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.     

Crystal Structures,Magnetic Properties and Catecholase‐Like Activities of μ‐Alkoxo‐μ‐Carboxylato Double Bridged Dinuclear and Tetranuclear Copper(II) Complexes

One μ‐alkoxo‐μ‐carboxylato bridged dinuclear copper(II) complex, [Cu₂(L¹)(μ‐C₆H₅CO₂)] ( 1 )(H₃L¹ = 1,3‐bis(salicylideneamino)‐2‐propanol)), and two μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear copper(II) complexes, [Cu₄(L¹)₂(μ‐C₈H₁₀O₄)(DMF)₂]·H₂O ( 2 ) and [Cu₄(L²)₂(μ‐C₅H₆O₄]·2H₂O·2CH₃CN ( 3 ) (H₃L² = 1,3‐bis(5‐bromo‐salicylideneamino)‐2‐propanol)) have been prepared and characterized. The single crystal X‐ray analysis shows that the structure of complex 1 is dimeric with two adjacent copper(II) atoms bridged by μ‐alkoxo‐μ‐carboxylato ligands where the Cu···Cu distances and Cu‐O(alkoxo)‐Cu angles are 3.5 11 Å and 132.8°, respectively. Complexes 2 and 3 consist of a μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear Cu(II) complex with mean Cu‐Cu distances and Cu‐O‐Cu angles of 3.092 Å and 104.2° for 2 and 3.486 Å and 129.9° for 3 , respectively. Magnetic measurements reveal that 1 is strong antiferromagnetically coupled with 2J =‐210 cm^?1 while 2 and 3 exhibit ferromagnetic coupling with 2J = 126 cm^?1 and 82 cm^?1 (averaged), respectively. The 2J values of 1–3 are correlated to dihedral angles and the Cu‐O‐Cu angles. Dependence of the pH at 25 °C on the reaction rate of oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ) catalyzed by 1–3 was studied. Complexes 1–3 exhibit catecholase‐like active at above pH 8 and 25 °C for oxidation of 3,5‐di‐tert‐butylcatechol.     

Synthesis and Structural Characterization of a Binuclear Mixed‐Ligand (Salicylate and N,N‐diethylnicotinamide) Nickel(II) Complex,Its Magnetic Properties. [Ni2(µ‐Sal)4(Dena)2]H2O

The title complex of [Ni₂(µ‐Sal)₄(Dena)₂]H₂O, [( µ‐tetrakissalicylato‐κ‐O,O)(bis‐N,N‐diethylnicotinamide‐κ‐N)(binickel(II))]hydrate, C₄₈H₅₂Ni₂N₄O₁₆, has been synthesized and explained as structural using some elemental analysis, FT‐IR spectra, UV‐Vis reflectance, magnetic measurements, thermal analysis and x‐ray diffraction methods. The analysis results showed that the unit cell of complex includes two molecules Ni^II cation, four molecules salicylates as bridge and two molecules N,N‐diethylnicotinamide ligands, also there is one molecule hydrated aqua. The compound crystallizes in the monoclinic space group P2₁/c with the following unit‐cell parameters: a =13.6776(6) Å, b =10.5238(3) Å, c =21.8165(9), α=90.00°, β=126.546(3)°, γ=90.00º and Z=2. The compound [Ni₂(µ‐Sal)₄(Dena)₂]H₂O is a typical paddle‐wheel complex structure. Two Ni^II ions are bridged by four salicylate ligands (O2, O2ⁱ, O3, O3ⁱ, O5, O5ⁱ, O6 and O6ⁱ) using a µ‐COO^? coordination mode [symmetry code: (i) 1‐x, 1‐y, 1‐z]. Each Ni^II also coordinates to one nitrogen atom (N1 and N1ⁱ) from one N,N‐diethylnicotinamide ligand molecule in the axial position. The complex has strong paramagnetic properties.     

Binuclear Complexes. II. Electron Paramagnetic Resonance Study of Binuclear Copper Complexes with α-Diimine Ligand

A series of biouclear copper (II) complexes containing a-diimine ligand has been synthesized and characterized by electron paramagnetic resonance spectroscopy. The copper complexes of the form [Cu(dien)D](ClO₄)₂ or [Cu2(dien)₂L](CIO₄)₄, where dien is diethylenetriamine, L' is monodentate ligand and L is bridging ligand, were studied. The EPR spectra were recorded in solution and frozen glassy solution. In the frozen solution spectra, the values of G‖ are in the range of 2.10 to 2.20, and the g⊥ are in the range of 2.03 to 2.06. Furthesmore, the values of A‖ are in the range of 170 to 188 gauss, and the A ⊥ are in the range of 17 to 32 gauss. The data indicate that the structure of Cu(II) complexes is axial symmetry in square pyramidal form.     

Synthesis, Structure and Magnetic Properties of a Diphenoxo-bridged Binuclear Copper(II) Complex

ＩｎｔｒｏｄｕｃｔｉｏｎＥｘｃｈａｎｇｅ ｃｏｕｐｌｅｄｐｏｌｙｎｕｃｌｅａｒｃｏｐｐｅｒ(ＩＩ)ｃｏｍｐｌｅｘ ｅｓａｒｅｏｆｓｐｅｃｉａｌｉｎｔｅｒｅｓｔｄｕｅｔｏｔｈｅｉｒｉｎｖｏｌｖｅｍｅｎｔｉｎｂｉｏ ｌｏｇｉｃａｌｐｒｏｃｅｓｓｅｓａｎｄｉｎｉｎｏｒｇａｎｉｃｍａｔｅｒｉａｌｓ .1,2 Ｔｈｅｉｎｔｉ ｍａｔｅｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｔｈｅｓｐｉｎｃｏｕｐｌｉｎｇａｎｄｔｈｅｍｏｌｅｃｕｌａｒｓｔｒｕｃｔｕｒｅｈａｓｆｏｓｔｅｒｅｄｔｈｅｅｍｅｒｇｅｎｃｅｏｆｍｏｌｅｃ ｕｌａｒ…     

Synthesis,Structure and Magnitic Properties of a Diphenoxobridged Binuclear Copper（Ⅲ） Complex

A mixed-ligand copper(Ⅱ） complex[Cu2(phen)2(HL^1)2]-(ClO4)2(1) was synthesized.X-ray analyses reveal that 1 has a bis(μ2-phenoxo)-bridged dicopper(Ⅱ） structure.2D hydrogen-bonded network is formed utilizing the N-H,O-H and C-H groups of the (HL^1) ligands (H2L^1=N-(2-hydroxybenzyl)ethanolamine),the C-H groups of the phenanthrolines and the perchlorate anions.Variable temperature magnetic properties of 1 have shown comparatively weak antiferromagnetic interactions with respect to the bridge angles, which have been ascribed to the unfavorable overlaps of the magnetic orbitals fo the highly distorted copper coordination polyhedra and the pyramidal distortions at the phenoxo oxygen atoms.     

Magnetic Properties and Mössbauer Spectra of Binuclear Copper(II) and Tetranuclear Diiron(III)-porphyrin-dicopper(II) Complexes with Schiff-Base Ligands of 2-lmidazolealdehyde and Acetylpyrazine

The binuclear copper(II) and tetranuclear diiron(III)-porphyrin-dicopper(II) complexes with the Schiff-base ligands of N,N′-bis(2-imidazolaldehyde)ethylenediimine, N,N′-bis(2-imidazolaldehyde)-p-phenyldiimine, N,N-bis(acetylpyrazine)-ethylenediimine and N,N′-bis(acetylpyrazine)-p-phenyldiimine have been prepared and characterized. The magnetic data indicated that the spin ground states and the magneic interaction between Cu(II)-Cu(II) or Fe(III)-Cu(II) are dependent on the nature of the bridging ligands. A weak antiferromagnetic interaction between Fe(III) and Cu(II) is evident from the temperature-dependent magnetic measurements. The Mössbauer spectra of iron(III) -porphyrin sites showed an asymmetric quadrupole doublet consistent with high-spin iron(III) S = 5/2.     

四碘代对苯二甲酸根桥联的双钴(II)配合物的研究

报导了四种新的双核钴（Ⅱ）配合物，即［Co2（4I-TPHA）（L）4］（COl4）（4I-TPHA＝四碘代对苯二甲酸根阴离子，L＝1，10菲咯啉（phen）（1），5-硝基-,10菲咯啉（NO2-phen）（2），2，2′-联吡啶（bpy）（3）和4，4′-二甲基-2，2′-联吡啶（Me2bpy）（4）的合成和表征，配合物的磁性研究表明双核钴（Ⅱ）离子间有弱的反铁磁性自旋交换相互作用。     

Synthesis, Structure and Magnetic Properties of Two New Homotrinuclear Bis(oxamato) Copper(II) Complexes

ＩｎｔｒｏｄｕｃｔｉｏｎＭｏｌｅｃｕｌａｒｍａｇｎｅｔｉｓｍｏｆｐｏｌｙｎｕｃｌｅａｒｃｏｍｐｌｅｘｅｓｉｓｏｆｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒｅｓｔｆｏｒｄｅｓｉｇｎｉｎｇｎｅｗｍａｇｎｅｔｉｃｍａｔｅｒｉａｌｓａｎｄｆｏｒｉｎｖｅｓｔｉｇａｔｉｎｇｔｈｅｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｔｈｅｓｔｒｕｃｔｕｒｅａｎｄｔｈｅｒｏｌｅｏｆｔｈｅｐｏｌｙｍｅｔａｌｌｉｃａｃｔｉｖｅｓｉｔｅｓｉｎｂｉｏｌｏｇｉｃａｌｓｙｓｔｅｍｓ.1 4 Ｊｏｕｒｎａｕｘｅｔａｌ .5ｈａｖｅｒｅｃｅｎｔｌｙｐｒｏｐ…     

配合物[Cu(PTA)(phen)2]·(PTA)·(H2O)4的合成、晶体结构及电化学性质

The title complex has been synthesized by using terephthalic acid (PTA), 1,10-phenanthroline (phen) and copper monohydrate. It crystallizes in monoclinic space group C2/c with a=2.959 0(2) nm, b=1.466 4(10) nm, c=1.764 3(12) nm, β=105.593(11)°, V=7.372(9) nm³, Dc=1.489 g·cm^-3, Z=8, F(000)=3 416, R₁=0.043 6, wR₂= 0.151 9. The crystal structure shows that the copper atom is coordinated with four nitrogen atoms from two phens and one oxygen atom from one terephthalic acid, forming a distorted square-pyramid coordination geometry. The cyclic voltametric behavior of the complex is also reported. CCDC: 277047.     

Synthesis and Characterization of Copper(II) and Zinc(II) Tricyanomethanide (tcm) Complexes with Di(2‐pyridyl)amine (dpyam) as Co‐ligands: [Cu(dpyam)(tcm)2], [Cu(dpyam)(tcm)(OAc)] and Zn(dpyam)2(tcm)2

Three new transition metal tricyanomethanide complexes [Cu(dpyam)(tcm)₂] ( 1 ), [Cu(dpyam)(tcm)(OAc)] ( 2 ) and Zn(dpyam)₂(tcm)₂ ( 3 ) were synthesized and characterized by single crystal X‐ray diffraction analysis. In 1 each copper(II) atom is coordinated to three tcm anions and one dpyam molecule to form a square pyramide geometry. In 2 the coordination geometry around the central metal is also square pyramidal, and each copper atom is surrounded by two tcm anions, one dpyam ligand and one OAc. Both 1 and 2 display a µ_1,5‐tcm bridged infinite chain structure. In 3 each zinc(II) atom is coordinated by two tcm anions and two dpyam molecules to form a distorted octahedral geometry. Different from the former two complexes, 3 shows a mononuclear structure. Magnetic susceptibility measurement in the range 2–300 K indicates that there are weak antiferromagnetic couplings between adjacent copper(II) ions in 1 (J=?0.03 cm^?1) and 2 (J=?0.11 cm^?1) respectively.     

Synthesis,Characterization and Magnetic Studies of μ‐Oxamido Copper (II) ‐ Chromium (III) Heterodinuclear Complexes

Three new μ‐oxamido‐bridged heterodinuclear copper (II)‐chromium (III) complexes formulated [Cu(Me₂oxpn)Cr‐(L)₂](NO₃)₃, where Me₂oxpn denotes N,N'‐bis(3‐amino‐2, 2‐dimethylpropyl)oxamido dianion and L represents 5‐methyl‐1,10‐phenanthroline (Mephen), 4,7‐diphenyl‐1,10‐phenanthroline (Ph₂phen) or 2,2′‐bipyridine (bpy), have been synthesized and characterized by elemental analyses, IR and electronic spectral studies, magnetic moments of room‐temperature and molar conductivity measurements. It is proposed that these complexes have oxamido‐bridged structures consisting of planar copper (II) and octahedral chromium (III) ions. The variable temperature magnetic susceptibilities (4.2–300 K) of complexes [Cu(Me₂oxpn)Cr(Ph₂phen)₂](NO₃)₃ (1) and [Cu(Me₂oxpn)Cr(Mephen)₂] (NO₃)₃ (2) were further measured and studied, demonstrating the ferromagnetic interaction between the adjacent chromium (III) and copper (II) ions through the oxamido‐bridge in both complexes 1 and 2. Based on the spin Hamiltonian, ? = ‐ 2J?₁ · ?₂, the exchange integrals J were evaluated as + 21.5 an^?1 for 1 and + 22.8 cm^?1 for 2.     

Preparation, Crystal Structure and Properties of a Pentametallic 3-Ferrocenyl-2-crotonic acid-Bridged Copper（Ⅱ） Complex

The synthesis and characterization of the copper (II) complex [Cu₂(OOCCH = C(CH₃)Fc)₃(phen)₂]CIO₄ · 2H₂O (1) are reported. The structure of the complex was determined by single‐crystal X‐ray analysis. The compound crystallizes in the monoclinic system, space group Pc, with Z =2, a = 1.2799(4) nm, b =0.9969 (4) nm, c = 2.5228 nm, and β = 91.576 (1) °. The cationic part of 1 indicates a penametallic core in which three 3‐ferrocenyl‐2‐crotonic acid salt (FCA) groups act as (O, O') bridging ligands between two copper (II) ions with a square‐pyramidal environment. Cyclic voltammetric experiments in acetonitrile have been performed mainly to examine the Fe(II) → Fe(III) one‐electron oxidation in FCA and its complex. The variable‐temperature magnetic susceptibility measurements revealed very weak intramolecular anti‐ferromagnetic coupling. Fitting parameters are 2J = ‐0.2 cm^?1, g = 2.114, and θ = 0K.     

Syntheses,Crystal Structures,and Magnetic Properties of Carboxylate-Bridged Copper(II) Complexes with Bis(2-Pyridylmethyl)Amino Acids

Tetradentate Schiff-base carboxylate-containing ligands, bis(2-pyridylmethyl)amino-5-valeric acid (Hpmva) and bis(2-pyridylmethyl)amino-6-caproic acid (Hpmca), react with copper(II) perchlorate to give rise to the carboxylated bridged chain complexes {[Cu(μ-pmva)(H₂O)](ClO₄)}_n (1) and {[Cu(μ-pmca)(H₂O)](ClO₄)}_n (2). These complexes have been characterized by X-ray crystallography, spectroscopic, and variable-temperature magnetic susceptibility measurements. In 1 and 2, each of the copper(II) ions exhibit CuN₃O₂ coordination environments with the three nitrogen atoms of the ligand and one oxygen atom belonging to the carboxylate group of an adjacent molecule occupying the basal position and a water molecule coordinated in the axial position. The electronic spectra of the complexes are significantly affected by the coordination geometry. Magnetic susceptibility measurements indicate that complexes exhibit very weak ferromagnetic interactions.     

双核配合物[Cu2(L-Asp)(phen)3(NO3)](NO3)·4H2O的合成及晶体结构

The new complex [Cu₂(L-Asp)(phen)₃(NO₃)](NO₃)·4H₂O (L-Asp=L-aspartic acid and phen=1,10-phenanthroline) has been synthesized and its crystal structure has been determined. The complex crystallizes in the monoclinic with space group P2₁/c, The cell parameters are: a=1.261 3(2) nm, b=1.500 8(4) nm, c=2.230 7(4) nm, β=99.55(1)°, and V=4.164 1(16) nm³，D_c=1.587 g·cm^-3. The complex contains two six-coordinated copper ions, and these two copper ions are connected together by L-aspartate to give rise to a binuclear structure. Hydrogen bonds and π-π stacking interactions are observed in the complex. CCDC: 249250.     

Synthesis and Characterization of New Macrocyclic Cu（Ⅱ） Complexes from Various Diamines, Copper（Ⅱ） Nitrate and 1,4-Bis（2-formylphenoxy）butane

Six new macrocyclic complexes were synthesized by a template reaction of 1,4-bis（2-formylphenoxy）butane with diamines and Cu（NO3）2·3H2O and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, magnetic susceptibility measurements, molar conductivity measurements and mass spectra. The metal to ligand molar ratios of the Cu（Ⅱ） complexes were found to be 1 ： 1. The Cu（Ⅱ） complexes are 1 ： 2 electrolytes as shown by their molar conductivities （∧m） in DMF at 10^-3 mol·L^-1. Due to the existence of free ions the Cu（Ⅱ） complexes are electrically conductive. Their configurations were proposed to be probably distorted octahedral.     

Synthesis, Crystal Structures and Thermal Decomposition of Two Novel Supramolecular Complexes [Ni(cyclen)(H2O)2] (tpa) and [Cu(cyclen)H2O](tpa)?3H2O (Cyclen = 1,4,7,10? Tetraazacyclododecane, tpa = Dianion of Terephalic Acid)

Two novel supramolecular complexes [Ni(cyclen)(H₂O)₂](tpa)(1) and [Cu(cyclen)H₂O](tpa)⋅3H₂O (2) were synthesized and their structures were characterized with elemental analysis, IR spectrum, TGA and X-ray diffractometer, indicating that the complexes 1 and 2 consist of one-dimensional chain and two-dimensional net-work structures formed by intermolecular hydrogen-bonding interaction, respectively. TGA curves show the similar steps of weightloss for 1 and 2.     

Synthesis and Characterization of Nickel(II) and Copper(II) Complexes with Schiff Base (1R,2R)-(-)-Diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene)

Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082(2), b = 15.447(3), c = 18.784(4) , V = 3505.7(12) 3, Mr = 731.50, Dc = 1.386 g/cm3, μ = 0.606 mm–1, F(000) = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I > 2σ(I). For 2, a = 12.181(2), b = 15.501(3), c = 18.877(4) , V = 3564.3(12) 3, Mr = 736.33, Dc = 1.372 g/cm3, μ = 0.665 mm–1, F(000) = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I > 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π···π interactions.     

Synthesis, Structure and Spectral Characterization of a Discrete Binuclear Copper (II) Complex

1　ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｌｙ,ｂｒｉｄｇｅｄｂｉｎｕｃｌｅａｒｃｏｍｐｌｅｘｅｓｏｆｆｉｒｓｔｒｏｗｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓｈａｖｅｒｅｃｅｉｖｅｄｍｕｃｈａｔｔｅｎｔｉｏｎｏｎａｃｃｏｕｎｔｏｆｔｈｅｉｒｂｉｏｌｏｇｉｃａｌｒｅｌｅｖａｎｃｅａｎｄｃｏｎｄｅｎｓｅｄｐｈａｓｅｍａｇｎｅｔｉｃｐｒｏｐｅｒｔｉｅｓ[1,2].Ｉｎｔｈｅｓｅｒｅｓｅａｒｃｈｅｓ,ｍａｎｙｂｒｉｄｇｅｄｌｉｇａｎｄｓｗｈｉｃｈｐｌａｙｉｍｐｏｒｔａｎｔｒｏｌｅｓｈａｖｅｂｅｅｎｕｓｅｄａｓｕｓｅｆｕｌ…