A self-assembled octanuclear complex bearing the uncommon close-packed {Fe4Mn4(μ4-O)4(μ-O)4} molecular core.

A one-pot open-air reaction of manganese powder with iron(ii) chloride in DMF solution of the Schiff base (H2L) formed in situ from salicylaldehyde and hydroxylamine hydrochloride yields the heterometallic complex [Fe4(μ4-O)4Mn4(L)8(DMF)4]·2DMF (). Single crystal X-ray analysis shows that its molecular structure is based on the octanuclear core {Fe4Mn4(μ4-O)4(μ-O)4} with a quite rare molecular structure type {M8(μ4-X)4(μ-X)4}, where the central cube-like iron motif is modified with four terminal manganese fragments, the whole core being presented as the {Fe4(μ4-O)4} + 4{Mn(μ-O)} combination. Using the data from the Cambridge Structural Database (CSD), an analysis of the octanuclear structures with similar central {M4(μ4-X)4} fragments was performed.

Direct synthesis of a {Co₆(III)Fe₆(III)} dodecanuclear complex, revealing an unprecedented molecular structure type.

A novel heterometallic Co6Fe6 Schiff base complex, possessing an unprecedented {M12(μ-X)22} branched structure (according to the search via the Cambridge Structural Database), has been prepared using the "direct synthesis" approach and characterized by single crystal X-ray diffraction and magnetometry.

Tetra-kis(μ3-2-{[1,1-bis-(hy-droxy-meth-yl)-2-oxidoeth-yl]imino-meth-yl}-6-nitro-pheno-lato)tetra-copper(II).

The title cluster, [Cu4(C11H12N2O6)4], was obtained from the Cu(0)-FeCl2·4H2O-H4 L-Et3N-DMF reaction system (in air), where H4 L is 2-hy-droxy-methyl-2{[(2-hy-droxy-3-nitro-phen-yl)methyl-idene]amino}-propane-1,3-diol and DMF is di-methyl-formamide. The asymmetric unit consists of one Cu(2+) ion and one dianionic ligand; a -4 symmetry element generates the cluster, which contains a {Cu4O4} cubane-like core. The metal ion has an elongated square-based pyramidal CuNO4 coordination geometry with the N atom in a basal site.

Magnetic, high-field EPR studies and catalytic activity of Schiff base tetranuclear CuII2FeIII2 complexes obtained by direct synthesis.

Two novel heterometallic complexes [Cu2Fe2(HL(1))2(H2L(1))2]·10DMSO (1) and [Cu2Fe2(HL(2))2(H2L(2))2]·2DMF (2) have been prepared using the open-air reaction of copper powder, iron(II) chloride and DMSO (1) or DMF (2) solutions of the polydentate Schiff base (H4L(1), 1; H4L(2), 2) formed in situ from salicylaldehyde (1) or 5-bromo-salicylaldehyde (2) and tris(hydroxymethyl)aminomethane. Crystallographic analysis revealed that both compounds are based on the centrosymmetric tetranuclear core {Cu(II)2Fe(III)2(μ-O)6} where metal centres are joined by μ-O bridges from the deprotonated ligands forming a nonlinear chain-like arrangement. Variable-temperature (1.

Heterometallic Co(III)4Fe(III)2 Schiff base complex: structure, electron paramagnetic resonance, and alkane oxidation catalytic activity.

The heterometallic complex [Co(4)Fe(2)OSae(8)]·4DMF·H(2)O (1) was synthesized by one-pot reaction of cobalt powder with iron chloride in a dimethylformamide solution of salicylidene-2-ethanolamine (H(2)Sae) and characterized by single crystal X-ray diffraction analysis, magnetic measurements, high frequency electron paramagnetic resonance (HF-EPR), and Mössbauer spectroscopies. The exchange coupling in the Fe(III)-Fe(III) pair is of antiferromagnetic behavior with J/hc = -190 cm(-1). The HF-EPR spectra reveal an unusual pattern with a hardly detectable triplet signal of the Fe(III) dimer.

Bis(μ-4-nitro-2-{[2-(oxidometh-yl)phen-yl]imino-meth-yl}phenolato)bis-[chlorido(dimethyl sulfoxide)-iron(III)] dimethyl sulfoxide disolvate.

In the centrosymmetric dimeric title complex, [Fe(2)(C(14)H(10)N(2)O(4))(2)Cl(2)(C(2)H(6)OS)(2)]·2C(2)H(6)OS, two {Fe(L)Cl(DMSO)} units (L is the tridentate ligand 4-nitro-2-{[2-(oxidometh-yl)phen-yl]imino-meth-yl}phenolate; DMSO is dimethyl sulfoxide) are bridged by two O atoms, with an Fe⋯Fe separation of 3.1838 (8) Å. The coordination polyhedron of the Fe(III) atoms can be described as distorted octa-hedral, with four Fe-O, one Fe-N and one Fe-Cl coordination bonds.

Tris(2,2'-bipyridine-κN,N')cobalt(III) tris-(oxalato-κO,O)ferrate(III) mono-hydrate.

The title compound, [Co(C(10)H(8)N(2))(3)][Fe(C(2)O(4))(3)]·H(2)O, con-sists of two discrete tris-(chelate) metal ions (Co(III)N(6) and Fe(III)O(6) chromophores) and a water mol-ecule. The structure is highly symmetrical; the Co(III) and Fe(III) ions occupy positions with site symmetry 3.2.

Hexa-kis-(dimethyl-formamide-κO)manganese(II) μ-oxido-bis-[trichlorido-ferrate(III)].

The title compound, [Mn(C(3)H(7)NO)(6)][Fe(2)Cl(6)O], was obtained unintentionally as a product of an attempted synthesis of heterometallic complexes with Schiff base ligands using manganese powder and FeCl(3)·6H(2)O as starting materials. In the [Fe(2)OCl(6)](2-) anion, the O atom and the Fe atom occupy positions with site symmetry [Formula: see text] and 3, respectively, resulting in a linear Fe-O-Fe angle and a staggered conformation. The octa-hedrally surrounded cation (site symmetry [Formula: see text]) and the [Fe(2)Cl(6)O](2-) anion are alternately stacked along [001].

Novel heterometallic Schiff base complexes featuring unusual tetranuclear {Co(III)2Fe(III)2(μ-O)6} and octanuclear {Co(III)4Fe(III)4(μ-O)14} cores: direct synthesis, crystal structures, and magnetic properties.

A one-pot reactions of cobalt powder with iron(II) chloride in dimethylformamide (DMF; 1) or dimethyl sulfoxide (DMSO; 2) solutions of polydentate salicylaldimine Schiff base ligands (H(2)L(1), 1; H(4)L(2), 2) based on 2-aminobenzyl alcohol (1) or tris(hydroxymethyl)aminomethane (2), formed in situ, yielded two novel heterometallic complexes, [Co(III)(2)Fe(III)(2)(L(1))(6)]·4DMF (1) and [Co(III)(4)Fe(III)(4)(HL(2))(8)(DMSO)(2)]·18DMSO (2). Crystallographic investigations revealed that the molecular structure of 1 is based on a tetranuclear core, {Co(III)(2)Fe(III)(2)(μ-O)(6)}, with a chainlike metal arrangement, while the structure of 2 represents the first example of a heterometallic octanuclear core, {Co(III)(4)Fe(III)(4)(μ-O)(14)}, with a quite rare manner of metal organization, formed by two pairs of {CoFe(HL(2))(2)} and {CoFe(HL(2))(2)(DMSO)} moieties, which are joined by O bridges of the Schiff base ligands. Variable-temperature (1.

Triethyl-ammonium bis-{2-[(2-oxido-5-nitro-benzylidene)amino]-benzoato}ferrate(III) monohydrate.

In the title compound, [NH(C(2)H(5))(3)][Fe(C(14)H(8)N(2)O(5))(2)]·H(2)O, the iron(III) ion is hexa-coordinated by four O atoms in the basal plane [Fe-O distances in the range 1.904 (4)-1.909 (4) Å] and two N atoms in the axial plane [Fe-N = 1.