FEATURES OF A FLEXIBLE BACKBONE IN THE COORDINATION COMPOUNDS OF A DIOXIME LIGAND: THE CHARACTERIZATION OF SUPRAMOLECULAR AND DINUCLEAR METAL COMPLEXES

Tetranuclear copper(II) complex of 2-hydroxy-N,N′-bis[1-(2-hydroxyphenyl)ethylidene]propane-1,3-diamine

In the title Schiff base tetra­nuclear copper(II) complex, two discrete environments are present in the structure: CuNO₄ and CuNO₃. Two copper(II) cations are situated in distorted square-pyramidal environment, while two copper(II) cations are located in a slightly square-planar geometry. One bridging acetate group acting in an η¹:η¹-μ₂-mode connects two copper(II) ions, while another bridging acetate group connects three copper(II) ions in an η¹:-η²–μ₃-mode.

The title mol­ecular structure, namely, (μ₃-acetato)(μ₂-acetato)­bis­(μ₃-1,3-bis­{[1-(2-oxidophen­yl)ethyl­idene]amino}­propan-2-olato)tetra­copper(II) monohydrate, [Cu₄(C₁₉H₁₉N₂O₃)₂(CH₃CO₂)₂]·H₂O, corresponds to a non-symmetric tetra­nuclear copper complex. The complex exhibits one ligand mol­ecule that connects two copper Cu^II metal centres via its ethano­lato oxygen anion acting in a μ₂-mode and one ligand mol­ecule that connects three copper Cu^II metal centres via its ethano­lato oxygen anion acting in a μ₃-mode. One bridging acetate group acting in an η¹:η¹-μ₂-mode connects two copper(II) ions while another bridging acetate group connects three copper(II) ions in an η¹:-η²-μ₃-mode. A chair-like Cu₃O₃ structure is generated in which the two CuO₄N units are connected by one μ₂-O ethano­late oxygen atom. These two units are connected respectively to the CuO₃N unit via one μ₃-O ethano­late oxygen atom and one μ₂-O atom from an acetate group. The μ₃-O atom also connects one of the CuO₄N units and the CuO₃N unit to another CuO₃N unit, which is out of the chair-like structure. Each of the two penta­coordinated Cu^II cations has a distorted NO₄ square-pyramidal environment. The geometry of each of the two CuNO₃ units is best described as a slightly square-planar environment. A series of intra­molecular O—H⋯O hydrogen bonds is observed. In the crystal, the units are connected by inter­molecular C—H⋯O and O—H⋯O hydrogen bonds, thus forming sheets parallel to the ac plane

Structure and Properties of Dinuclear Manganese(III) Complexes with Pentaanionic Pentadentate Ligands Including Alkoxo, Amido, and Phenoxo Donors

Doubly bridged mu-alkoxo-mu-X (X = pyrazolato or acetato) dinuclear MnIII complexes of 2-hydroxy-N-{2-hydroxy-3-[(2-hydroxybenzoyl)amino]propyl}benzamide) (H5L1) and 2-hydroxy-N-{2-hydroxy-4-[(2-hydroxybenzoyl)amino]butyl}benzamide (H5L2), [Mn2(L)(pz)(MeOH)4].xMeOH (1, L = L1, x = 0.5; 2, L = L2, x = 0; Hpz = pyrazole) and [Mn2(L1)(OAc)(MeOH)4] (3), have been prepared, and their structure and magnetic properties have been studied. The X-ray diffraction analysis of 1 (C24.5H34Mn2N4O9.5, triclinic, P, a = 12.2050(7) A, b = 12.7360(8) A, c = 19.2780(10) A, alpha = 99.735(5) degrees , beta = 96.003(4) degrees , gamma = 101.221(5) degrees , V = 2867.6(3) A3, Z = 4), 2 (C25H34Mn2N4O9, triclinic, P, a = 9.4560(5) A, b = 11.0112(5) A, c = 13.8831(6) A, alpha = 90.821(4) degrees , beta = 92.597(4) degrees , gamma = 93.403(4) degrees , V = 1441.29(12) A3, Z = 2), and 3 (C23H32Mn2N2O11, triclinic, P, a = 10.511(5) A, b = 11.713(5) A, c = 13.135(5) A, alpha = 64.401(5) degrees , beta = 74.000(5) degrees , gamma = 66.774(5) degrees , V = 1329.3(10) A3, Z = 2) revealed that all complexes consist of dinuclear units which are further extended into 1D (1 and 3) and 2D (2) supramolecular networks via hydrogen-bonding interactions. Magnetic susceptibility data evidence antiferromagnetic interactions for all three complexes: J = -3.6 cm-1, D approximately 0 cm-1, g = 1.93 (1); J = -2.7 cm-1, D = 0.8 cm-1, g = 1.93 (2); J = -4.9 cm-1, D = 3.8 cm-1, g = 1.95 (3).