Conformational and stereochemical flexibility in cadmium(II) complexes of aza-thioether macrocycles.

The synthesis and crystal structures of four CdII macrocyclic complexes containing mixed N-, O- and S-donors, [Cd(NO3)2([12]aneN2S2)] (1), [Cd(NO3)2([12]aneNS3)] (2), [Cd(NO3)2([15]aneNO2S2)] (3) and [Cd(NO3)([15]aneN2O2S)]NO3 (4), are presented. The metal ion is coordinated outside of the macrocyclic cavity in the complexes of the smaller macrocycles ([12]aneN2S2 and [12]aneNS3) while the flexibility of the larger macrocycles in and allows very different conformations to be adopted with a 'butterfly' geometry in and a flattened geometry in. No correlation between the number of sulfur donors and Cd-S bond distance in these types of complexes is observed, although the number and binding mode of the nitrato ligands is determined by the conformation and binding mode of the macrocycle.

Century-known copper salt Cu(OAc)(OMe) proven to be a unique magnetic lattice composed of tetranuclear copper(II) species with a rare binding mode of the acetate anion.

The structure, spectroscopy, and magnetism of a century-old copper salt, Cu(OAc)(OMe), is reported. The crystal structure contains two independent Cu(II) ions, which are both five-coordinated and which are bridged by methoxo and acetate anions to form an infinite 2D network. Thereby the methoxo groups connect Cu1 and Cu2 with their symmetry-generated counterparts Cu1(i) and Cu2(i), respectively, resulting in Cu.

An unprecedented 1D ladder coordination polymer based on a pentanuclear copper(II) 2,4,6-tris(dipyridin-2-ylamino)-1,3,5-triazine building block.

Copper(II) nitrate reacts with the rigid polydentate triple-connecting dpyatriz ligand in acetonitrile to an unprecedented infinite molecular ladder in which five-coordinated copper pseudo-dimer are bridged by nitrate anions and the coordination polymer chains are linked by hexacoordinated copper ions leading to the formation of large guest cavities.

A solvent-controlled switch of manganese complex assemblies with a beta-diketonate-based ligand.

The coordination properties of the new polynucleating ligand H(3)L1 (1,3-bis(3-oxo-3-phenylpropionyl)-2-hydroxy-5-methylbenzene) with Mn(II/III) are described. Depending on the solvent used, the reaction of H(3)L1 with Mn(OAc)(2) yields either of the two new multinuclear assemblies [Mn(2)(HL1)(2)(py)(4)] (1) and [Mn(3)(HL1)(3)] (2), as revealed by X-ray crystallography. The structure of 2 is remarkable in that it shows a unique asymmetric triple-stranded helicate.

Formation of Dinuclear Copper(II) Complexes from a Macrocycle with Built-in Pyrazole Groups.

The 22-membered macrocycle, containing four endocyclic pyrazole groups and two exocyclic pyridine groups, viz. (9,22-di(pyridin-2-ylmethyl)-1,4,9,14,17,22,27,28,29,30-decaaza-5,13,18,26-tetramethyl)pentacyclo[24.2.

Dinuclear Paddle-Wheel Copper(II) Carboxylates in the Catalytic Oxidation of Carboxylic Acids. Unusual Polymeric Chains Found in the Single-Crystal X-ray Structures of [Tetrakis(&mgr;-1-phenylcyclopropane-1-carboxylato-O,O')bis(ethanol-O)dicopper(II)] and catena-Poly[[bis(&mgr;-diphenylacetato-O:O')dicopper](&mgr;(3)-diphenylacetato-1-O:2-O':1'-O')(&mgr;(3)-diphenylacetato-1-O:2-O':2'-O')].

The X-ray structures and spectroscopic and magnetic properties of [tetrakis(&mgr;-1-phenylcyclopropane-1-carboxylato-O,O')bis(ethanol-O)dicopper(II)], 1, and catena-poly[[bis(&mgr;-diphenylacetato-O:O')dicopper](&mgr;(3)-diphenylacetato-1-O:2-O':1'-O')(&mgr;(3)-diphenylacetato-1-O:2-O':2'-O')], 2, two extended-chain copper(II) carboxylates with dinuclear paddle-wheel subunits, are reported. 1 crystallizes in the triclinic space group P&onemacr;, with a = 6.8873(3) Å, b = 11.

High Superoxide Dismutase Activity of a Novel, Intramolecularly Imidazolato-Bridged Asymmetric Dicopper(II) Species. Design, Synthesis, Structure, and Magnetism of Copper(II) Complexes with a Mixed Pyrazole-Imidazole Donor Set.

A new dinucleating ligand, 1,5-bis(1-pyrazolyl)-3-[bis(2-imidazolyl)methyl] azapentane (Hbpzbiap), containing pyrazoles and imidazoles has been designed and synthesized. The synthesis and characterization of the copper complexes with the ligand Hbpzbiap and its dehydronated form are described. This study is aimed at modeling the active site of copper-zinc superoxide dismutase (SOD).

Synthesis, Characterization, and Single-Crystal EPR Studies of Three Dinuclear Copper(II) Complexes and One Mixed-Valence Tetranuclear Copper(I)-Copper(II) Cluster with an Asymmetric Imidazole-Containing Tripodal Ligand with Copper(II)-Copper(II) Distances between 3.35 and 3.63 Å.

The synthesis and characterization of three dinuclear copper(II) complexes and one mixed-valence tetranuclear cluster with the asymmetric imidazole-containing ligand bis(1,1'-imidazole-2-yl)(4-imidazole-4(5)-yl)-2-azabutane (biib) are described. X-ray crystallographic parameters for the copper complexes are as follows. [Cu(2)(biib)(2)(BF(4))(2)](BF(4))(2)(H(2)O)(4): triclinic, space group P&onemacr;, a = 10.