Spectrochemical Properties of Noncubical Transition Metal Complexes in Solutions. XV. Solution Properties of bis(Salicylideneaniline)Copper(II)

The complex obtained by condensation of salicylideneaniline with copper(II) acetate was studied in a variety of solvents. This deep-brown crystalline compound is soluble in common solvents, such as, chloroform, toluene, dioxane, methanol, ethanol, dimethyl formamide, dimethyl sulfoxide, and acetonitrile—a necessary condition for observing solvatochromism. The complex has been characterized by elemental analysis, molar conductivity, EPR, and ultraviolet (UV) and visible (VIS) spectroscopy. The available X-ray data shows planar coordination geometry for the copper center. Combined multi-technique experiments have been applied to confirm the structure of the complex in solution. The molar conductivities indicate nonelectrolytic properties. EPR measurements preclude the possibility of solvent coordination at the axial positions of the complex. Spectroscopic measurements were used to study the coordination properties of donor atoms and their bonding ability, as well as trichromaticity coordinate calculations. The results obtained show that the interactions of metal with donors depend on donor strength and polarity of solvent.     

Spectrochemical properties and solvatochromism of bis(salicylidene-2-amino-3-methylpyridine)copper(II)

The title complex, denoted as [Cu(Msap)₂], is a deep brown solid soluble in common solvents like chloroform, toluene, benzene, dioxane, acetone, methanol, ethanol, 2-propanol, dimethylformamide, dimethyl sulfoxide, and acetonitrile that is a necessary condition for solvatochromism observation. The complex has been characterized by elemental analysis, molar conductivity, ultraviolet, and visible spectroscopy. The available X-ray data for similar compounds show that copper atom adopts planar coordination geometry. The molar conductivities indicate their non-electrolytic properties. The electronic spectra have been used to study the coordination properties of donor atoms and their bonding abilities, as well as solvatochromism. The results obtained show that the interactions of metal with donors depend on solvent polarity and the color changes are subtle.     

Speciation of copper(II) complexes in an ionic liquid based on choline chloride and in choline chloride/water mixtures

A deep-eutectic solvent with the properties of an ionic liquid is formed when choline chloride is mixed with copper(II) chloride dihydrate in a 1:2 molar ratio. EXAFS and UV-vis-near-IR optical absorption spectroscopy have been used to compare the coordination sphere of the cupric ion in this ionic liquid with that of the cupric ion in solutions of 0.1 M of CuCl(2)·2H(2)O in solvents with varying molar ratios of choline chloride and water. The EXAFS data show that species with three chloride ions and one water molecule coordinated to the cupric ion as well as species with two chloride molecules and two water molecules coordinated to the cupric ion are present in the ionic liquid. On the other hand, a fully hydrated copper(II) ion is formed in an aqueous solution free of choline chloride, and the tetrachlorocuprate(II) complex forms in aqueous choline chloride solutions with more than 50 wt % of choline chloride. In solutions with between 0 and 50 wt % of choline chloride, mixed chloro-aquo complexes occur. Upon standing at room temperature, crystals of CuCl(2)·2H(2)O and of Cu(choline)Cl(3) formed in the ionic liquid. Cu(choline)Cl(3) is the first example of a choline cation coordinating to a transition-metal ion. Crystals of [choline](3)[CuCl(4)][Cl] and of [choline](4)[Cu(4)Cl(10)O] were also synthesized from molecular or ionic liquid solvents, and their crystal structures were determined.     

EPR and electronic spectral properties of aryl-substituted bis(dithiophosphato)copper(II) complexes

The spectral properties of bis(diaryl-dithiophosphato)copper(II) complexes, [Cu(S(2)P(OR)(2))(2)], with R = o-cresyl (complex I) and 2,6-dimethylphenyl (complex II) are studied by EPR- and vis spectroscopy. In solid (powder) state both complexes exhibit dark brown colour and are paramagnetic. Room temperature EPR spectra of the complexes dissolved in non-coordinating (C(6)H(5)CH(3), C(5)H(12), C(6)H(14)), acceptor (CHCl(3), CCl(4)) or donor (DMFA, DMSO) solvents have typical features of the chromophore CuS(4). In non-coordinating and acceptor solvents their isotropic EPR parameters are: g(iso)=2.047+/-0.003, (Cu)A(iso) = 7.2+/-0.1 mT and (P)A = 0.95+/-0.1 mT. An absorption band characterizes the vis spectra in these solvents with a maximum at 427 nm, due to a ligand-to-metal charge-transfer transition. One hour after dissolution the absorbance at 427 nm follows Beer's law with molar absorptivity (epsilon) about 11000, which does not change significantly after 24 h staying at room temperature or after 30 min heating at 50 degrees C. Both DMFA and DMSO exhibit specific solute-solvent interaction with the acceptor centre of copper complex yielding an axial adduct, with increased g-factor and decreased (hf)A compared to the initial complex. An additional EPR signal with unresolved hyperfine structure is also detected in DMSO. EPR and vis intensities of both bis(diaryl-dtp)Cu(II) complexes decrease after dissolution in both solvents. Moreover, they are EPR silent in pyridine and do not show any absorption in the vis spectra.     

Coordination polymers of copper(II) with some dicarboxysiloxane ligands

Several new coordination polymers of copper(II) with different carboxylate ligands containing siloxane units were synthesized by equilibrium polycoordination reactions of copper(II) acetate with the proper dicarboxylic acid (i.e. 1,3‐bis(3‐carboxypropyl)tetramethyldisiloxane, α,ω‐bis(3‐carboxypropyl)oligodimethylsiloxane, and 1,3‐bis(sebacomethyl)tetramethyldisiloxane) in solution (methanol), at room temperature. Some variations in the feed molar ratios were made. The resulting polymers having a polycoordination degree between 5 and 71 are soluble in a wide range of common organic solvents. The formation of polymers was proved by IR and UV–VIS absorption spectroscopy. The thermal behaviour of the coordination polymers was analysed by thermogravimetry in air. The silicon and copper contents and inherent viscosities were also determined. Copyright © 2002 John Wiley & Sons, Ltd.     

利用氧化加成反应合成[Cu(C_6H_5COO)_2(C_5H_5N)_2(H_2O)]

室温下 ,金属铜粉和过氧化苯甲酰进行氧化加成反应合成了铜化合物 [Cu(C6H5COO) 2 (C5H5N) 2 (H2 O) ](1 )。通过元素分析、电导、红外光谱等方法对配合物进行了表征 ,并经X 射线单晶结构分析确定了配合物的结构 ,晶体属单斜晶系 ,空间群Cc ,a =0 .60 78(4) ,b =1 .5879(4) ,c =2 .30 91 (3)nm ,β =97.61 (2 )°,Z =4,V =2 .2 0 91nm3,R =0 .0 30 7,中心铜原子由单齿配位的苯甲酸根的氧原子和吡啶的氮原子及来自水分子的氧原子形成四方锥配位结构。     

Complex formation of 5-hydroxyorotic acid with copper(II) ions in water solutions

Complex formation of 5-hydroxyorotic acid with copper(II) chloride in water solution is studied by electron spectroscopy. The composition of the complex was established spectrophotometrically by molar ratio method and confirmed by elemental analysis. The constant of complex formation was calculated. By the IR spectroscopy the electron-donating centers of 5-hydroxyorotic acid taking part in coordination with metal ion were established. The structure of the obtained complex was suggested.     

铜(Ⅱ)络合纤维的配位结构与抗菌性

用蚕丝、粘胶纤维素、聚乙烯醇纤维在铜氨溶液中的多相配位取代反应制备了铜（Ⅱ）络合纤维．用电子自旋共振（ＥＳＲ）波谱等研究了铜（Ⅱ）络合纤维的配位结构．对金黄色葡萄球菌的抗菌实验表明：铜（Ⅱ）络合纤维的配位结构越不稳定抗菌性越强，但耐洗性将会下降．在此基础上设计了配位结构稳定性适中的柠檬酸修饰纤维素铜（Ⅱ）络合纤维     

Syntheses and crystal structures of nickel(II), copper(II), and zinc(II) complexes with a biphenyl-bridged bis(pyrrole-2-yl-methyleneamine) ligand

The reactions of nickel(II), copper(II), and zinc(II) acetate salts with a potentially tetradentate biphenyl-bridged bis(pyrrole-2-yl-methyleneamine) ligand yielded three complexes with different coordination geometries. X-ray crystal structural analysis reveals that in the nickel(II) complex each nickel is five-coordinate, distorted trigonal bipyramid. In the copper(II) complex, each copper is four-coordinate, between square planar and tetrahedral. In the zinc(II) complex, each zinc is four-coordinate with a distorted tetrahedral geometry and the molar ratio of the zinc and ligand is 1 : 2.     

Spectrochemical Properties of Noncubical Transition Metal Complexes in Solution. XII. Angular Overlap Studies of Salicylideneethylenediamine Cu(II) Complex in Various Solvents

As a part of our general interest in the UV-Vis spectroscopy of multidentate mixed-donor ligands, the (salicylideneethylenediamine)Cu(II) complex has been prepared and characterized by elemental analyses, solubility in common solvents, molar conductivities, and ultraviolet (UV), and visible (Vis) spectroscopy. The combined results of spectrophotometric measurements and EPR spectra, as well as known the X-ray structure for solids, were used to determine the structure of the investigated complex in solutions. The spectra of [Cu(salen)] (H₂salen = salicylideneethylenediamine), were measured in various solvents at room temperature, resolved by Gaussian analysis, and angular overlap model (AOM) treated in C _2v symmetry. Because of overparametrization problems, the bis(salicylaldehyde)Cu(II) complex has been characterized and AOM treated. The results of this have been used for AOM studies of [Cu(salen)]. The effect of the solvents upon the - and -bonding ligand abilities is discussed.     

EPR characterisation of Cu(II) complexes of poly(propylene imine) dendromesogens: using the orienting effect of a magnetic field.

Liquid-crystalline derivatives of poly(propylene imine)dendrimers of the 0th, 1st and 2nd generations, complexed with copper(II) ions, were studied by EPR spectroscopy. The structures of copper (II) complexes with different Cu(II) loadings x per dendrimer ligand L (x = Cu/L) were determined. At the lowest concentration, the Cu(II) ions form monomeric complexes with approximately square-planar N2O2 coordination of both carbonyl oxygen and amido nitrogen atoms. At higher copper content, two kinds of Cu(II) complex sites with different geometries exist. The orienting effect of a high magnetic field was used to investigate the structure and magnetic properties of the copper(II) complexes. This effect, for the first time in dendrimers, allowed the resolution of five nitrogen super-hyperfine lines on g(z) components with the unusual coupling constant of a(Nz)= 35.9 x 10(-4) cm(-1). The combination of the magnetic parameters and the orienting effect indicates the presence of a monomeric complex with pseudotetrahedral N2O2 coordination of the Cu(II) ion, as well as a "dimer" structure with fivefold coordination, presumably due to an N3O2 environment. Higher copper loadings lead to increased exchange coupling between the complex sites.     

Magnetic properties of poly(propylene imine)-copper dendromesogenic complexes: An EPR study.

Copper(II) complexes formed by coordination of the Cu(II) ion with liquid-crystalline poly(propylene imine) dendrimer ligand (L) of the first (complex 1) and second (complex 2) generations with various Cu(II) contents (x = Cu/L) have been studied by electron paramagnetic resonance (EPR) spectroscopy. The existence of a redox-active blue complex 1 (x = 1.9) and the copper(II) nitrate electron transfer associated with the valence tautomerism are revealed for the first time in copper-based dendrimers. It has been shown that the electronic structure of the blue complex 1 (x = 1.9) is adequately described as a mixed-valence dimer containing d9- and diamagnetic d10-configurated copper ions, and an antiferromagnetically coupled NO3* radical arising on the nitrate-bridged counter ligand. The activation energy value found for the electron transfer is about 0.35 meV, which indicates a low-energy charge dynamic. The ability of the blue and green complexes 1 (x = 1.9) dissolved in isotropic solvents to orient themselves in the magnetic field was revealed by EPR spectroscopy. The degree of orientation of the molecular z axis (S(z)) of these complexes in the magnetic field differs, depending on the type of copper(II)-complexing site in the dendrimer ligand, and can reach 0.76, which is close to S(z) = 1 (completely aligned system). A combination of magnetic and orientational parameters indicates an NO4 environment of the Cu(II) ion in green complex 1 (x = 1.9), and confirms the chain structure with intermolecular Cu(II)-NO3-Cu(II) bridges between Cu(II) centres in columns.     

含稀土铕(Ⅲ)配位聚合物的研究——铕(Ⅲ)噻吩甲酰三氟丙酮苯乙烯丙烯酸共聚物的研究

研究了铕 (Ⅲ )和噻吩甲酰三氟丙酮 (HTTA)形成的有机配合物与苯乙烯 丙烯酸共聚物 (PSAA)在不同pH值时发生配位反应得到配位聚合物NaEu(Ⅲ ) TTA PSAA的 3种样品 (a)、(b)、(c) .红外光谱、紫外光谱、X光电子能谱、DTA TG等测试手段证实Eu3+ 分别与PSAA、TTA- 发生配位 .元素分析和电导率测定结果证明了配位组成和结构在不同的pH条件下发生变化 .结果表明 ,配合物试样 (a)、(b)、(c)中Eu3+ 的含量分别为11 89%、12 5 5 %和 13 4 1% .由于配合物中存在着Eu3+ 分别与TTA- 和PSAA分子中羧基的配位作用并进一步交联 ,因此配合物样品均不溶于大部分有机溶剂 ,只能溶于N ,N 二甲基甲酰胺和丙三醇和异丙醇的混合溶剂 ,而且耐热性能均提高 .该配合物均是褐色固体 .荧光光谱表明 ,样品在常温、紫外光下发出强的红光 ,主要是Eu离子的5D0 →7F2 的跃迁 .讨论了溶剂、pH值对配合物荧光强度的影响 .当pH =10时 ,合成的配合物有最好的荧光性质 .     

Synthesis,Structure and Solvatochromism Studies on Copper(II) Complexes Containing Ethylenediamine,Pyridine and Imidazol Ligands

Two copper(II) complexes type [Cu(en)X₂](ClO₄)₂, where en = ethylenediamine and X = pyridine, 1 or imidazol, 2 have been synthesized and prepared on the bases of elemental analysis, spectroscopic and molar conductance measurements. The X‐ray crystal analysis of these complexes demonstrated that the copper(II) ions are in square planar environments through coordination by two nitrogen atoms of the ethylenediamine and two nitrogen atoms of two pyridine or imidazol molecules and the ClO₄^‐ ions are bound weakly above and below of the molecular plane. The complexes show three ions behavior in all solvents. The complexes are soluble in various solvents and are solvatochromic. The solvatochromism of the complexes were investigated by UV‐Vis spectroscopy with different solvent parameters such as DN, AN, α and β using multiple linear regression (MLR) method. The results suggested that the DN parameter of the solvent has the most contribution to the shift of the d‐d absorption band of the complex 1 but in complex 2 the DN and β have almost similar importance in the observed variation in the shift of the ν_max values with solvent nature.     

Complex of bis(hexafluoroacetylacetonato)copper(II) with a stable acyclic nitroxide (tert-butyl)(3-keto-2-methylbutyl-2) nitroxyl oxime

A complex of bis(hexafluoroacetylacetonato)copper(II) with a stable acyclic nitroxide (tert-butyl)(3-keto-2-methylbutyl-2)nitroxyl oxime (L), Cu(hfac)₂L, has been synthesized. The structure of the complex was studied by X-ray diffraction analysis. The compound has a molecular structure with chelate coordination of the nitroxide. The tetragonally distorted octahedral environment of the copper(II) ion is formed by the oxygen atoms of the hfac anions and by the nitrogen and oxygen atoms of the oxime and nitroxyl groups of L, respectively. The nitroxyl group lies in the equatorial plane of the octahedron (d_Cu?O=1.907 Å). This type of N?O coordination leads to strong antiferromagnetic exchange interactions between the unpaired electrons of the copper(II) ion and the coordinated nitroxyl group and, as a consequence, to diamagnetism of Cu(hfac)₂L.     

A recyclable nanosize aminoarenethiolato copper(I) catalyst for C-C coupling reactions

An aminoarenethiolato copper(I) catalyst was attached to a carbosilane dendritic wedge, which had been prepared via a novel convergent synthetic method. Compared with the unsupported complex, this novel dendritic copper(I) catalyst is more robust towards hydrolysis and oxidation and has increased solubility in common organic solvents. The catalytic activity of the dendritic copper catalyst was tested in the 1,4-addition of Et₂Zn to 2-cyclohexenone. In both polar (Et₂O) and apolar (hexane) solvents excellent activity was observed. The fact that the catalytic copper site remains attached to the nanosize dendritic aminoarenethiolate ligand allows separation of this catalyst by means of nanofiltration.     

Metal complexes of anxiolitic drugs. Crystal structure and electronic properties of dimeric oxalato complex of copper(II) bromazepam

Summary The title compound, has been prepared; its crystal structure, solved at room temperature, consists of dimer units bridged by oxalate lignads. Each copper ion is surrounded by two nitrogens of bromazepam and two oxygens of the oxalate ligand; a molecule of water occupies the apical site. The magnetic properties of the title compound have been investigated in the 30–300 K range. The molar magnetic susceptibility closely follows the behaviour expected for an antiferromagnetically coupled copper(II) binuclear complex with a singlet-triplet energy gap,J=–349 cm^–1.     

2-羟基-1-萘甲醛缩邻苯二胺席夫碱及其铜(Ⅱ)配合物的合成及组成测定——介绍一个大学化学综合实验

设计开发了一个大学化学综合性实验,合成了2-羟基-1-萘甲醛缩邻苯二胺席夫碱及其铜(Ⅱ)配合物,分别采用化学分析法和仪器分析法对配合物的组成进行了测定,并结合红外光谱、核磁共振氢谱对产物的结构进行了表征,取得了满意的实验结果。该实验一定程度上弥补了大学化学教学实验中合成有机金属配位化合物教学资源的匮乏。通过该实验的实施,可使学生进一步巩固回流、纯化、离心等基本操作技能,掌握摩尔比法测定配合物配位数及稳定常数的原理和方法,同时掌握运用有机波谱技术推断和鉴定分子结构的方法。本实验有利于培养学生综合运用有机化学、无机化学、化学分析及仪器分析等知识解决具体问题的能力,同时有利于学生了解席夫碱及其金属配合物的性质、研究动态等,激发学生对科学研究的热情,培养学生系统的科学思维和研究能力。     

A new mixed-ligand copper(II) complex containing azide and 1,10-phenanthroline: crystal structure and properties

A new copper complex, [Cu(phen)₂N₃]ClO₄ (phen = 1,10-phenanthroline), has been synthesized and characterized by X-ray single-crystal structure analysis. The copper atom is five-coordinated with four nitrogen atoms of two phens and one nitrogen atom of the azide to form an intermediate coordination geometry distorted from trigonal bipyramidal (TBP) and square pyramidal (SP). The extended three-dimensional structure is formed through π–π interactions and hydrogen bonds. The IR spectrum, electronic spectrum, magnetic properties and ESR spectrum of the title compound have been studied.     

X-ray structure of a novel histidine-copper(II) complex

A new crystal structure of the dichloro(L-histidine)copper(II) half-hydrate is reported. In this complex, histidine acts as a bidentate ligand to the copper(II) cation. The coordination sphere of the copper cation is created by the carboxyl oxygen and the amine nitrogen from main chain group of histidine. Two additional chloride anions complete the square coordination of the central Cu⁺² cation. In the crystal, the copper cations are additionally surrounded by two chloride anions from neighboring complex molecules, which are located in the distant axial position and fill up the stretched octahedral coordination sphere Cu⁺². In the presented complex, the histidine molecule exists as a zwitter ion with an unprotonated negatively charged carboxyl group and with double protonated positively charged imidazole ring. Crystallographic study was supported by IR measurements confirming the presence of water in the crystal structure.