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Synthesis,Characterisation and Reactivity of Copper(I) Amide Complexes and Studies on Their Role in the Modified Ullmann Amination Reaction 下载免费PDF全文
Simon Sung Dr. D. Christopher Braddock Prof. Alan Armstrong Dr. Colin Brennan Dr. David Sale Dr. Andrew J. P. White Dr. Robert P. Davies 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7179-7192
A series of copper(I) alkylamide complexes have been synthesised; copper(I) dicyclohexylamide ( 1 ), copper(I) 2,2,6,6‐tetramethylpiperidide ( 2 ), copper(I) pyrrolidide ( 3 ), copper(I) piperidide ( 4 ), and copper(I) benzylamide ( 5 ). Their solid‐state structures and structures in [D6]benzene solution are characterised, with the aggregation state in solution determined by a combination of DOSY NMR spectroscopy and DFT calculations. Complexes 1 , 2 and 4 are shown to exist as tetramers in the solid state by X‐ray crystallography. In [D6]benzene solution, complexes 1 , 2 and 5 were found by using 1H DOSY NMR to exist in rapid equilibrium between aggregates with average aggregation numbers of 2.5, 2.4 and 3.3, respectively, at 0.05 M concentration. Conversely, distinct trimeric, tetrameric and pentameric forms of 3 and 4 were distinguishable by one‐dimensional 1H and 1H DOSY NMR spectroscopy. Complexes 3 – 5 are found to react stoichiometrically with iodobenzene, in the presence or absence of 1,10‐phenanthroline as an ancillary ligand, to give arylamine products indicative of their role as potential intermediates in the modified Ullmann reaction. The role of phenanthroline has also been explored both in the stoichiometric reaction and in the catalytic Ullmann protocol. 相似文献
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《Journal of Coordination Chemistry》2012,65(4):351-359
Abstract The catalytic decomposition of hydrogen peroxide in the presence of the tetrakis(imidazole)copper(II) complex was investigated. The kinetics, based on the rates of oxygen evolution, indicated that a ternary copper(I1)-imidazole-peroxo complex is involved in the rate-determining step. The equilibrium constant for the coordination of hydrogen peroxide to the cupric ion, and the acid dissociation constant for the coordinated H202 ligand were calculated as 1.7 M1 and 2.1 × 109 M, respectively. The ternary complex undergoes intramolecular electron transfer, with k = 4 s1, generating Cu(1) species which can react with hydrogen peroxide or dioxygen, returning to the catalytic cycle. A complete mechanism is proposed, based on the kinetics of oxygen and on the electrocatalytic behdviour observed for the copperimidazole complexes under a dioxygen atmosphere. 相似文献
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A. Zuberbühler 《Helvetica chimica acta》1967,50(2):466-474
The autoxidation of two cuprous complexes, Cu(NH3)2+ and Cu(imidazole)2+, has been studied by following the oxygen consumption with a coated oxygen sensor, and the formation of CuII by means of a stopped flow technique. The reaction was found to be of third order being proportional to the concentrations of CuI, oxygen, and free ligand. pH variation was without effect in the range studied. The rate constants are kIM = 5,5 ·103 12· Mol?2·s?1 for imidazole, and kNH3 = 1,6·104 12· Mol?2· s?1 for NH3 as ligand, resp. An apparent activation energy of less than 2 Kcal/mole has been found for the autoxidation of the cuprous imidazole complex. This can be explained by the assumption of a rapidly playing equilibrium proceeding the rate determining step. 相似文献
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Dr. Michel Holler Dr. Béatrice Delavaux-Nicot Dr. Jean-François Nierengarten 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(18):4543-4550
Heteroleptic copper(I) complexes combining phenanthroline derivatives (NN) and chelating bisphosphine ligands (PP) are an important class of luminescent materials for various applications. Although thermodynamically stable, [Cu(NN)(PP)]+ derivatives are also kinetically unstable. As a result, a dynamic ligand-exchange reaction is often observed in solution, leading to a dynamic mixture of heteroleptic and homoleptic complexes. To prevent the formation of the homoleptic species, macrocyclic phenanthroline ligands have been used for the preparation of [Cu(NN)(PP)]+ pseudorotaxanes. The topological constraint resulting from the macrocyclic structure of the NN ligand drives the thermodynamic equilibrium towards the exclusive formation of the heteroleptic complex as long as the macrocycle is large and flexible enough to allow for the threading of the PP ligand. Conversely, when the threading is prevented by steric constraints, unprecedented copper(I) complexes with a trigonal coordination geometry are obtained. These results are summarized in the present concept article. 相似文献
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Nickel(II) and copper(II) complexes of 2,2’‐bibenzo[d]thiazole: Synthesis,characterisation and biological studies 下载免费PDF全文
Benzothiazole moiety has gained a lot of attention because of its importance as essential pharmacophore in the development of metal based drugs. Nickel(II) and copper(II) complexes of a benzothiazole based ligand, 2,2’‐bibenzo[d]thiazole (L1), synthesized by the reaction of benzothiazole‐2‐carbonylchloride and o‐aminothiophenol, is reported. The compounds were characterised by elemental and percentage metal analyses, spectroscopic (FTIR and UV–vis), 1H and 13C NMR, Mass spectra, thermal, magnetic moment and molar conductance analyses. The mass spectra, elemental and percentage metal composition of the metal complexes gave a 2:1 ligand to metal stoichiometric mole ratio. The spectral data showed that the ligand was coordinated to the metal ions through the nitrogen atoms of the benzothiazole moiety. The electronic spectra and magnetic susceptibility measurements showed that the nickel and copper complexes adopted square planar geometries. The ligand and its metal(II) complexes were screened against some drug resistant microbes and were found to exhibit varied degree of antimicrobial activities. The nickel complex was more active compared to ciprofloxacin against Staphylococcus aureus and Bacillus cereus. Similarly, the antioxidant potential of the ligand was evaluated. The ligand is a better ferrous ion chelating agent compared to 1,10‐phenanthroline and 2,2‐bipyridine. The ligand and its complexes exhibited good antimicrobial and Fe2+ chelating properties making them probable compounds of interest in antibiotic and antioxidant drug researches. 相似文献
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Long‐Lived Excited States of Zwitterionic Copper(I) Complexes for Photoinduced Cross‐Dehydrogenative Coupling Reactions 下载免费PDF全文
Dr. Bin Wang Dr. Deepak Prakash Shelar Xian‐Zhu Han Ting‐Ting Li Dr. Xiangguo Guan Prof. Dr. Wei Lu Dr. Kun Liu Prof. Dr. Yong Chen Prof. Dr. Wen‐Fu Fu Prof. Dr. Chi‐Ming Che 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1184-1190
Four heteroleptic copper(I) complexes containing phenanthroline and monoanionic nido‐carborane‐diphosphine ligands have been prepared and structurally characterized by various spectroscopic techniques and X‐ray diffraction. These complexes exhibit intense absorptions in the visible range and excited‐state lifetimes on the microsecond scale. Their application in visible‐light‐induced cross‐dehydrogenative coupling reactions was investigated. Preliminary studies showed that one of the four copper(I) complexes is an efficient catalyst for photoinduced oxidative C?H functionalization using oxygen as oxidant. Furthermore, α‐functionalized tertiary amines were obtained in good‐to‐excellent yields by light irradiation (λ>420 nm) of a mixture of our CuI complex, tertiary amines, and a variety of nucleophiles (nitroalkane, acetone, or indoles) under aerobic conditions. Electron paramagnetic resonance measurements provided evidence for the formation of superoxide radical anions (O2??) rather than singlet oxygen (1O2) during these photocatalytic reactions. 相似文献
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A Zuberbühler 《Helvetica chimica acta》1970,53(3):669-675
The autoxidation of the CuI-complexes with the chelating ligands histamine, histidine, carnosine, and histidylhistidine has been studied spectrophotometrically using a stopped flow setup. The reaction of these complexes is in general very rapid compared with the reactions of complexes of unidentate ligands studied earlier. It seems that for rapid autoxidation the formation of a CuII-like quadricoordinated transition state must be easy, and when the same number of similar ligand atoms are bound in the cuprous complex sterical factors seem to play an important role. 相似文献
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Maria Antonietta Zoroddu Serafino Gladiali Nadia Marchettini Roberto Dallocchio 《Transition Metal Chemistry》1995,20(4):351-355
Summary Complexes of Cu(glygly)phen ygly = glycylglycine; phen = 4,7-dimethyl [(1)], 5,6-dimethyl [(2)], 5-NO2[(3)], 5-Cl[(4)], 2-oxazolinyl (2-ox) [(5)] Phenanthroline and bis(2-oxazolinylphenanthroline)-copper(II) [(6)] were synthesized and characterized by conductivity measurements, e.p.r., i.r. and reflectance electronic spectroscopies.A broad u.v.-vis. band in the 620–640 nm range and a shoulder at ca. 825 nm suggest that these complexes are five-coordinate. The e.p.r. spectra indicate a stronger equatorial ligand field in the ternary complexes which is absent in the binary Cu-phen complexes, suggesting square pyramidal coordination, whose base contains the three donor atoms from glygly (O, N, N) and one donor from the phenanthroline nitrogen atom. The other nitrogen-containing ligand of the phenanthroline is in an apical position.The spectroscopic results can be correlated with electronic and steric effects attributable to the different substituents on the phenanthroline ligands.Only small variations in the structure of the ternary complexes occur as a function of the electronic effects of substituents on the aromatic phenanthroline ring ligands. Steric hindrance predominates in determining coordination geometry around copper(II). 相似文献
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Thomas Brandl Dr. Christoph Kerzig Dr. Loïc Le Pleux Dr. Alessandro Prescimone Prof. Oliver S. Wenger Prof. Marcel Mayor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(14):3119-3128
The development of molecular materials for conversion of solar energy into electricity and fuels is one of the most active research areas, in which the light absorber plays a key role. While copper(I)-bis(diimine) complexes [CuI(L)2]+ are considered as potent substitutes for [RuII(bpy)3]2+, they exhibit limited structural integrity as ligand loss by substitution can occur. In this article, we present a new concept to stabilize copper bis(phenanthroline) complexes by macrocyclization of the ligands which are preorganized around the CuI ion. Using oxidative Hay acetylene homocoupling conditions, several CuI complexes with varying bridge length were prepared and analyzed. Absorption and emission properties are assessed; rewardingly, the envisioned approach was successful since the flexible 1,4-butadiyl-bridged complex does show enhanced MLCT absorption and emission, as well as improved photostability upon irradiation with a blue LED compared to a reference complex. 相似文献
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Magdy Shebl 《Journal of Coordination Chemistry》2016,69(2):199-214
A new Schiff base, H2L, was prepared by condensation of 4,6-diacetylresorcinol with o-phenylenediamine in molar ratio 1?:?1. The ligand reacted with copper(II), nickel(II), cobalt(II), iron(III), zinc(II), oxovanadium(IV), and dioxouranium(VI) ions in the absence and presence of LiOH to yield mononuclear and homobinuclear complexes. The mononuclear dioxouranium(VI) complex [(HL)-(UO2)(OAc)(H2O)]·5H2O was used to synthesize heterobinuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, 1H-, and 13C-NMR, electronic, ESR and mass spectra, conductivity, and magnetic susceptibility measurements as well as thermal analysis. In the absence of LiOH, mononuclear complexes (1, 4, and 9) were obtained; in the presence of LiOH, binuclear complexes (3, 5, 7, and 10) as well as mononuclear complexes (2, 6, and 8) were obtained. In the mononuclear complexes, the coordinating sites are the phenolic oxygen, azomethine nitrogen, and amino nitrogen. In addition to these coordinating sites, the free carbonyl and phenolic OH are involved in coordination in binuclear complexes. The metal complexes exhibited octahedral, tetrahedral, and square planar geometries while the uranium is seven-coordinate. The antimicrobial and antioxidant activities of the ligand and its complexes were investigated. The ligand and the metal complexes showed antitumor activity against Ehrlich Acites Carcinoma. 相似文献
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Mixed ligand complexes of copper(II) with 8-hydroxyquinoline and various salicylic acids were isolated. Elemental analysis,
conductometric andIR data of these complexes were recorded. The esr and electronic spectral data of these complexes indicate distorted square
planar coordination for central copper ion. The σ bond and inplane π bond coefficients α2 and β2 respectively, of these complexes indicate partial covalency in the metal ligand bonding. The antimicrobial activity studies
show that the mixed ligand complexes act as more effective toxic agents thanbis (8-hydroxyquinolinato) copper(II) against certain bacteria and fungi. The lipophilic tendency of these complexes is determined
and its influence on their antimicrobial activity is critically examined. A probable mechanism for the antimicrobial activity
of these complexes is discussed
Presented at theXXII International Conference on Coordination Chemistry held at Budapest, Hungary, Aug 23–27, 1982 相似文献
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《Journal of Coordination Chemistry》2012,65(1-2):97-108
Abstract The synthesis of the new ligand 1,8-bis(quinolyloxy)-3,6-dithiaoctane (1) and the corresponding Cu(II), Cu(I) and Co(II) complexes is reported. The crystal and molecular structure of the copper(II) complex, [Cu(1)](ClO4)2.3H2O, has been determined by X-ray diffraction methods. The complex crystallizes in the orthorhombic space group Fddd, with cell data Z = 16, a = 20.326(2), b = 20.879(3) and c = 28.308(4)Å. The structure consists of discrete [Cu(1)]?2+ cations separated by (structurally disordered) perchlorate anions and three lattice water molecules per cation. The coordination geometry about the copper atom is pseudo-octahedral with the quinoline nitrogen and thioether sulfur atoms at the equatorial positions and the ether oxygen atoms at the axial positions. 1H NMR line-broadening experiments indicate that electron-transfer self-exchange reactions between the copper(I) and copper(II) complexes of (1) is immeasurably slow on the NMR time-scale. The coordination chemistry of (1) is compared with its oxygen analogue, 1,8-bis(quinolyloxy)-3,6-dioxaoctane. 相似文献
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Two copper(I) complexes [Cu(Cin2bda)2]ClO4 (I) and [Cu(Ncin2bda)2]ClO4 (II) have been prepared by the reaction of the ligands N2,N2′-bis(3-phenylallylidene)biphenyl-2,2′-diamine (L1) and N2,N2′-bis[3-(2-nitrophenyl)allylidene]biphenyl-2,2′-diamine (L2) and copper(I) salt. These compounds were characterized by CHN analyses, 1H NMR, IR, and UV-Vis spectroscopy. The C=N stretching frequency in the copper(I) complexes shows a shift to a lower frequency
relative to the free ligand due to the coordination of the nitrogen atoms. The crystal and molecular structure of II was determined
by X-ray single-crystal crystallography. The coordination polyhedron about the copper(I) center in the complex is best described
as a distorted tetrahedron. A quasireversible redox behavior was observed for complexes I and II.
The article is published in the original. 相似文献
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L. A. Vichreva T. A. Pudova N. N. Godovikov M. I. Kasachnik 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Cuprous dialkyl thiophosphates are convenient reagents for the synthesis of the organophosphorus compounds with the α-acetylenic bond in the alkthiolic radical, and for steric hindered S-propargyl thiophosphates. X-ray investigation established that the crystal is constructed of the tetramer molecules Cu4[(EtO)2PSO]4.1 The tetramer is a tetrahedral claster of Cu atoms coordinated with four three-dentant chelate-bridged diethyl thiophosphate ligands. Firmly coordinated diethyl thiophosphate ligand in the copper complex does not possess nucleophilic properties and does not react with alkyl bromide. EPR spectroscopy established that the ethynylation of cuprous dialkyl thiophosphate by the substituted ethynyl bromides proceeds via the paramagnetic cupric complex formation. The latter, being unstable under usual conditions, decomposes with the formation of substituted S-ethynyl thiophosphates and CuBr.2 Sterically hindered halides of the propargyl type are not liable to Sn2 reaction with the potassium salts of dialkyl thiophosphoric acids, but they readily react with the cuprous salts of these acids yielding S-propargyl thiophosphates. This process is a redox one and it proceeds via the paramagnetic cupric complex formation. 相似文献
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Pilar Souza Victoria Coto José R. Masaguer Agueda Arquero 《Transition Metal Chemistry》1987,12(5):400-403
Summary The Schiff base derived from 2-aminobenzimidazole and salicylaldehyde has been used to prepare a series of nickel(II) and copper(II) complexes. I.r., electronic spectra, elemental analyses, conductivity measurements and magnetic data have been utilized to determine the nature of these complexes.The results show that the base acts as bidentate ligand through the phenolic oxygen and the azomethine nitrogen in the non-polar form of the ligand or the pyridine-like imine nitrogen of imidazole ring in its zwitterionic form.One of the more striking differences between these compounds and those of other Schiffs bases(1,2) is the coordination spheres of the metal ions with this particular ligand. 相似文献
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Leila Rostami 《Journal of Coordination Chemistry》2017,70(21):3660-3676
Two copper(II) complexes with the general formula [Cu(L)(H2O)](ClO4)2 (1) and [Cu(L)2](ClO4)2 (2), where L=3-((pyridin-2-ylmethyl)amino)propanamide, were synthesized and characterized by elemental analyses, IR, UV–vis spectroscopy techniques and molar conductance measurements. The crystal structures of the complexes were identified by single crystal X-ray diffraction analysis. The tridentate ligand L acts as an N2O-donor through the nitrogen atoms of the pyridine and amine moieties as well the oxygen atom of the amide group. The copper(II) ions in both complexes have distorted octahedron structures so that the Cu(II) ion in 1 is coordinated by an aqua ligand and a tridentate ligand defining the basal plane, and by two oxygen atoms of the perchlorate ions occupying the axial positions. However, two ligands L are coordinated to the copper(II) ion in 2, where four nitrogen atoms of pyridine and amine groups occupy the equatorial positions and two oxygen atoms of the amide moieties exist in the apices. The chromotropism (halo-, solvato- and ionochromism) of both complexes were studied using visible absorption spectroscopy. The complexes are soluble in water and organic solvents and display reversible halochromism. The solvatochromism property is due to structural change followed by solvation of the vacant sites of the complexes. The complexes demonstrated obvious ionochromism and are highly sensitive and selective towards CN? and N3? anions in the presence of other halide and pseudo-halide ions. 相似文献
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Drug‐based mixed‐ligand copper(II) complexes of type [Cu(OFL)(An)Cl]·5H2O (OFL = ofloxacin, A1 = pyridine‐2‐carbaldehyde, A2 = 2,2′‐bipyridylamine, A3 = thiophene‐2‐carbaldehyde, A4 = 2,9‐dimethyl‐1,10‐phenanthroline, A5 = 2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline, A6 = 4,5‐diazafluoren‐9‐one, A7 = 1,10‐phenanthroline‐5,6‐dione and A8 = 5‐nitro‐1,10‐phenanthroline) were synthesized and characterized. Spectral investigations of complexes revealed square pyramidal geometry. Viscosity measurement and absorption titration were employed to determine the mode of binding of complexes with DNA. DNA cleavage study showed better cleaving ability of the complexes compared with metal salt and standard drug by conversion of a supercoiled form of pUC19 DNA to linear via circular. From the SOD mimic study, concentration of complexes ranging from 0.415 to 1.305 µM is enough to inhibit the reduction rate of NBT by 50% (IC50) in the NADH‐PMS system. Antibacterial activity was assayed against selective Gram‐negative and Gram‐positive microorganisms using the doubling dilution technique. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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《Journal of Coordination Chemistry》2012,65(2):227-242
Four new substituted amino acid ligands, N-(3-hydroxybenzyl)-glycine acid (HL1), N-(3-hydroxybenzyl)-alanine acid (HL2), N-(3-hydroxybenzyl)-phenylalanine acid (HL3), and N-(3-hydroxybenzyl)-leucine acid (HL4), were synthesized and characterized on the basis of 1H NMR, IR, ESI-MS, and elemental analyses. The crystal structures of their copper(II) complexes [Cu(L1)2]·2H2O (1), [Cu(L2)2(H2O)] (2), [Cu(L3)2(CH3OH)] (3), and [Cu(L4)2(H2O)]·H2O (4) were determined by X-ray diffraction analysis. The ligands coordinate with copper(II) through secondary amine and carboxylate in all complexes. In 2, 3, and 4, additional water or methanol coordinates, completing a distorted tetragonal pyramidal coordination geometry around copper. Fluorescence titration spectra, electronic absorption titration spectra, and EB displacement indicate that all the complexes bind to CT-DNA. Intrinsic binding constants of the copper(II) complexes with CT-DNA are 1.32?×?106?M?1, 4.32?×?105?M?1, 5.00?×?105?M?1, and 5.70?×?104?M?1 for 1, 2, 3, and 4, respectively. Antioxidant activities of the compounds have been investigated by spectrophotometric measurements. The results show that the Cu(II) complexes have similar superoxide dismutase activity to that of native Cu, Zn-SOD. 相似文献