UV/VIS Spectral Studies of Catecholase Activity of Binuclear Copper(II) Complexes [Cu2REP(μ-X)(Y)2]

By means of ultraviolet and visible spectroscopy we have studied the catecholase activity of two binuclear copper(II) complexes of general formula [Cu₂REP(u-X)(Y)₂] (1, X=OH and Y=ClO₄; 2, X=Y=CI), REP =deprotonated 2, 6-bis(1′-(4′-(2″-pyridyl)-2′-thiabutyl))-4-methylphenol. Both complexes promote catalytic autoxidation of 3, 5-di-tert-butylcatechol (3, 5-DTBC) to 3, 5-di-tert-butylquinone (3, 5-DTBQ) in methanol, but not in acetonitrile.     

Synthesis and magnetic properties of a new binuclear copper(II) complex with naphthalato-bridged ligand

To utilized a bridged-ligand of 1,8-naphthalate dianion (NAPH) as building block by self-assembly technology, a new binuclear copper(II) compound [Cu₂(μ-NAPH)₂(DMF)₄(H₂O)₂] (I) has been constructed and structurally characterized by X-ray crystallography. Complex I crystallizes in monoclinic, space group C2/c, with a = 17.822(9), b = 9.964(5), c = 23.194(11) Å and β = 102.385(5)°. Magnetic measurements confirm that I presents a very weak antiferromagnetic interaction between the paramagnetic ions.     

Mehrkernige Kobaltkomplexe. IV. Darstellung und Struktur von [(papd)Co(O2)Co(papd)](S2O6)(NO3)2 · 4 H2O1)

Polynuclear Cobalt Complexes. IV. Preparation and Structure of [(papd)Co(O₂)Co(papd)](S₂O₆)(NO₃)₂ · 4 H₂O The binuclear peroxo complex [(papd)Co(O₂)Co(papd)](S₂O₆)(NO₃)₂ · 4 H₂O I crystallizes in the triclinic space group P1 . Lattice constants are a = 9.405(4), b = 9.270(4), c = 12.218(6)Å, α = 89.58(5), β = 99.08(6), γ = 114.79(5)° for Z = 1. The binuclear cation has a center of symmetry, so the Co? O? O? Co unit is planar. Three chelate rings have a common plane, the ligand configuration is δ.     

Synthese,EPR und Röntgenkristallstrukturanalyse von mer-Trichloro(2,2′-bipyridin)nitridotechnetium(VI), einem neuen Nitridokomplex des Technetium(VI)

Synthesis, EPR and X-Ray Structure of mer-Trichloro(2,2′-bipyridine)nitridotechnetium(VI) — a new Technetium(VI) Nitrido Complex mer-Trichloro(2,2′-bipyridine)nitridotechnetium(VI) has been prepared by the reaction of (NBu₄)[TcNCl₄] with 2,2′-bipyridine in acetonitrile, whereas the same procedure gives in methanol the technetium(V) cation [TcNCl(bipy)₂]⁺. The EPR spectrum of [TcNCl₃(bipy)] suggests a meridional coordination of the three chloro ligands. [TcNCl₃(bipy)] crystallizes monoclinic in the space group P2₁/n; a = 8.572(1), b = 15.462(1), c = 10.110(1) Å, β = 104.21(1)°, Z = 4. The R value converged at 0.034 on the basis of 3 040 reflections. The technetium atom is distorted octahedrally coordinated with the chloro ligands meridionally cis with respect to the nitrido nitrogen. The Tc? N(1) bond length is 1.669(4) Å, and the Tc? N(3) bond (2.371(4) Å) is significantly lengthened due to the structural trans labilizing influence of the “N^3?” ligand.     

Structure and EPR spectra of binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acids and 5-substituted 2-hydroxyacetophenones

Binuclear copper(II) complexes with acyldihydrazones of 1,3- or 1,4 benzenedicarboxylic acid and 5-methyl- or 5-bromo-2-hydroxyacetophenone in which coordination polyhedra are connected by an aromatic bridge have been synthesized and studied. The structure of the copper(II) complex with diacylhydrazone of isophthalic acid and 2-hydroxy-5-methylacetophenone (H₄L) of composition [Cu₂L · 3Py] was studied by X-ray diffraction. The crystals are monoclinic: a = 12.1996(12) Å, b = 17.7295(17) Å, c = 17.9339(17) Å, β = 109.7450(10)°, space group P2₁/n, Z = 4. The complex is of the “dimer of dimers” type and contains two binuclear subunits that bind together into a centrosymmetric dimer owing to the coordination of the copper cation to the phenoxyl oxygen atom of a neighboring binuclear molecule to form the Cu₂O₂ moiety, in which the copper atoms are 3.409 Å apart. The distance between the copper(II) cations in the binuclear subunit is 8.56 atoms (2N + O) of the doubly deprotonated acylhydrazone moiety and the nitrogen atom of the pyridine molecule. One of the copper cation is additionally coordinated to an extra pyridine molecule so that its coordination sphere is completed to a tetragonal pyramid. The second copper atom is involved in additional interaction with the phenoxyl oxygen atom of the neighboring molecule. The EPR spectra of solutions of the binuclear complexes show an isotropic signal of four HFS lines (g _o = 2.065–2.143, a _Cu = 52.1–66.5 × 10^?4 cm^?1) typical of mononuclear copper(II) complexes.     

A New Copper(II) Complex with the N,N′‐Tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) Ligand: [Cu(TAMEN)](ClO4)2·H2O·DMF

The synthesis of the Mannich base N,N′‐tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) ( 1 ), its crystal structure as well as the synthesis and the crystal structure of the copper complex [Cu(TAMEN)](ClO₄)₂·H₂O·DMF ( 2 ) are reported. C₅₀H₅₆N₁₀O₄·2C₂H₅OH (TAMEN·2EtOH) crystallizes with triclinic symmetry, space group , lattice parameters: a = 877.3(1), b = 1078.1(1), c = 1433.3(2) pm, α = 71.93(1), β = 82.16(1), γ = 84.54(1)° and Z = 1. The copper complex [Cu(TAMEN)](ClO₄)₂·H₂O·DMF also crystallizes with triclinic symmetry, space group , lattice parameters: a = 1279.2(2), b = 1485.6(2), c = 1513.6(2) pm, α = 98.04(1), β = 101.24(1), γ = 94.66(1)° and Z = 2. The copper(II) atom is six‐coordinate with an elongated pseudo‐octahedral geometry due to a strong Jahn‐Teller effect.     

Synthesis,crystal structure and magnetic properties of the binuclear copper (II) complex of a new bis (1, 4, 7, 10‐tetraazacyclododecane) ligand

A new binucleating macrocyclic ligand 2,6‐bis (1,4,7,10‐tetraazacyclododecan‐10‐ylmethyl) methoxy‐benzene (L) and its binuclear copper (II) complex, [Cu₂LBr₂] (CIO₄ )₂ · 3H₂O (1), was prepared and the structure was determined by X‐ray crystallography. Complex 1 crystallizes in monoclinic crystal system, P2₁/n space group with a = 0.8206(3), b =2.0892(8), c = 2.3053(7) mn, β = 95.83(2)°, V = 3.932 nm³, Mr=1017.57, Z = 4, D_c =1.692 g/cm³, and R= 0.0489, R_w 0.0552 for 6571 observed reflections with I ≥ 2σ (1). Both of the copper(II) centers are coordinated by four amine nitrogen donors of cyclen subunits and a bromide anion, and each copper(II) ion is in a square‐pyramidal coordination environment. Variable temperature magnetic susceptibility studies indicate that there exists weak intramolecular antiferro‐magnetic coupling ( ?2J = 2.06 cm^?1) between the two copper (II) centers.     

Synthese von Kupfer- und Silberkomplexen mit fünfzähnigen N,S- und sechszähnigen N,O-Chelatliganden – Charakterisierung und Kristallstrukturen von {Cu2[C6H4(SO2)NC(O)]2(C5H5N)4}, {Cu2[C5H3N(CHNC6H4SCH3)2]2}(PF6)2 und {Ag[C5H3N(CHNC6H4SCH3)2]}PO2F2

Synthesis of Copper and Silver Complexes with Pentadentate N,S and Hexadentate N,O Chelate Ligands – Characterization and Crystal Structures of {Cu₂[C₆H₄(SO₂)NC(O)]₂(C₅H₅N)₄}, {Cu₂[C₅H₃N(CHNC₆H₄SCH₃)₂]₂}(PF₆)₂, and {Ag[C₅H₃N(CHNC₆H₄SCH₃)₂]}PO₂F₂ In the course of the reaction of copper(II)-acetate monohydrate with 2,2′-bisbenzo[d][1,3]thiazolidyl in methanol the organic component is transformed to N,N′-bis-(2-thiophenyl)ethanediimine and subsequently oxidized to the N,N′-bis-(2-benzenesulfonyl)ethanediaciddiamide H₄BBSED, which coordinates in its deprotonated form two Cu²⁺ ions. Crystallisation from pyridine/n-hexane yields [Cu₂(BBSED)(py)₄] · MeOH. It forms triclinic crystals with the space group P1 and a = 995.5(2) pm, b = 1076.1(3) pm, c = 1120.7(2) pm, α = 104.17(1)°, β = 105.28(1)°, γ = 113.10(1)° and Z = 1. In the centrosymmetrical dinuclear complex the copper ions are coordinated in a square-pyramidal arrangement by three nitrogen and two oxygen atoms. The Jahn-Teller effect causes an elongation of the axial bond by approximately 30 pm. The reactions of the pentadentate ligand 2,6-Bis-[(2- methylthiophenyl)-2-azaethenyl]pyridine BMTEP with salts of copper(I), copper(II) and silver(I) yield the complexes [CU₂(BMTEP)₂](PF₆)₂, [Cu(BMTEP)]X₂ (X = BF, C1O) and [Ag(BMTEP)]X (X = PO₂F, ClO). [Cu₂(BMTEP)₂](PF₆)₂ crystallizes from acetone/diisopropyl- ether in form of monoclinic crystals with the space group C2/c, and a = 1833.2(3) pm, b = 2267.30(14) pm, c = 1323.5(2) pm, β= 118.286(5)°, and 2 = 4. In the dinuclear complex cation with the symmetry C₂ the copper ions are tetrahedrally coordinated by two bridging BMTEP ligands. The Cu? Cu distance of 278.3pm can be interpreted with weak Cu? Cu interactions which also manifest itself in a temperature independent paramagnetism of 0.45 B.M. The monomeric silver complex [Ag(BMTEP)]PO₂F₂ crystallizes from acetone/thf in the triclinic space group P1 with a = 768.7(3) pm, b = 1074.0(5) pm, c = 1356.8(5) pm, α = 99.52(2)°, β = 96.83(2)°, γ = 99.83(2)° and Z = 2. The central silver ion is coordinated by one sulfur and three nitrogen atoms of the ligand in a planar, semicircular arrangement. The bond lengths Ag? N = 240.4–261.7 and Ag? S = 257.2 pm are significantly elongated in comparison with single bonds.     

Hydrothermal Synthesis of Two Mixed‐Valence Copper Complexes with Mixed Ligands

Hydrothermal reactions of copper salts with fumaric acid, 1, 10‐phenanthroline or 2, 2‐bipyridine in basic aqueous solution gave rise to two mixed‐valence copper complexes [Cu₄(ophen)₄(fum)] ( 1 ) and [Cu₄(obipy)₄(fum)]·6H₂O ( 2 ) (fum = fumarate dianion, Hophen = 2‐hydroxy‐1, 10‐phenanthroline and Hobpy = 6‐hydroxy‐2, 2′‐bipyridine), which were characterized by single crystal X‐ray analysis. [Cu₄(ophen)₄(fum)] (1) crystallizes in the monoclinic space group P2₁/n, with a = 10.4749(8), b = 13.4210(9), c = 15.1090(10)Å, β = 103.811(3)° Z = 2; [Cu₄(obipy)₄(fum)]·6H₂O ( 2 ) has the triclinic space group P1¯, with a = 10.1302(11), b = 10.4406(12), c = 11.4450(13)Å, α = 84.384(2)°, β = 79.064(2)°, g = 67.734(2)° and Z = 1. The fumaric acid ligand acts as a multi‐dentate bridging ligand in both compounds, 1 and 2 , to link copper atoms into dumbbell structure. During the reactions, 1, 10‐phenanthroline and 2, 2′‐bipyridine ligands are all hydroxylated into ophen and obipy, which provide useful structural evidence for the study on the Gillard mechanism.     

[Cu4(NPMe3)3(O2C?CH3)5] – ein tetramerer Phosphaniminato-Komplex von Kupfer(II). Synthese,Kristallstruktur, magnetisches Verhalten und EPR-Spektrum

[Cu₄(NPMe₃)₃(O₂C? CH₃)₅] – a Tetrameric Phosphorane Iminato Complex of Copper(II). Synthesis, Crystal Structure, Magnetic Behaviour, and EPR Spectrum The title compound and the corresponding benzoate complex [Cu₄(NPMe₃)₃(O₂C? C₆H₅)₅] have been prepared by reactions of copper(II)acetate and copper(II)benzoate, respectively, with Me₃SiNPMe₃ in dichloromethane. Both complexes are characterized by IR spectroscopy. The acetate complex is additionally characterized by the measurement of the magnetic susceptibility, by its EPR spectrum, and by a crystal structure determination. [Cu₄(NPMe₃)₃(O₂C? CH₃)₅] · CH₂Cl₂: Space group I4₁/a, Z = 16, structure solution with 7 960 independent reflections, R = 0.044. Lattice dimensions at ?70°C: a = b = 3 670.6; c = 1 091.9 pm. The structure consists of four Cu atoms which are arranged at the corners of a distorted tetrahedron with Cu…?Cu distances between 290 and 318 pm. Three of the faces of the tetrahedron are linked by μ₃-N atoms of the phosphorane iminato groups. Three of the acetate ligands form chelates, the other two are monofunctionally coordinated. Three of the copper atoms have a planar surrounding, the forth Cu atom has a (4 + 1) coordination.     

Binuclear Copper(II) Complexes with Robsori-Type Ligands. Synthesis,characterization, crystal structure,and magnetic properties

Three binuclear copper(II) complexes, [Cu₂(μ-L)(μ-N₃)](ClO₄)2′ 1-5 EtOH (1), [Cu₂(μ-L)(μ-MeO)(ClO₄)]-ClO₄ - EtOH ( 2 ) and [Cu₂(μ-L)(μ-C₃H₃N₂)](ClO₄)₂ · 2H₂O, ( 3 ) where L is the pentadentale bridging ligand derived from 5-(tert-butyl)-2-hydroxybenzene-1, 3-dicarbaldehyde bis(benzoylhydrazone) ( HL ) were synthesized and characterized. The crystal-structure determination of complex 2 provided the following crystal data: monoclinic, space group P2₁}/a, a = 11.412(2), b = 24.509(4), c = 14.833(4) Å, β = 104.41(2)°, K = 4018(3) ų, Z = 4. The structure shows that the Cu^II ions are bridged by the endogenous phenolato O-atom and by an exogenous bridge CH₃O^?. The analysis of variable-temperature magnetic susceptibility data (4-300 K.) indicates that there is an antiferromagnetic interaction between the Cu^II ions in these complexes with an exchange parameter (2J) of ?119.1 cm^?1 for complex 1 and ?361.8 cm^?1 for complex 3 . The effect of some exogenous bridging ligands on magnetic coupling for this type of complex is suggested.     

Synthesis,Crystal Structure,and Magnetic Properties of (2,2′‐dipyridylamine)(X−) Copper(II) Complexes (X−: Cyanate,Dicyanamide, Acetate,Thiocyanato)

The synthesis, structure, and magnetic properties of four 2,2′‐dipyridylamine ligand (abbreviated as Hdpa) containing copper(II) complexes. There is one binuclear compound, which is [Cu₂(μ_1,1‐NCO)₂(NCO)₂(Hdpa)₂] ( 1 ), and three mononuclear compounds, which are [Cu{N(CN)₂}₂(Hdpa)₂] ( 2 ), [Cu(CH₃CO₂)(Hdpa)₂·N(CN)₂] ( 3 ), and [Cu(NCS)(Acac)] ( 4 ). Compounds 1 and 4 crystallize in the monoclinic system, space group P2(1)/c and Z = 4, with a = 8.2465(6) Å, b = 9.3059(7) Å, c = 16.0817(12) Å, β = 91.090(1)°, and V = 1233.90(16) ų for 1 and a = 7.6766(6) Å, b = 21.888(3) Å, c = 10.4678(12) Å, β = 90.301(2)°, and V= 1758.8(4) ų for 4 . Compounds 2 and 3 crystallize in the triclinic system, space group P‐1 and Z = 1, with a = 8.1140(3) Å, b = 8.2470(3) Å, c = 9.3120(4) Å, β = 102.2370(10)°, and V = 592.63(4) ų for 2 and a = 7.4780(2) Å, b = 12.5700(3) Å, c = 13.0450(3) Å, β = 96.351(2)°, and V = 1211.17(5) ų for 3 . Complex ( 1 ), the magnetic data was fitted by the Bleaney‐Bowers equation (1). A very good fit was derived with J = 23.96, Θ = ?1.5 (g = 1.97). Complex ( 1 ) shows the ferromagnetism. Complexes ( 2 ), ( 3 ) and ( 4 ) of have the it is the typical paramagnetic behavior of unpaired electrons. Under a low temperature around 25 K, complexes ( 2 ) and ( 3 ) show weak ferromagnetic behavior. They are the cause of hydrogen bonds.     

Salze von Halogenophosphorsäuren. XIV. Darstellung und Kristallstruktur von Kalium-dikupferhydroxid-bis(monofluorophosphat)-Monohydrat Cu2K(OH)(PO3F)2 · H2O

Salts of Halogenophosphoric Acids. XIV. Preparation and Crystal Structure of Dicopper-potassium-hydroxide-bis(monofluorophosphate) Monohydrate Cu₂K(OH)(PO₃F)₂ · H₂O By the reaction of potassium monofluorophosphate and copper(II) salts in aqueous medium a crystalline, insoluble basic copper potassium monofluorophosphate Cu₂K(OH)(PO₃F)₂ · H₂O 1 is formed. The thermal decomposition of 1 has been studied. 1 crystallizes in the monoclinic space group B2/m with a = 9.094 Å, b = 7.755 Å, c = 6.333 Å, α = β = 90°; γ = 117.55°, and Z = 2.     

Kristallstrukturen der Terpyridin-Komplexe [Cd(terpy)Cl2], [Cu(terpy)(CN)Cl] und [Cu(terpy)][Cu(CN)3] · H2O

Crystal Structures of the Terpyridine Complexes [Cd(terpy)Cl₂], [Cu(terpy)(CN)Cl], and [Cu(terpy)][Cu(CN)₃] · H₂O By reaction of cadmium chloride with 2,2′ : 6′,2″-terpyridine (“terpy”) in water/acetone crystals of [Cd(terpy)Cl₂] ( 1) were formed. The compound crystallizes monoclinic, space group P2₁/c, a = 1111.70(10), b = 823.10(7), c = 1643.00(14) pm, β = 93.913(1)°, Z = 4. Starting from mixtures of different molar ratios of copper(II) chloride, terpyridine, and KCN in water/methanole, two complexes of different composition were obtained. At the molar ratio of 1 : 1 : 2 a copper(II) coordination compound with both halide and pseudohalide ligands, [Cu(terpy)(CN)Cl] ( 2 ), was formed which also crystallizes monoclinic, P2₁/c, a = 1065.6(3), b = 824.6(2), c = 1644.5(7) pm, β = 98.214(3)°, Z = 4. At a molar ratio of 1 : 1 : 10 a partial reduction of copper(II) occured with formation of a mixed valency compound [Cu(terpy)][Cu(CN)₃] · H₂O ( 3 ) which crystallizes in the hexagonal space group P6₅22, with a = b = 800.29(1), c = 4771.05(7) pm, Z = 6. Compounds 1 and 2 are structurally similar, the coordination of the metal atoms is square pyramidal. Networks are formed by hydrogen bridges. In 3 the copper(II) ions show a distorted square planar coordination by the three N atoms of the terpy ligand and one N atom of a bridging CN^– group, the copper(I) atoms, however, show trigonal planar coordination by three CN^– ligands to which the water molecules are bonded by hydrogen bridges. Thus helical chains are formed which stretch in the direction of the screw axes. The EPR spectrum of 3 was measured.     

Binuclear copper(II) complexes with acyldihydrazones of <Emphasis Type="Italic">N</Emphasis>-benzenesulfonyl-<Emphasis Type="Italic">L</Emphasis>-aspartic acid

The structure and the EPR spectra of copper(II) coordination compounds with acyldihydrazones of N-benzenesulfonyl-L-aspartic acid and salicylaldehyde (2-hydroxyacetophenone) were described. The compounds were studied by chemical and thermal analyses, IR spectroscopy, and EPR. The molecular and crystal structures of copper(II) complexes with N-benzenesulfonyl-L-aspartic acid bis(salicylidene)hydrazone (H₄L¹) [Cu₂L¹ · 2Py] · 1.5 H₂O was determined by X-ray diffraction. The crystals are triclinic: a = 10.4714(4) Å, b = 12.9702(5) Å, c = 14.6187(9) Å, α = 104.763(2)°, β = 93.082(2)°, γ = 111.4240(10)°, space group P \(\bar 1\), Z = 2. The binuclear complexes containing copper cations whose coordination polyhedra are connected by an aliphatic spacer (Cu...Cu, 8.669 Å) are additionally linked by phenoxy bridges (Cu...Cu, 3.398 Å). The EPR spectra of these compounds in solutions exhibit an isotropic signal of seven HFS lines due to two equivalent copper ions with the spin Hamiltonian parameters g = 2.115?2.120, a _Cu = (35.5?38.0) × 10^?4 cm^?1, which is indicative of weak exchange interactions between the paramagnetic sites.     

Binuclear copper(II) complexes with acyldihydrazones of 1,4-cyclohexanedicarboxylic acid

The binuclear copper(II) complexes with acyldihydrazones formed by 1,4-cyclohexanedicarboxylic acid and salicylaldehyde or 2-hydroxyacetophenone were synthesized and studied. The structure of the complex with 1,4-cyclohexanedicarboxylic acid bis(salicylidene)hydrazone (H₄L¹) [Cu₂L¹(Py)₂] was studied by X-ray diffraction. The crystals are triclinic: a = 8.1852(4) Å, b = 8.5157(5) Å, c = 11.6553(7) Å, α = 80.678(3)°, β = 70.041(4)°, γ = 74.803(3)°. Space group \(P\bar 1\), Z = 1. The number of symmetrically independent reflections with I > 2(σ(I)) is 2245, R = 0.0395; R _w = 0.0917. The complex contains two equivalent copper atoms located at a 10.772 Å distance from each other. The coordination polyhedra have a square geometry and are involved in the intermolecular π/π-stacking. The EPR spectra of solutions of the binuclear complexes show an isotropic signal of seven HFS lines (g = 2.113–2.118, A _Cu ≈ 38 G), indicating interaction between the unpaired electrons and the two equivalent copper nuclei. The possible exchange interaction channels were analyzed.     

Chloroantimonate(III): Die Kristallstruktur des 4,4′-Dipyridylium-pentachloroantimonats, (C10H8N2H2)SbCl5

Chloroantimonates(III): Crystal Structure of 4,4′-Dipyridylium Pentachloroantimonate, (C₁₀H₈N₂H₂)SbCl₅ (C₁₀H₈N₂H₂)SbCl₅ crystallizes in the triclinic space group P1 with a= 843.1(5), b = 958.6(8), c = 1098.0(10) pm, α = 112.45(6), β = 101.95(6), γ = 97.78(6)° and Z = 2. The structure is built up of 4,4 °-dipyridylium cations and pentachloroantimonate anions. The Sb atoms are distorted octahedrally coordinated. Mean distances are Sb? Cl = 242 pm (1×), Sb? Cl = 255 pm (2×), Sb ? Cl = 275 pm (2×) and Sb…?Cl.= 319 pm (1× ). The anions build up dimers.     

Binuclear copper(II) complexes with acyldihydrazones of saturated carboxylic acids and pyruvic acid

Copper(II) binuclear complexes with acyldihydrazones of saturated carboxylic acids and pyruvic acid in which the coordination polyhedra are connected by polymethylene chains of different length (1 to 5 units) were synthesized and studied by chemical and thermogravimetric analysis, IR spectroscopy, and EPR. The structure of binuclear copper(II) complex with succinic acid acyldihydrazone [Cu₂L · 4Py] · 2Py was determined by X-ray diffraction. The crystals are monoclinic: a = 14.3795(6), b = 8.8736(4), c = 15.9147(7) Å, β = 101.062(3)°, space group P2₁/c, Z = 2. The number of independent reflections with I > 2σ(I) = 2804, R = 0.042, R _w = 0.087. The copper atoms are spaced by a chain of seven σ bonds at 8.922 Å. The coordination polyhedron can be described as a tetragonal pyramid highly distorted toward a trigonal bipyramid. The EPR spectra of solutions of complexes based on malonic, succinic, glutaric, and adipinic acids exhibit a poorly resolved signal of seven HFS lines with a constant of (26.3–27.0) × 10^?4 cm^?1, which attests to the presence of weak exchange interactions between paramagnetic centers. An increase in the length of the polymethylene spaur suppresses exchange interactions, and the EPR spectrum of the complex based on pimelic acid acyldihydrazone shows a signal of four HFS lines with a constant of 43.8 × 10^?4 cm^?1 typical of monomeric copper(II) complexes.     

Cobalt-Komplexe mit O2-Brücken: Die Struktur von μ-Peroxo-bis[pentaammincobalt(III)]-tetranitrat-dihydrat

Cobalt Complexes with 0₂ Bridges: Structure of μ-Peroxo-bis[pentaamminecobalt(III)] Tetranitrate Dihydrate An X-ray structure determination of the binuclear complex [(NH₃)₅CoO₂Co(NH₃)₅] (NO₃)₄ · 2 H₂O A has been performed; R = 0.051. A crystallizes in the space group P2₁/n with Z = 2 and with lattice constants a = 11.657(5), b = 11.977(6), c = 8.082(4) Å, and β = 91.58(4)°. The complex cation has crystallographic 1 -symmetry. The Co? O? O? Co unit is planar with an O? O distance of 1.472(6) Å. Two of the three crystallographically independent NO₃ groups show disorder.     

Komplexierung von Gold mit N,N-Dialkyl-N′-benzoythioharnstoffen: Die Kristallstruktur von N,N-Diethyl-N′-benzoylformamidin tetrachloroaurat (III)

Complex Formation of Gold with N,N-Dialkyl-N′-benzoylthioureas: The Crystal Structure of N,N-Diethyl-N′-benzoylformamidin-tetrachloroaurate(III) N,N-Diethyl-N′-benzoylformamidin-tetrachloroaurate(III) AuCl₄C₁₂H₁₇N₂O crystallizes in the monoclinic space group P2₁/c. The cell parameters are a = 7.764(2), b = 14.473(4) and c = 16. 105(9) Å β = 100.75(4) ⁰. The structure was solved with direct methods and refined to a final R-value of 3.38%.