Redetermination of bis{[(2‐hydroxy­phenyl­methyl)­bis(2‐pyridyl­methyl)­aminato]copper(II)} diperchlorate

The structure of the title compound, [Cu₂(C₁₉H₁₈N₃O)₂](ClO₄)₂, was reported with insufficient accuracy because of a twinning problem by Adams, Bailey, Campbell, Fenton & He [J. Chem. Soc. DaltonTrans. (1996), pp. 2233–2237]. The dinuclear phenolate‐bridged Cu^II complex has an inversion centre.     

Di‐μ‐hydroxo‐bis{(aceto­nitrile)dibenzyl(6‐methyl‐2‐pyridylmethyl)amine‐κ2N,N]copper(II)} bis(perchlorate)

The title compound corresponds to a copper(II) dimer, [Cu₂(OH)₂(C₂H₃N)₂(C₂₁H₂₂N₂)₂](ClO₄)₂, where the metal centres are μ₂‐bridged by hydroxo groups. The coordination of each copper(II) centre is a slightly distorted square‐based pyramid, with two N atoms from dibenzyl(6‐methyl‐2‐pyridylmethyl)amine (BiBzMePMA) and two hydroxo O atoms occupying the basal positions, and the aceto­nitrile N atom at the apical position. The dimer is centrosymmetric, with a crystallographic inversion centre midway between the two Cu atoms [Cu⋯Cu = 2.9522 (9) Å]     

Tetrakis(μ‐benzoato‐κ2O:O)bis{[4‐(dimethylamino)pyridine‐κN1]copper(II)}

The title compound, [Cu₂(C₇H₅O₂)₄(C₇H₁₀N₂)₂], is a crystallographically centrosymmetric binuclear complex, with Cu atoms [Cu...Cu = 2.6982 (4) Å] bridged by four benzoate ligands. Each of the Cu atoms in this bunuclear copper(II) acetate hydrate analogue is present in an approximately square‐pyramidal environment, with four O atoms in a plane and the pyridine N atom at the apical site. Selected geometric parameters are compared with values for related tetrabenzoate complexes of copper(II).     

μ‐Oxo‐bis{[(6‐hydroxy­methyl‐2‐pyridyl­methyl)­bis(2‐pyridyl­methyl)­amine‐κ5N,N′,N′′,N′′′,O]­iron(III)} tetrakis­(perchlorate)

The novel μ‐oxo‐diiron complex [Fe₂O(BPHPA)₂](ClO₄)₄ [BPHPA is (6‐hydroxy­methyl‐2‐pyridyl­methyl)­bis(2‐pyridyl­methyl)­amine, C₁₉H₂₀N₄O], contains a binuclear centrosymmetric [Fe₂O(BPHPA)₂]⁴⁺ cation (the bridging O atom lies on an inversion centre) and four perchlorate anions. Each iron ion is coordinated by four N atoms [Fe—N = 2.117 (5)–2.196 (5) Å] and one O atom [Fe—O = 2.052 (5) Å] from a BPHPA ligand, and by one bridging oxo atom [Fe—O = 1.7896 (9) Å], forming a distorted octahedron. There are hydrogen bonds between the hydroxy group and perchlorate O atoms [O—H·O = 2.654 (7) Å].     

Di‐μ‐hydroxido‐bis{[bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine‐κ3N′,N′′,N′′′]copper(II)} bis(perchlorate)

The title compund, [Cu₂(OH)₂(C₂₂H₂₅N₃)₂](ClO₄)₂, is a copper(II) dimer, with two [CuL]²⁺ units [L is bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine] bridged by hydroxide groups to define the {[CuL](μ‐OH)₂[CuL]}²⁺ cation. Charge balance is provided by perchlorate counter‐anions. The cation has a crystallographic inversion centre halfway between the Cu^II ions, which are separated by 3.0161 (8) Å. The central core of the cation is an almost regular Cu₂O₂ parallelogram of sides 1.931 (2) and 1.935 (2) Å, with a Cu—O—Cu angle of 102.55 (11)°. The coordination geometry around each Cu^II centre can be best described as a square‐based pyramid, with three N atoms from L ligands and two hydroxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide–perchlorate O—H...O interactions.     

[N′‐Benzoyl‐N,N‐bis(2‐pyridylmethyl‐κN)­ethyl­enedi­amine‐κN]chloro­copper(II) hexa­fluoro­phosphate

The title mononuclear copper(II) complex, [CuCl(C₂₁H₂₂­N₄O)]­PF₆, shows a distorted square‐planar coordination and the benzoyl­amino N atom does not coordinate to the Cu atom.     

Chloro­[N′,N′‐diethyl‐N,N‐bis(2‐pyri­dyl­methyl)­ethyl­enedi­amine‐κ4N]copper(II) perchlorate

The title mononuclear copper(II) complex, [CuCl(C₁₈H₂₆N₄)]ClO₄, shows a square‐pyramidal coordination with the diethyl­amino N atom at the apical position. Large anisotropies in the displacement parameters of the non‐H atoms of the ligand seem to be due to rotational disorder of the ClO₄^? anion.     

Bis{μ‐[6‐(hydroxy­methyl)‐2‐pyridyl]­methano­lato‐κ3N,O:O}bis{[2,6‐bis­(hydroxy­methyl)­pyridine‐κ3O,N,O′]copper(II)} di­acetate

The title dinuclear Cu^II complex, [Cu₂(C₇H₈NO₂)₂(C₇H₉NO₂)₂](CH₃COO)₂, has been synthesized by the reaction of Cu(CH₃COO)₂·H₂O with pdmH₂ (pdmH₂ is pyridine‐2,6‐diyldi­methanol) in the presence of tetra­butyl­ammonium hydro­xide. The title complex contains a centrosymmetric Cu₂O₂ core and each Cu^II atom has distorted octahedral geometry. Molecular [Cu₂(pdmH)₂(pdmH₂)]²⁺ cations are connected by hydrogen bonds involving the CH₃COO⁻ anions, forming one‐dimensional chains along the a axis.     

(1,3‐Dimethylimidazolidine‐2‐selone‐κSe)bis(1,10‐phenanthroline‐κ2N,N′)copper(II) bis(perchlorate) and bis(2,2′‐bipyridyl‐κ2N,N′)(imidazolidine‐2‐thione‐κS)copper(II) bis(perchlorate)

In the first title salt, [Cu(C₁₂H₈N₂)₂(C₅H₁₀N₂Se)](ClO₄)₂, the Cu^II centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10‐phenanthroline (phen) ligands and by the Se donor of a 1,3‐dimethylimidazolidine‐2‐selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) Å and the Cu—Se distance is 2.491 (3) Å. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C₁₀H₈N₂)₂(C₃H₆N₂S)](ClO₄)₂, the Cu^II centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′‐bipyridyl (bipy) ligands and an S donor from an imidazolidine‐2‐thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) Å and the Cu—S distance is 2.366 (3) Å. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H...O hydrogen bonds linking the imidazolidine N—H hydrogen‐bond donors to perchlorate O‐atom acceptors.     

On the short carbonyl bond in bis[μ‐1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxido‐κ2N:O]bis{[1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxido‐κN]bis(imidazole)copper(II)}

The short carbonyl bond in the title compound, [Cu₂(C₇H₄­NO₃S)₄(C₃H₄N₂)₄] [Liu, Huang, Li & Lin (1991). Acta Cryst. C 47 , 41–43], is an artifact of disorder in the iso­thia­zol‐3(2H)‐one 1,1‐dioxide part of the 1,2‐benziso­thia­zol‐3(2H)‐one entity. In the present redetermination, all bond dimensions in the centrosymmetric dinuclear mol­ecule are normal. The five‐coordinate Cu atom shows trigonal–bipyramidal coordination. Hydro­gen bonds from the imidazole donor ligand link adjacent mol­ecules into a two‐dimensional layer structure.     

Hexa‐μ‐chloro‐μ4‐oxo‐tetrakis{[5‐(2,4,6‐trimethylphenyl)pyrazole‐κN2]copper(II)}

The title compound, [Cu₄Cl₆O(C₁₂H₁₄N₂)₄], is a new example of the well known [Cu₄(μ₄‐O)(μ‐X)₆L₄] class of complex (X⁻ is Cl⁻, Br⁻ or I⁻, and L is a monodentate ligand). The molecule has crystallographic C₂ symmetry, with two Cl⁻ ions on each edge of a Cu₄ tetrahedron. Two of these, on opposite edges of the tetrahedron, accept intramolecular hydrogen bonds from two of the pyrazole N—H donors.     

Di‐μ‐hydroxo‐bis({bis­[2‐(2‐pyridyl)ethyl]amine‐κ3N}copper(II)) dichloride hexahydrate

The title compound, [Cu₂(OH)₂(C₁₄H₁₇N₃)₂]Cl₂·6H₂O, is a crystallographically centrosymmetric dimer of square‐pyramidal Cu^II centres, with a basal–basal [Cu₂(μ‐OH)₂]²⁺ bridging motif and apical pyridyl donors. The Cl⁻ anion is hydrogen bonded to one O—H and one N—H group, and to three different water mol­ecules. Because of disorder, the network of intramolecular hydrogen bonding in the hydrated lattice is only partly resolved.     

Di­chloro­bis(2‐chloro‐5‐methyl­pyridine‐κN)copper(II)

In the crystals of the title compound, [CuCl₂(C₆H₆ClN)₂], the Cu atom lies on an inversion centre and is four‐coordinated by two pyridine N atoms and two Cl atoms in trans positions. The coordination geometry is square planar, with Cu—N and Cu—Cl distances of 1.986 (2) and 2.2536 (11) Å, respectively. The two pyridine rings are parallel, but twist from the CuN₂Cl₂ coordination plane by about 95° in the complex mol­ecule. There are three kinds of intermolecular C—H⃛Cl hydrogen bonds in the crystals. Two of these types generate two‐dimensional molecular networks, viewed in the direction of the a axis, and the other connects adjacent molecular networks.     

Bis­[1,3‐bis(2‐methyl­tetrazol‐5‐yl‐κN4)­triazenido‐κN2]­nickel(II)

The title compound, [Ni(BMTT)₂], where BMTT is 1,3‐bis(2‐methyl­tetrazol‐5‐yl)­triazenide (C₄H₆N₁₁), presents a molecular complex with tridentate ligands. The tridentate mode of the ligand is realised through the central N atom of the triazene group and two N atoms of the two tetrazole rings. The [Ni(BMTT)₂] mol­ecule is the meridional isomer, with crystallographic symmetry in space group P4₂/n. The nickel centre has a distorted octahedral environment, with two axial Ni—N bonds of 2.041 (2) Å and four equatorial Ni—N bonds of 2.0739 (14) Å. The mol­ecules are linked together by van der Waals interactions only.     

Di­bromo(N,N′‐di‐2‐pyridyl­amine‐κ2N,N′)­palladium(II)

The palladium center of the title compound, [PdBr₂(C₁₀H₉N₃)], has a slightly distorted square‐planar conformation, with the Pd atom bonded to the two pyridine N atoms of the di‐2‐pyridyl­amine moiety and to two Br atoms. The Pd—Br and Pd—N bond lengths are 2.4168 (6)/2.4201 (5) and 2.036 (3)/2.042 (3) Å, respectively.     

Synthesis and crystal structure of the dinuclear copper(II) Schiff base complex μ‐hydroxido‐μ‐chlorido‐bis{[bis(trans‐2‐nitrocinnamaldehyde)ethylenediamine]chloridocopper(II)} dichloromethane sesquisolvate

Transition metal complexes of Schiff base ligands have been shown to have particular application in catalysis and magnetism. The chemistry of copper complexes is of interest owing to their importance in biological and industrial processes. The reaction of copper(I) chloride with the bidentate Schiff base N,N′‐bis(trans‐2‐nitrocinnamaldehyde)ethylenediamine {Nca₂en, systematic name: (1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis[3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]} in a 1:1 molar ratio in dichloromethane without exclusion of air or moisture resulted in the formation of the title complex μ‐chlorido‐μ‐hydroxido‐bis(chlorido{(1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis[3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]‐κ²N,N′}copper(II)) dichloromethane sesquisolvate, [Cu₂Cl₃(OH)(C₂₀H₁₈N₄O₄)₂]·1.5CH₂Cl₂. The dinuclear complex has a folded four‐membered ring in an unsymmetrical Cu₂OCl₃ core in which the approximate trigonal bipyramidal coordination displays different angular distortions in the equatorial planes of the two Cu^II atoms; the chloride bridge is asymmetric, but the hydroxide bridge is symmetric. The chelate rings of the two Nca₂en ligands have different conformations, leading to a more marked bowing of one of the ligands compared with the other. This is the first reported dinuclear complex, and the first five‐coordinate complex, of the Nca₂en Schiff base ligand. Molecules of the dimer are associated in pairs by ring‐stacking interactions supported by C—H…Cl interactions with solvent molecules; a further ring‐stacking interaction exists between the two Schiff base ligands of each molecule.     

Di­chloro­tetrakis(3‐phenyl­pyrazole‐κN2)copper(II)

In the title compound, [CuCl₂(C₉H₈N₂)₄], there are two independent mol­ecules in the asymmetric unit. The Cu²⁺ ions lie on inversion centres and are octahedrally coordinated by two Cl atoms and four pyrazole N atoms. All pyrazole N—H groups form intramolecular hydrogen bonds, giving rise to five‐membered hydrogen‐bonded rings incorporating the Cu atoms.     

Hemi[hexa­aqua­magnesium(II)] (μ‐2,6‐bis{[bis­(carboxyl­ato­methyl)­amino]­methyl}‐4‐chloro­phenolato)­bis­[di­aqua­magnesium(II)] decahydrate

The crystal structure of the title compound, [Mg(H₂O)₆]_0.5[Mg₂(C₁₆H₁₄ClN₂O₉)(H₂O)₄]·10H₂O, shows that this bi­nuclear complex consists of two Mg centres in distorted octahedral geometry, joined by an oxo bridge which is a derivative of the deprotoned hydroxy group of the phenolate in the ligand mol­ecule. In the anion, the coordination sphere of each Mg^II ion is completed by two carboxyl­ates, a tertiary N atom and two water mol­ecules. The inner coordination spheres for the Mg^II ions are very similar, both in ligand sets and in geometry. Each unit of the binuclear complex has one negative charge neutralized by a neighbouring hydrated cation, [Mg(H₂O)₆]²⁺, in which the Mg atom lies on an inversion centre. In each cell, there are 34 water mol­ecules and most of them participate in the formation of hydrogen bonds, which contribute greatly to the stability of the whole structure.