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Dinuclear Mn2(II,II) complexes [Mn2(Lm,n)(RCOO)2] ((m,n) = (2,3), (2,4), (3,3); R = CH3, C6H5) have been prepared where (Lm,n)2− denotes dinucleating macrocycles with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined through two lateral chains, –(CH2)m– and –(CH2)n–, at the imino nitrogens. The complex [Mn2(L3,3)(CH3COO)2] crystallizes in the monoclinic space group P21/n with a = 18.795(5), b = 7.608(2), c = 10.081(1) Å, β = 92.89(2)°, V = 1439.7 Å3, and Z = 2. The refinement converges with R = 6.38 and Rw = 9.63% based on 2727 reflections with |Fo| ≥ 3σ(|Fo|). A pair of Mn(II) ions are bridged by the two phenolic oxygens with a Mn–Mn separation of 3.367(1) Å. An acetate group coordinates bidentately to each Mn(II) to afford a six-coordinate geometry about the metal ion. The oxidation of [Mn2(L3,3)(CH3COO)2] with Br2 forms a mixed-valence Mn2(II,III) complex [Mn2(L3,3)(CH3COO)Br2]·H2O. The Mn2(II,II) and Mn2(II,III) complexes show catalytic activity for decomposing H2O2 in DMF or DMSO. The involvement of the Mn2(II,III)/Mn2(II,IV) cycle in the catalytic process is inferred based on visible and ESR spectroscopic studies of the reaction mixture.

The complex [CuNiL][CIO,],-H,O (&, = I ) of a dinucleating macrocycle H2L, derived from the [2: 1 : 13 condensation of 2,6-diformyl-4-methyIphenol, 1,2-diaminoethane and 1,4-diarninobutane, has been obtained. The efflorescent dimethylformamide (dmf) adduct [CuNiL][C10,],-H20~2dmf crystallizes in the orthorhombic crystal system, space group P2,2,2, with Z = 4, a = 15.62(1), b = 16.49(1) and c = 14.75(1) A. Crystallographic refinement converged with R = 0.060 and R' = 0.048 for 2958 reflections having I > 3.00o(I). The structure comprises [CuNiL(dmf)(H2O)l2 + where the two metal ions are bridged by the endogenous phenolic oxygens of the macrocycle and Cu 9 Ni is 3.038(2) A. The Cu resides at a N 2 0 2 site with an ethylene lateral 7 Nun-SI units employed: pB z 9.27 x lopz4 J T-', G =

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