from the basal N2O2 least-squares plane. [CoMn(L2,4)(AcO)]ClO4·DMF (2 ‘) crystallizes in the monoclinic space group P21/c, with a = 10.166(5) Å, b = 11.934(4) Å, c = 27.380(8) Å, β = 93.97(3)°, V = 3313(1) Å3, and Z = 4. It has a dinuclear core similar to that of 1, with square-pyramidal CoII in the salen site and cis six-coordinate MnII in the salbn site. Complex 3 crystallizes in the triclinic space group P1̄, a = 12.118(3) Å, b = 12.156(2) Å, c = 9.977(1) Å, α = 112.49(1)°, β = 99.22(2)°, γ = 77.63(2)°, V = 1321.1(5) Å3, and Z = 2. Both CoII ions in the salen and saltn sites assume a square-pyramidal geometry with a bridging acetate group in the syn-syn mode. The displacement of the Co in the saltn site, from the basal N2O2 least-squares plane toward the apical acetate oxygen, is 0.53 Å. Complex 5 is found to be isostructural with 3. The complexes 1, 2, 4, 5, and 6 are reversibly oxygenated in DMF at 0 °C to afford a μ-peroxo dimer complex [{CoIIIMII(L)(AcO)}2(O2 2-)]2+. Complex 3 also forms such a μ-peroxo dimer complex but is irreversibly oxidized through an intramolecular-type μ-peroxo complex [CoIIICoIII(L2,3)(AcO)(O2 2-)]+.

A di(μ-phenoxo)CoIICuI complex, [CoCu(L)]ClO4·0.5DMF, has been prepared where (L)2- is a macrocyclic dinucleating compartmental ligand derived from the 2:1:1 condensation of 2,6-diformyl-4-methylphenol, ethylenediamine, and 3-thia-1,5-pentanediamine, having a salen-like N2O2 metal-binding site (salen = N,N‘-ethylenedisalicylideneaminate) and an N2O2S site sharing the phenolic oxygens. It crystallizes in the monoclinic space group P21/n, a = 7.087(1) Å, b = 19.593(6) Å, c = 19.447(3) Å, β = 96.29(1)°, V = 2684(1) Å3, and Z = 4. The CoII resides in the salen-like site and assumes a planar geometry. The CuI in the N2O2S site has a planar four-coordinate geometry with two phenolic oxygens and two imine nitrogens; the thioether sulfur on the lateral chain is situated at an axial site of the CuI, but the Cu--S separation is very large (3.08 Å). In the {CuN2O2} chromophore, the two Cu−O bond distances (2.333(5) and 2.385(5) Å) are significantly long relative to the two Cu−N bond distances (1.984(6) and 1.929(4) Å). Further, the N−Cu−N angle is very large (128.2(2)°), whereas the O−Cu−O angle is very small (65.2(2)°). Analogous CuIICuI and CoIIPbII complexes of (L)2-, [CuIICuI(L)]ClO4 and [CoPb(L)](ClO4)2, have been prepared. The DMF adduct of [CuIICuI(L)]ClO4, [CuIICuI(L)]ClO4·0.5DMF, crystallizes in the monoclinic space group P21/n, a = 6.957(2) Å, b = 23.774(2) Å, c = 7.758(3) Å, β = 94.72(3)°, V = 1278.8(6) Å3, and Z = 4. The dinuclear core resembles that of the CoIICuI complex and shows distortions about the CuI similar to those found for the CoIICuI complex. The di-DMF adduct of the CoIIPbII complex, [CoPb(L)(DMF)2](ClO4)2, crystallizes in the monoclinic space group P21/n, a = 16.265(2) Å, b = 12.640(2) Å, c = 18.584(3) Å, β = 90.43(1)°, V = 3820.5(8) Å3, and Z = 4. The CoII in the N2O2 site has a square-pyramidal geometry together with a DMF oxygen at the apical site. The PbII in the N2O2S site has a six-coordinate geometry with the further coordination of a DMF molecule. The reactivity of the CoIICuI complex toward dioxygen has been studied in comparison with the CuIICuI and CoIIPbII complexes. The CoIICuI complex in DMF is very sensitive to dioxygen and is oxidized at −50 °C. The CuIICuI complex is inert to dioxygen. The CoIIPbII complex is oxygenated at 0 °C to form a peroxo dimer (PbIICoIII−O−O−CoIIIPbII). The high sensitivity of the CoIICuI complex to dioxygen is explained by the irreversible oxidation to a CoIIICuII species through an intramolecular-type peroxo complex (CoIII−O−O−CuII).