Mn and Ce Units Supported on an Octahedral Molecular Nanoparticle of CeO.

The preparation of three new heterometallic clusters [CeMnO(OCPh)] (), [CeMnO(OCPh)] (), and [CeMnO(OH)(tbb)(HO)](NO) (; tbb = 4-Bu-benzoate) is reported. They all possess unprecedented structures with a common feature being the presence of an octahedral Ce-oxo core: a Ce in , two edge-fused Ce giving a Ce bioctahedron in , or a larger Ce octahedron in . Complex is the first Ce cluster with a central μ-O.

Molecular analogue of the perovskite repeating unit and evidence for direct Mn-Ce-Mn exchange coupling pathway.

The perovskite manganites AMnO and their doped analogues A B MnO (A and B = main group and lanthanide metals) are a fascinating family of magnetic oxides exhibiting a rich variety of properties. They are thus under intense investigation along multiple fronts, one of which is how their structural and physical properties are modified at the nanoscale. Here we show that the molecular compound [CeMnO(OCPh)(HOCPh)] (CeCeMn; hereafter CeMn) bears a striking structural resemblance to the repeating unit seen in the perovskite manganites.

Heterometallic MnLn (Ln = Dy, Gd, Tb) Cross-Shaped Clusters and Their Homometallic MnMn Analogues.

The employment of di-2-pyridyl ketone, (py)CO, in heterometallic Mn/4f and homometallic Mn cluster chemistry has yielded six MnLn and two MnMn structurally related clusters, namely, [MnLnO{(py)CO}(NO)(RCO)(HO)](NO) (Ln = Gd, 1, 5; Dy, 2; Tb, 3; R = Et, 1-3; Me, 5), [MnDyO{(py)CO}(NO)(EtCO)(HO)(MeOH)]·0.7MeOH·0.8HO (4·0.

Crystal structure of -poly[bis-(tetra-ethyl-ammonium) [tetra-aqua-tris(μ-dicyanamido-κ:)bis(dicyanamido-κ)di-cobaltate(II)] dicyanamide].

The structure of the title compound, [N(CH)][Co(CN)(HO)](CN), is a new example of a metal-dicyanamide coordination polymer which exhibits a unique three-dimensional framework of covalently linked Co chains. All bridging dicyanamide ligands in the title structure are in the -bridging mode. The anionic Co-dicyanamide network is templated by tetra-ethyl-ammonium cations residing in a series of channels extending along the axis where additional non-coordinating dicyanamidate anions are also located.

Co, Co, and a Series of CoLn (Ln = Nd, Sm, Gd, Tb, Dy) Coordination Clusters: Search for Single Molecule Magnets.

We report herein the syntheses and investigation of the magnetic properties of a Co compound, a series of trinuclear CoLn (Ln = Nd, Sm, Gd, Tb, Dy) complexes, and a Co complex. The homometallic Co core was obtained from the reaction of Ln(NO)·xHO/Co(NO)·6HO/Hvab/EtN in a 0.5:0.

Unusual Mn(III/IV)4 Cubane and Mn(III)16M4 (M = Ca, Sr) Looplike Clusters from the Use of Dimethylarsinic Acid.

Three complexes are reported from the initial use of dimethylarsinic acid (Me2AsO2H) in Mn(III/IV) cluster chemistry, [Mn4O4(O2AsMe2)6] (3; 2Mn(III), 2Mn(IV)), and [Mn16X4O8(O2CPh)16(Me2AsO2)24] (X = Ca(2+) (4) or Sr(2+) (5); 16Mn(III)). They were obtained from reactions with [Mn12O12(O2CR)16(H2O)4] (R = Me, Ph) either without (3) or with (4 and 5) the addition of X(2+) salts. Complex 3 contains a [Mn4O4](6+) cubane, whereas isostructural 4 and 5 contain a planar loop structure comprising four Mn4 asymmetric "butterfly" units linked by alternating anti,anti μ-O2AsMe2 and {X2(O2AsMe2)(O2CPh)2} units.

Crystal structure of catena-poly[[(dimethyl sulfoxide-κO)(pyridine-2,6-di-carboxyl-ato-κ(3) O,N,O')nickel(II)]-μ-pyrazine-κ(2) N:N'].

The title coordination polymer, [Ni(C7H3NO4)(C4H4N2)(C2H6OS)] n , consists of [010] chains composed of Ni(II) ions linked by bis-monodentate-bridging pyrazine mol-ecules. Each of the two crystallographically distinct Ni(II) ions is located on a mirror plane and is additionally coordinated by a dimethyl sulfoxide (DMSO) ligand through the oxygen atom and by a tridentate 2,6-pyridine-di-carb-oxy-lic acid dianion through one of each of the carboxyl-ate oxygen atoms and the pyridine nitro-gen atom, leading to a distorted octa-hedral coordination environment. The title structure exhibits an inter-esting complementarity between coordinative bonding and π-π stacking where the Ni-Ni distance of 7.

Crystal structure of catena-poly[[[trans-bis(aceto-nitrile-κN)diaquacobalt(II)]-μ-pyrazine-κ(2) N:N'] dinitrate].

The central structural motif of the title coordination polymer, [Co(NO3)2(C4H4N2)(CH3CN)2(H2O)2] n , is a chain composed of Co(II) ions linked by bis-monodentate bridging pyrazine ligands through their N atoms. The Co(II) ion is located on an inversion center and is additionally coordinated by two O atoms of water mol-ecules and two N atoms of aceto-nitrile mol-ecules. The resultant N4O2 coordination sphere is distorted octa-hedral.

New structural types of Mn16 single-molecule magnets: W-shaped topology from reductive aggregation.

Two new Mn16 clusters are reported: [Mn16O10(OH)3(OMe)8(O2CPhBut)17(MeOH)5] (2) and [Mn16O16(OMe)6(O2CPh)12(NO3)4(MeOH)2(H2O)4] (3). The complexes were obtained by reductive aggregation of MnO4– in CH2Cl2/MeOH, and oxidation of MnII and preformed (NnBu4)[Mn4IIIO2(O2CPh)9(H2O)] with CeIV, respectively. The core of 2 has a Mn16III core with an unusual 1:2:3:4:3:2:1 layer structure and a W-shaped pleated topology, whereas 3 contains a central 2 × 3 Mn6IV planar grid held within a nonplanar Mn10III loop and is a rare example of a complex with nitrate ions bridging like carboxylate ions.

[Mn12O12(O2CMe)12(NO3)4(H2O)4]: facile synthesis of a new type of Mn12 complex.

The title dodecanuclear Mn complex, namely dodeca-μ(2)-acetato-κ(24)O:O'-tetraaquatetra-μ(2)-nitrato-κ(8)O:O'-tetra-μ(4)-oxido-octa-μ(3)-oxido-tetramanganese(IV)octamanganese(III) nitromethane tetrasolvate, [Mn(12)(CH(3)COO)(12)(NO(3))(4)O(12)(H(2)O)(4)]·4CH(3)NO(2), was synthesized by the reaction of Mn(2+) and Ce(4+) sources in nitromethane with an excess of acetic acid. This compound is distinct from the previously known single-molecule magnet [Mn(12)O(12)(O(2)CMe)(16)(H(2)O)(4)], synthesized by Lis [Acta Cryst. (1980), B36, 2042-2044].

Synthesis, characterization, and reactivity of iron(III) complexes supported by a trianionic ONO(3-) pincer ligand.

Synthetic and characterization results of a new family of Fe(III) compounds stabilized by a trianionic [CF3-ONO](3-) pincer-type ligand are reported. The ligand possesses three negatively charged donors constrained to the meridional positions that provide sufficient electron density to stabilize high-valent metal complexes. Using the redox-insulated [CF3-ONO](3-), pentacoordinated square-pyramidal {[CF3-ONO]FeCl2}{LiTHF2}2 (3), dimeric μ-DME{[CF3-ONO]FeDME}2 (4), trigonal bipyramidal [CF3-ONO]Fe(bpy) (5), and octahedral [CF3-ONO]Fe(bpy)H2O (5·H2O) complexes are synthesized.

Manganese/cerium clusters spanning a range of oxidation levels and CeMn(8), Ce(2)Mn(4), and Ce(6)Mn(4) nuclearities: structural, magnetic, and EPR properties.

The syntheses, structures, and magnetic properties are reported for three new Ce/Mn clusters with different Ce/Mn ratios: [Ce6Mn4O12(O2CMe)10(NO3)4(py)4] (py = pyridine) (1), [CeMn8O8(O2CCH2(t)Bu)12(DMF)14] (DMF = dimethylformamide) (2), and [Ce2Mn4O2(O2CMe)6(NO3)4(hmp)4] (3; hmp(-) is the anion of 2-(hydroxymethyl)pyridine). 1 and 2 were obtained from the reaction of Ce(IV) with [Mn12O12(O2CMe)16(H2O)4] (Mn(III)8Mn(IV)4) and [Mn8O2(O2CCH2(t)Bu)14((t)BuCH2CO2H)4] (Mn(II)6Mn(III)2), respectively, whereas 3 resulted from the oxidation of Mn(II) acetate with Ce(IV) in the presence of hmpH. Cluster 1 possesses an unusual [Ce6Mn4O12](14+) core topology consisting of a [Ce6O8] face-capped octahedron, which is face-fused at each end to a [Ce(IV)2Mn(III)Mn(IV)O4] cubane.

Supramolecular chains of high nuclearity {Mn(III)25} barrel-like single molecule magnets.

The first application of 1-methyl-1H-pyrrole-2-carbaldehyde oxime as a ligand for the coordination of paramagnetic transition metal ions has afforded a new {Mn(III)25} barrel-like cluster linked via Na(+) cations into a 1D polymeric topology that exhibits single-molecule magnetic behaviour.