Cobalt(II), nickel(II) and copper(II) complexes of 4-(sulfonylazido)phenylazopyrazolones

Transition metal complexes of Co^II, Ni^II and Cu^II with 4-(4-azidosulfophenylazo)-5-phenyl-3,4-dihydro-2H-pyrazol-3-oneHL¹, 4-(4-azidosulfophenylazo)-5-methyl-2-phenyl-3,4-dihydro-2H-pyrazol-3-one HL² and 4-(3-azidosulfo-6-methoxyphenylazo)-5-methyl-2-phenyl-3,4-dihydro-2H-pyrazol-3-one HL³ were prepared and characterized by elemental analyses, molar conductances and magnetic susceptibilities and by i.r., electronic and e.s.r. spectral measurements as well as thermal (d.t.a and t.g.a.) analysis. The i.r. spectra indicate that HL acts as a bidentate ligand coordinating via the azo and enolic-oxygen linkages. The electronic spectral data and magnetic moments suggest a tetragonally distorted octahedral geometry for the complexes having the formula ML₂·2H₂O, (M = Co^II, Ni^II and Cu^II), square pyramidal geometry for CuL ₂ ³ H₂O and tetrahedral geometry for CoL ₂ ³ . The X-band e.s.r. spectra of the copper(II) complexes reveal anaxial symmetry for both CuL ₂ ² 2H₂O and CuL ₂ ³ H₂O while CuL ₂ ¹ O is isotropic in the solid state at room temperature. The d.t.a. curves show two exothermic peaks for all three complexes CoL ₂ ³ ,NiL ₂ ³ 2H₂O and CuL ₂ ³ H₂O and one endothermic peak for the latter two aqua complexes.     

Copper(I) and copper(II) complexes of diamino-dithioether ligands

Summary Copper(II) salts were reacted with two diamino-dithioether ligands, i.e. 1,3-di(o-aminophenylthio)propane (abbreviated H₂L¹) and 1,2-di(o-aminophenylthio)xylene (abbreviated H₂L²). Mixtures of copper(I) and copper(II) complexes were obtained with Cl^– and ClO ₄ ^– counterions. The major products were the copper(I) complexes, which were obtained pure after recrystallisation from MeCN-MeOH. The ligands lose two protons from the amine functions to form copper(I) complexes of general formula [CuL]X, where X = ClO ₄ ^– or Cl^–. The complexes were oxidised to [CuL]X₂ with H₂O₂ in DMF. Cu(NO₃)₂ on the other hand gave [CuH₂LNO₃]NO₃.     

Direct synthesis,spectral and magnetic properties of trans-aniono(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7-acetato) copper(II) complexes

7-Carboxymethyl-7,16-diaza-18-crown-6 acid hydrates (LH·H₂O) and their copper(II) complexes [CuLX], (X = Cl, Br, NO₃, ClO₄ and CH₃CO₂) were obtained. The earlier X-ray investigation of the [CuLCl] complex, as well as the IR and UV-vis spectral evidence for the complexes revealed the inner chelate structure with the six-coordinated copper(II) ion embedded inside the macrocyclic ligand (deformed octahedral, 4+2, N,N, CO₂⁻,X⁻,O,O-coordination sphere) and the trans arrangement of the CO₂ and X ligands. The spectral data, the conductivity measurements and the chemical properties show the existence of the macrocyclic inclusion cation [CuL]⁺ and the formulation of the complexes as the [(CuL)⁺X⁻] inner salts. The magnetic moments of the complexes amount to 1.76–1.83 BM at room temperature and 1.3–0.92 BM at 4.2 K. These results revealed the monomeric form of the complexes with the occurrence of the intermolecular (through space) magnetic super-exchange interactions of copper(II) paramagnetic centres.     

Cobalt(II), Nickel(II), and Copper(II) Complexes with Diphenylthiocarbazide

New [ML(H₂O)₂] complexes (M = Co²⁺, Ni²⁺, or Cu²⁺; H₂L = diphenylthiocarbazide) were synthesized and studied using IR and diffuse reflection electronic spectroscopy, magnetic chemistry, conductometry, and DTA. The metals were shown to coordinate L^2–through nitrogen and sulfur atoms. The complex [CuL(H₂O)₂] is a dimer.     

Nickel(II) and copper(II) complexes with amidrazone-based ligands: Structure and catalytic activity

Nickel(II) and copper(II) complexes MeL, where H₂LL = [9-(2′-hydroxyphenyl)-6-methyl-3-acetyl-5,7,8-triazanona-3,6,8-trien-2-one], have been synthesized by template reaction of salicylaldehyde acetamidrazone with corresponding Me(acac)₂ and Hacac in the presence of the orthoformic ester at 110°C. The crystal structure of CuL has been determined by X-ray diffraction. The square-planar mode of coordination is realized in CuL. Comparison of geometrical parameters of CuL with those of the corresponding derivative based on S--allylisothiosemicarbazide showed that substitution of the -SR group by methyl in the quadridentate ligand does not affect the mode of binding nor the main interatomic distances and angles in the ligand. The data from magnetic measurements, ¹HH NMR and EI mass spectra indicate that NiL has a similarly structured coordination polyhedron. Epoxidation of norbornene can be performed efficiently with molecular oxygen (1 atm) in THF (or THF-EtOAc) in the presence of CuL at 70°C. The corresponding copper(II) derivatives based on S--substituted isothiosemicarbazides are much less active as catalysts.     

Cu(II) and Cu(I) complexes with 2-(3,5-diphenyl-1H-pyrazole-1-yl)-4,6-diphenylpyrimidine: Synthesis and structure. Catalytic activity of Cu(II) compounds in reaction of ethylene polymerization

The Cu(II) and Cu(I) complexes with 2-(3,5-diphenyl-1H-pyrazole-1-yl)-4,6-diphenylpyrimidine (L) of the composition CuLX₂ (X = Cl, Br) and CuL(MeCN)Br are synthesized. According to X-ray diffraction data, the complexes have molecular structures. The molecules L are coordinated to the copper atom in bidentate-cyclic mode, i.e., through the N² atom of pyrazole and N¹ atom of pyrimidine rings. The coordination polyhedron of the Cu²⁺ ion in CuLX₂ compounds is completed to a distorted tetrahedron with halide ions, that of the Cu⁺ ion in CuL(MeCN)Br compounds, with the bromide ion and the nitrogen atom of acetonitrile molecule. The CuLX₂ complexes (X = Cl, Br) in combination with cocatalysts (methylaluminoxane and triisobutylaluminium) exhibit catalytic activity in ethylene polymerization.     

Copper(II) and nickel(II) complexes of mono-oxocyclam(5-oxo-1,4,8,11-tetraazacyclotetradecane). Synthetic and potentiometric studies

Summary The macrocyclic mono-oxotetraamine, 5-oxo-1,4,8,11-tetraazacyclotetradecane (mono-oxocyclam=LH) has been prepared by reaction of methyl acrylate with 2,3,2-tetra(1,9-diamino-3,7-diazanonane). The protonation constants of the ligand are log K₁=9.40, log K₂=6.65 and log K₃=2.87 at 25 °C (I=0.1 mol dm^–3 NaClO₄). Detailed potentiometric studies of the interaction of the base with copper(II) and nickel(II) have been carried out. In the pH range 2.5–7.0 two complexes, [CuLH]²⁺ and [CuL]⁺, form; the deprotonated complex being 100% abundant at pH 7. For nickel(II), only [NiL]⁺ forms (log _11–1 = 3.90), the yellow low spin nickel complex reaching its maximum concentration above pH 6. The [CuL][ClO₄] · H₂O and [NiL][ClO₄] 0.5 H₂O complexes have been characterised in the solid state. The nickel(II) complex is square planar with a d-d band at 22625 cm^–1.     

Bidentate bonding mode of tetrahydroborate and nitrite towards copper(II) in open-faced macrocyclic complexes

Novel seven-coordinate complexes formulated as [CuL(BH₄)₂], [CuL(BH₄)(NO₂)] and [CuL(NO₂)₂] (L = 1,4,7-triazacyclononane) have been prepared and structurally characterized by elemental analyses, spectroscopic data (u.v., i.r. and e.p.r.), magnetic susceptibility and conductivity measurements. The results reveal that the complexes are non-electrolytic. The coordination geometry around the copper(II) ion is a seven coordinated square pyramidal structure with three nitrogen atoms of the 1,4,7-triazacyclononane and either four hydrogen atoms of two bidentate tetrahydroborate groups or two hydrogen atoms of the bidentate tetrahydroborate group and two oxygen atoms of the bidentate nitrite group or four oxygen atoms of two bidentate nitrito groups. A cyclic voltammetric study on the complexes indicates an irreversible redox couple (Cu^II/Cu^I) in DMF, giving a voltage of ca. −0.37 V versus s.c.e.     

Copper(II), nickel(II) and zinc(II) complexes ofN,N′, N″, N‴-tetra(2-cyanoethyl)-1,4,8, 12-tetra-azacyclopentadecane

Summary Reaction of 1,4,8, 12-tetra-azacyclopentadecance ([15])-aneN₄) with an excess of acrylonitrile gives theN-tetracyanoethylated ligand (L). Several new complexes of this ligand with nickel(II), copper(II) and zinc(II) have been prepared and characterised. The complexes can be formulated [NiL]_n(ClO₄)_2n, [ML](ClO₄)₂ (M=Cu^II and Zn^II), [NiL(NCS)₂], [NiLCl₂], [CuL](NO₃)₂ and [NiL]_n(NO₃)_2n·2H₂O. Spectral, magnetic and conductivity data are reported and possible structures are considered.     

Reactions of Cu(II) and Co(II) acetates, acetylacetonates, and valinates with α,α-Dipyrrolylemethen

The reactions of Co(II) and Cu(II) acetates, valinates, and acetylacetonates with 3,3′,5,5′-tetramethyl-4,4′-dibutyldipyrrolylmethen (HL) in DMF at 298.15 K are studied by spectrophotometric method. The compositions and thermodynamic constants of formation of the Cu(II) and Co(II) complexes are determined using the methods of molar ratios and continuous changes. With an excess in Cu(II) acetate or acetylacetonate, the formation of mixed-ligand complexes CuL(OAc) and CuL(Acac), respectively, was observed, whereas CuL₂ complex was detected in the case of HL excess. At either ratio of the reagent concentrations, reactions of Co(II) acetate and acetylacetonate with HL always afforded CoL₂ complex, while in the case of Cu(II) and Co(II) valinates, only one amino acid ligand was replaced to give ML(Val) complexes (HVal is valine). The chelating capability of the ligand HL toward the Cu²⁺ ion was found to be higher than that toward the Co²⁺ ion.     

Volatile Heteroligand Complexes of Copper(II): New Precursors for Chemical Vapor Deposition of Copper Films

Two heteroligand ketoiminate–diketonate complexes of copper(II), CuL(hfa) (1), L = pentane-2-imino-4-onato, CH₃COCHCNHCH ₃ ^– , and CuL′(hfa) (2), L′ = 2,2,6,6-tetramethyl-3-iminoheptane-5-onato, C(CH₃)₃COCHCNHC(CH)^–, were studied as precursors for chemical vapor deposition of copper films. The flow method was employed to measure the temperature dependences of a saturated vapor pressure of these compounds, the thermodynamic parameters of evaporation–sublimation were calculated, and the volatilities of these compounds and thermal behaviors in the condensed and gaseous phases were compared. The copper films were compared, and it was shown that comparatively high growth rates are reached when (2) is used to obtain copper films in hydrogen.     

Copper(II) complexes based on 2-thenoyltrifluoroacetone aroyl hydrazones: Synthesis,spectroscopy, and X-ray diffraction analysis

Copper(II) complexes CuL ? NH₃ are synthesized by the interaction of ethanol solutions of parasubstituted 2-thenoyltrifluoroacetylmethane aroyl hydrazones (H₂L¹–H₂L⁴) and an aqueous-ammonia solution of copper(II) acetate in an equimolar ratio. The copper(II) complexes are studied by elemental analysis, IR spectroscopy, and EPR spectroscopy. Single crystals of CuL³ ? NH₃ are grown from 1-(2-thenoyl)- 3,3,3-trifluoroacetone para-methylbenzoyl hydrazone and studied using X-ray diffraction analysis (CIF file CCDC 1045841).     

Synthesis, spectral characterization, and structural investigation of mononuclear salen-type Cu(II) and Zn(II) complexes of a potentially octadentate N2O6 Schiff base ligand derived from binaphthol

A new potentially octadentate N₂O₆ Schiff base ligand, H₂L derived from the condensation of 2,2′-(1,1′-binaphthyl-2,2′-diylbis(oxy))dianiline and o-vanillin, along with its copper(II) and zinc(II) complexes, is synthesized and has been characterized by elemental analyses, IR, UV–vis, ¹H and ¹³C NMR spectra, as well as conductivity measurements. H₂L forms mononuclear complexes of 1:1 (metal:ligand) stoichiometry with Cu(II) and Zn(II), and conductivity data confirm the non-electrolyte nature of these complexes. The [ZnL] and [CuL] complexes display very different solid-state structures, as determined by X-ray crystallography. While the [ZnL] complex has a distorted octahedral geometry about the metal, the [CuL] complex displays a distorted square planar geometry about the copper, with long Cu–O(ether) distances of 2.667 Å.     

Copper(II) complexes with derivatives of salen and tetrahydrosalen: a spectroscopic, electrochemical and structural study

Salen type complexes, CuL, the corresponding tetrahydrosalen type complexes, Cu[H₄]L, and N,N′-dimethylated tetrahydrosalen type complexes, Cu[H₂Me₂]L, were investigated using cyclic voltammetry, and electronic and ESR spectroscopy. In addition, the analogous copper(II) complexes with a derivative of the tetradentate ligand ‘salphen’ [salphen=H₂salphen=N,N′-disalicylidene-1,2-diaminobenzene] were studied. Solutions of CuL, Cu[H₄]L and Cu[H₂Me₂]L are air-stable at ambient temperature, except for the complex Cu(^tBu, Me)[H₄]salphen [H₂(^tBu, Me)[H₄]salphen=N,N′-bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)-1,2-diaminobenzene]. Cu(^tBu, Me)[H₄]salphen interacts with dioxygen and the ligand is oxidatively dehydrogenated (–CH₂–NH–→–C=N–) to form Cu(^tBu, Me)[H₂]salphen and finally, in the presence of base, Cu(^tBu, Me)salphen. X-ray structure analysis of Cu(^tBu, Me)[H₂Me₂]salen confirms a slightly tetrahedrally distorted planar geometry of the CuN₂O₂ coordination core. The complexes were subjected to spectrophotometric titration with pyridine, to determine the equilibrium constants for adduct formation. It was found that the metal center in the complexes studied is only of weak Lewis acidity. In dichlormethane, the oxidation Cu(II)/Cu(III) is quasireversible for the CuL type complexes, but irreversible for the Cu[H₄]L and Cu[H₂Me₂]L type. A poorly defined wave was observed for the irreversible reduction Cu(II)/Cu(I) at potentials less than −1.0 V. The ESR spectra of CuL at both 77 K and room temperature reveal that very well resolved lines can be attributed to the interaction of an unpaired electron spin with the copper nuclear spin, ¹⁴N donor nuclei and to a distant interaction with two equivalent protons [A^Cu(iso)≈253 MHz, A^N(iso)≈43 MHz, A^N(iso)≈20 MHz]. These protons are attached to the carbon atoms adjacent to the ¹⁴N nuclei. In contrast to CuL, the number of lines in the spectra of the complexes Cu[H₄]L and Cu[H₂Me₂]L is greatly reduced. At room temperature, only a quintet with a considerably smaller nitrogen shf splitting constant [A^N(iso)≈27 MHz] is observed. Both factors, planarity and conjugation, are thus essential for the observation of distant hydrogen shf splitting in CuL. Due to the C=N bond hydrogenation, the coordination polyhedra of the complexes Cu[H₄]L and Cu[H₂Me₂]L is more flexible and more sensitive to ligand modification than that of CuL. The electron-withdrawing effect of the phenyl ring of the phenylenediamine bridge is reflected in a reduction of the copper hyperfine coupling constants in Cu(^tBu, Me)[H₄]salphen and Cu(^tBu, Me)[H₂Me₂]salphen complexes [A^Cu(iso)≈215 MHz].     

Syntheses,characterization and crystal structures of mixed-ligand Cu(II), Ni(II) and Mn(II) complexes of N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-salicylidene hydrazide containing ethanol or pyridine as a co-ligand

Five new mixed-ligand complexes [CuL(EtOH)] (1), [NiL(EtOH)₃] (2), [Mn₂L₂(μ₂-EtOH)₂(EtOH)₂] (3), [CuL(Py)] · MeOH (4) and [NiL(Py)₃] (5) (L²⁻ = N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-salicylidene hydrazide anion, Py = pyridine) have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and single crystal X-ray diffraction. The crystallographic structural analyses of these complexes reveal that the ligand (H₂L) itself undergoes isomerization from the keto form to the enol form in the reaction, then loses two protons and acts as a double negatively charged tridentate chelating agent coordinated to the metal ion in the solution. The final results show that when a co-ligand was present in the synthetic reaction, other coordination sites around the metal ions Cu²⁺ and Ni²⁺ were completed either by the ethanol or pyridine molecules under the common solvent reaction or solvothermal syntheses conditions, respectively. In the case of the Mn²⁺ ion, it was still coordinated with the solvent molecules regardless of whether it was synthesized under the common solvent reaction or solvothermal syntheses with pyridine. The reason for this difference might be attributed to the fact that the coordination modes and bonding effect of the co-ligand with the metal ions are different, the final complexes tend to form the most stable compound.     

Copper(II), nickel(II) and cobalt(II) complexes of 5,5-dimethylcyclohexane-1,2,3-trione-2-arylhydrazones

Summary Copper(II), nickel(II) and cobalt(II) perchlorate complexes of 5,5-dimethylcyclohexane-1,2,3-trione-2-(p-nitrophenyl-hydrazone) (HL¹), 5,5-dimethyl-cyclohexane-1,2,3-trione-2-(p-chlorophenylhydrazone) (HL²), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-chlorophenylhydrazone) (HL⁴), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-methylphenyl-hydrazone) (HL⁵) and 5,5-dimethylcyclohexane-1,2,3-trione-2-(m-methylphenylhydrazone) (HL⁶) have been prepared, and characterized using analytical, spectral and magnetic measurements. The data reveal that the reaction of Cu(ClO₄)₂ (1 mol) in EtOH, with all ligands, produces complexes of the type CuL(ClO₄)(H₂O).nH₂O. Nickel(II) and cobalt(II) perchlorates react only with HL¹ and HL² to produce the complexes ML(ClO₄)(H₂O)₃ (where M = Ni^II, L = L^– and L², M = Co^II, L = L¹) and Co(HL₂)₂-(ClO₄)₂.2H₂O. The spectral data show that the ligands behave as monobasic bidentate in their azo forms, except HL² which reacts with cobalt(II) as a neutral bidentate ligand in its hydrazone form.     

Study of some trinuclear copper(II) complexes involving catechol aldehyde and heteroaromatic nitrogen bases

Trinuclear copper(II) complexes of types [A¹CuL(CuCl₂)L · CuA¹] and [A¹Cu · L{Cu(A-A)}L · Cu · A¹](ClO₄)₂ have been studied, where L = 3,4-dihydroxybenzaldehyde and A-A = 2,2′-bipyridyl (A¹), 1,10-phenanthroline (A²) or 2-(2′-pyriyl)-benzimidazole (A³).     

Catalytic activity of some new copper(II) azo-complexes

Copper(II) complexes [Cu(L)₂]?·?nH₂O, where L is 3-(p-X-)-4-hydroxy-l,2-naphthoquinone (for L1, X?=?H; L2, X?=?CH₃; L3, X?=?Cl; L4, X?=?Br; and L5, X?=?NO₂), have been synthesized and characterized by analytical, electrochemical, spectroscopic (IR, UV-Vis, ESR, and ¹H NMR), and magnetic methods. From the data obtained, square-planar geometry has been assigned for all the complexes. [CuL1]?·?H₂O exhibits catalytic activity for oxidation of benzyl alcohol, piperonyl alcohol, and cinnamyl alcohol into their respective aldehydes in the presence of H₂O₂ as co-oxidant and in CH₃CN and H₂O as solvents at room temperature.     

Synthesis,crystal structure and infrared spectra of Cu(II) and Co(II) complexes with 4,4′‐dichloro‐2,2′‐[ethylene dioxybis(nitrilomethylidyne)]diphenol

Novel 4,4′‐dichloro‐2,2′‐[ethylenedioxybis(nitrilomethylidyne)]diphenol (H₂L) and its complexes [CuL] and {[CoL(THF)]₂(OAc)₂Co} have been synthesized and characterized by elemental analyses, IR, ¹H‐NMR and X‐ray crystallography. [CuL] forms a mononuclear structure which may be stabilized by the intermolecular contacts between copper atom (Cu) and oxygen atom (O3) to form a head‐to‐tail dimer. In {[CoL(THF)]₂(OAc)₂Co}, two acetates coordinate to three cobalt ions through Co? O? C? O? Co bridges and four µ‐phenoxo oxygen atoms from two [CoL(THF)] units also coordinate to cobalt ions. Copyright © 2008 John Wiley & Sons, Ltd.     

Syntheses and crystal structures of two Schiff-base copper(II) complexes with urease inhibition

Two new copper(II) complexes, [CuL1(N₃)] (1) and [CuL2(NCS)] (2) (HL1 = 4-chloro-2-[(2-piperidin-1-ylethylimino)methyl]phenol, HL2 = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol), were prepared and structurally characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Complex 1 is an azide coordinated mononuclear complex, while complex 2 is a terminal thiocyanate coordinated mononuclear complex. The coppers in both complexes are four-coordinate, square-planar. Both complexes show potent urease inhibitory properties.