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1.
Anurag Noonikara-Poyil Alvaro Muoz-Castro H. V. Rasika Dias 《Molecules (Basel, Switzerland)》2022,27(1)
Copper plays an important role in alkyne coordination chemistry and transformations. This report describes the isolation and full characterization of a thermally stable, copper(I) acetylene complex using a highly fluorinated bis(pyrazolyl)borate ligand support. Details of the related copper(I) complex of HC≡CSiMe3 are also reported. They are three-coordinate copper complexes featuring η2-bound alkynes. Raman data show significant red-shifts in C≡C stretch of [H2B(3,5-(CF3)2Pz)2]Cu(HC≡CH) and [H2B(3,5-(CF3)2Pz)2]Cu(HC≡CSiMe3) relative to those of the corresponding alkynes. Computational analysis using DFT indicates that the Cu(I) alkyne interaction in these molecules is primarily of the electrostatic character. The π-backbonding is the larger component of the orbital contribution to the interaction. The dinuclear complexes such as Cu2(μ-[3,5-(CF3)2Pz])2(HC≡CH)2 display similar Cu-alkyne bonding features. The mononuclear [H2B(3,5-(CF3)2Pz)2]Cu(NCMe) complex catalyzes [3 + 2] cycloadditions between tolyl azide and a variety of alkynes including acetylene. It is comparatively less effective than the related trinuclear copper catalyst {μ-[3,5-(CF3)2Pz]Cu}3 involving bridging pyrazolates. 相似文献
2.
A naringenin Schiff-base ligand (H3L) and its three complexes, MHL . nH2O (M = Zn and Cu, n = 0.5) and NiH2LOAc . 3.5H2O, have been synthesized and characterized on the basis of elemental analysis, molar conductivity and i.r. spectrum, 1H-n.m.r., u.v. spectra and thermal analyses. In addition, the suppression ratio for O2−˙ (a) and the suppression ratio for OH˙(b) were determined by the use of spectrophotometric methods. IC50(a) and IC50(b) of the complexes are given. The results show that compared to the ligand, the complexes exhibit high activity in the suppression
of O2−˙ (a) and OH˙(b). 相似文献
3.
New complexes of Cu(II), Zn(II) and Ni(II) with naringenin have been synthesized and characterized on the basis of elemental analyses, molar conductivities, 1H-n.m.r., i.r. spectra, u.v. spectra, thermal analyses, and fluorescence spectra. In addition, the suppression ratio for O2−· (a) and OH· (b) of the complexes were studied by spectrophotometric methods. The results show that the effect of the Cu(II)-complex IC50 (a) = 0.003 μm, IC50 (b) = 0.06 μm is the most remarkable, and the average scavenger ability of the complexes (IC50=0.06–2.67μm) against OH· is higher than that of the ligand (IC50 = 28.5 μm). Taken together, these results indicate that the scavenger effect can be enhanced by the formation of metal-ligand coordination
complexes, and the transition-metal ions may have differential and selective roles. 相似文献
4.
Gita Seth Vijaya Kabra Jasvinder Kaur Ritu Mathur Priti Kaushik 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1001-1010
New tetracoordinated complexes of Zn (II) have been synthesized by the reaction between zinc chloride and 3-methyl-2-benzothiazolylidenamido-thiophosphoryl dichloride (L1), (3-methyl-2-benzothiazolylidenamido)-bis-(diethylamido)thiophosphate (L2), 3-benzyl-2-benzothiazolylidenamido thiophosphoryl dichloride (L3), and (3-benzyl-2-benzothiazolylidenamido)-bis-(diethyl-amido) thiophosphate (L4) in a 1:1 ratio. The complexes have been isolated and characterized by elemental analysis, electrical conductivity, and mass and IR spectral studies. The stability constants of these complexes also have been determined in aqueous solution by spectrophotometric methods. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(12):1419-1426
In this study, 1,2-dihydroxyimino-3,7-di-aza-9,10-O-α-methyl benzal decane (LH2) was synthesized starting from 1,2-O-α-methyl benzal-4-aza-7-amino heptane (RNH2) and antichloroglyoxime. With this ligand, complexes were synthesized using Ni(II) and Cu(II) salts with a metal:ligand ratio of 1:2. However, the reaction of the ligand with salts of Zn(II) and Cd(II) gave products with metal:ligand ratio of 1:1. Structures of the ligand and its complexes are proposed based on elemental analyses, IR, 13C- and 1H-NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA). 相似文献
6.
Three mononuclear copper(II) complexes of copper nitrate with 2, 6‐bis(pyrazol‐1‐yl)pyridine ( bPzPy ) and 2, 6‐bis(3′,5′‐dimethylpyrazol‐1‐yl)pyridine ( bdmPzPy ), [Cu(bPzPy)(NO3)2] ( 1 ), [Cu(bPzPy)(H2O)(NO3)2] ( 2 ) and [Cu(bdmPzPy)(NO3)2] ( 3 ) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X‐ray structure analysis of complexes 1 and 2 revealed a five‐coordinate copper atom in 1 , whereas 2 contains a six‐coordinate (4+2) CuII ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H ··· O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D‐chains in a zipper‐like motif. 相似文献
7.
Some unusual oligonuclear copper(II) complexes with a bis(tridentate) pyrazolate‐based ligand that is composed of two diethylentriame‐type coordination compartments have been structurally characterized. In [(LCu2)2(CO3)(H2O)2(ClO4)](ClO4)3 ( 1 ), CO2 has been taken up and two {LCu2} subunits are spanned by both a μ3‐μ3‐κO:κO′:κO″‐bridging carbonate as well as by a μ3‐κO:κO′:κO″‐bridging perchlorate. The latter is a rare structural motif in coordination chemistry. In one experiment, a different complex [(LCu2(OH))2Cu2(OH)4](BF4)4 ( 2 ) has been serendipitiously obtained. One Cu atom of each {LCu2} subunit of 2 together with two further copper ions forms a pyrazolate‐appanded {Cu4(OH)4} cube. 相似文献
8.
Melyssa L. Grieve Patrick R. W. J. Davey Craig M. Forsyth Brett M. Paterson 《Molecules (Basel, Switzerland)》2021,26(12)
A 1,4,7,10-tetraazacyclododecane (cyclen) variant bearing two thiosemicarbazone pendant groups has been prepared. The ligand forms complexes with Mn2+, Co2+ and Zn2+. X-ray crystallography of the Mn2+, Co2+ and Zn2+ complexes showed that the ligand provides a six-coordinate environment for the metal ions. The Mn2+ and Zn2+ complexes exist in the solid state as racemic mixtures of the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,λ)/Λ(δ,δ,δ,δ) diastereomers, and the Co2+ complex exists as the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,δ)/Λ(δ,δ,δ,λ) diastereomers. Density functional theory calculations indicated that the relative energies of the diastereomers are within 10 kJ mol−1. Magnetic susceptibility of the complexes indicated that both the Mn2+ and Co2+ ions are high spin. The ligand was radiolabelled with gallium-68, in the interest of developing new positron emission tomography imaging agents, which produced a single species in high radiochemical purity (>95%) at 90 °C for 10 min. 相似文献
9.
SHARMA Guruaribam Shashikumar SHEIKH Rayees Ahmad SHREAZ Sheikh HASHMI Athar Adil KHAN Luqman Ahmad 《中国化学》2009,27(7):1300-1306
A new organoborate ligand, hydro(benzoyl)(phthalyl)borate has been synthesized as its potassium salt (KL) and treatment of KL with one equivalent of MCl2•6H2O gave complexes ML(H2O)x•Cl [x=2, M=Co(II), Ni(II); x=1, M=Cu(II)]. All compounds were characterized by elemental analysis, FTIR, 1H NMR, ESI MS, UV-Vis techniques, conductivity and magnetic data measurements. Spectroscopic results suggest a square planar geometry in the Cu(II) complex, while the Co(II) and Ni(II) complexes possess an octahedral geometry. Antibacterial activities (in vitro) of the ligand and its metal complexes were studied against two Gram positive (B. subtillis and B. magterium) and two Gram negative bacteria (E. Coli and S. boydi) at a single concentration (75 μg/mL) by using the Disc diffusion method. Antifungal activities (in vitro) were also checked for the compounds by using the same method against Candida albicans 10261, Penicillium sp. and Asperjillius niger., at a single concentration (50 μg/mL). The results showed that all the metal complexes, specially the nickel(II) complex, have higher antibacterial and antifungal activities than the corresponding potassium salt. 相似文献
10.
Gregory M. Ferrence Robert McDonald Josef Takats 《Angewandte Chemie (International ed. in English)》1999,38(15):2233-2237
Divalent and solvent-free : the ytterbium hydrido complex 1 was obtained by the hydrogenolysis of [(TptBu,Me)Yb(CH2SiMe3)(thf)]. The steric demand of the bulky hydrotris(3-tert-butyl-5-methylpyrazolyl)borate ligand, TptBu,Me, is sufficient to stabilize the dimer, yet facile room-temperature reactions with amines, alkynes, diynes, and CO indicate a rich chemistry of 1 . 相似文献
11.
Two new vic-dioxime ligands, (E,E)-N-{4-[(1,4-dioxaspiro[4.4]non-2-ylmethyl)amino]butyl}-N-hydroxy-2-(hydroxyimino)ethanimidamide (L1H2) and (E,E)-N-{4-[(1,4-dioxaspiro[4.5]dec-2-ylmethyl)amino]butyl}-N-hydroxy-2-(hydroxyimino)ethanimidamide (L2H2) containing two different heteroatoms (N,O) have been prepared from anti-chloroglyoxime, N-(1,4-dioxaspiro[4.4]non-2-ylmethyl)butane-1,4-diamine (3) and N-(1,4-dioxaspiro[4.5]dec-2-ylmethyl)butane-1,4-diamine (4). CoII, NiII and CuII complexes of the ligands have a metal:ligand ratio of 1:2 and the ligands coordinate through the two N atoms, as do most of the vic-dioximes. However, ZnII complexes of the ligands have a metal:ligand ratio of 1:1 and the ligands are coordinated only by the N, O atoms of the vic-dioximes. In the CoII complexes two water molecules, and in the ZnII complexes a chloride ion and a water molecule, are also coordinated to the metal ion. The structures of the compounds were determined by a combination of elemental analysis, magnetic moments, molar conductances, thermogravimetric analysis (t.g.a.) and spectroscopic (u.v.–vis., i.r., 1H- and 13C-n.m.r.) data. 相似文献
12.
Zhao Ming XUE* Yu Peng TIAN Dong WANG Min Hua JIANG Department of Chemistry Anhui University Hefei State Key Laboratory of Crystal Materials Shandong University Jinan 《中国化学快报》2003,(5)
In fluorescence imaging, two-photon excitation (TPE) has developed as an important alternative to traditional one-photon excitation (OPE) in fluorescence microscopy and spectroscopy1,2. The intrinsic advantages of the two-photon excitation include reduced background fluorescence from fluorophores outside the focal volume, decreased photobleaching, inherent optical sectioning capability, and lower photodamage of sensitive biological sample3. But, all the reported materials, which exhibit a … 相似文献
13.
14.
Renu Sharma Meena Nagar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1526-1535
A series of new mixed ligand complexes of Zn(II), Cd(II), and Hg(II) with citronellal thiosemicarbazone [3,7-dimethyl-6-octene-1-a1 thiosemicarbazone (LH)] and N-phthaloyl amino acids (AH) have been synthesized by the reaction of metal(II) chloride with ligands citronellal thiosemicarbazone (DOTSC) and N-phthaloyl glycine [1,3-dihydro-1,3-dioxo-2H-isoindole-2-acetic acid (A1H)] or N-phthaloyl alanine [1,3-dihydro-1,3-dioxo-α(methyl)-2H-isoindole-2-acetic acid (A2H)] in 1:1:1 molar ratio in dry refluxing ethanol. All the complexes have been characterized by elemental analyses, molar conductance measurement, molecular weight measurement, IR, and multinuclear NMR (1H and 13C{1H}) spectral studies. IR, 1H, and 13C{1H} NMR spectral studies suggest the involvement of azomethine-N, thiol-S atoms of the thiosemicarbazone moiety and both carboxylate-O of N-phthaloyl amino acid moiety in coordination with central metal(II) ion, and four coordinated geometries have been assigned to these complexes. The free ligands and metal complexes have been screened for their antifungal activity against two fungal strains, Fusarium moniliformae and Macrophomina phaseolina, using the the radial growth method. The results of antifungal activity show that metal complexes show enhanced higher activity than the free ligands. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
15.
Joanna Kobyłecka Bogdan Ptaszyński Anna Zwolinńska 《Monatshefte für Chemie / Chemical Monthly》2000,131(1):1-11
Summary. Sparingly water soluble complexes of lead(II), cadmium(II), and zinc(II) with N-phosphonomethylglycine (glyphosate, NPMG) of the general formulae C3H6O5NPPb, C3H6O5NPCdċ2H2O, and C3H6O5NPZn were synthesized. The complexes were also precipited from a dilute Roundup solution, and their solubility in water was
determined. Thermal, diffractometric, and IR spectrophotometric analyses were carried out. It was found that the metal is
bonded to glyphosate through the oxygen atoms of the carboxylic and phosphonate groups; metal-nitrogen binding is absent in
the above compounds. Studying the complexing behaviour in solution by UV spectrophotometry pointed out that a complex of the
composition Pb(II) : NPMG=1:1 with an absorption band at 232 nm is formed. Its stability constant as determined by Job’s method is logK=5.9±0.1. Using potentiometric techniques, the dissociation constant of N-phosphonomethylglycine and the stability constants
of its complexes with cadmium (II) and zinc (II) were determined.
Received June 30, 1999/Accepted July 21, 1999. 相似文献
16.
两个半夹心型聚吡唑硼酸盐羧酸钴配合物的合成、结构及催化活性 总被引:1,自引:0,他引:1
设计合成了2个结构新颖的半夹心单核聚吡唑硼酸盐羧酸配合物Tp*Co(Hglu)(CH3OH)(1)和Tp*Co(Hsub)(H2O)(2)[Tp*=三聚(3,5-二甲基吡唑)硼酸根, H2glu=戊二酸, H2sub=辛二酸], 并通过元素分析、 红外光谱、 紫外-可见光谱和X射线单晶结构分析对标题配合物进行了表征. 结构分析表明, 在配合物1和2中, 配体Tp*都是三齿配位, 配位模式相同; 戊二酸和辛二酸都以μ1-η1-η1的端基配位模式与金属相连. 此外, 还对配合物的热稳定性进行了详细分析, 并初步探讨了配合物催化氧化环己烷的催化活性. 相似文献
17.
Valentina Iannace Dr. Ferran Sabaté Molly Bartlett Dr. Jessica Berrones Reyes Dr. Ariadna Lázaro Alessia Fantoni Prof. Ramon Vilar Prof. Laura Rodríguez Prof. Antonella Dalla Cort 《欧洲无机化学杂志》2023,26(28):e202300144
Three series of metal salophen complexes derived from Zn2+, Cu2+, Pt2+ and Ni2+ have been synthesized and their interaction with quadruplex DNA has been evaluated. The compounds differ on the number of ethyl piperidine substituents. They have been characterized by 1H NMR, IR and UV-visible spectroscopies and by HR-mass spectrometry. Their luminescent properties have been also evaluated and we can observe that, as expected, Zn2+ and Pt2+ complexes are those displaying more interesting luminescence with an emission band red-shifted with respect to the corresponding uncoordinated ligand. DNA interactions with G4 and duplex DNA were evaluated by FRET melting assays (for the Zn2+, Cu2+ and Ni2+ complexes) and by emission titrations (for one Pt2+ complex) which indicated that the disubstituted compounds 2-Ni and 2-Pt are the only ones that display good affinity for G4 DNA structures. 相似文献
18.
Naresh Eedugurala Zhuoran Wang Uddhav Kanbur Arkady Ellern Marek Pruski Aaron D. Sadow 《Helvetica chimica acta》2021,104(2):e2000209
The reaction of ToMTl (ToM=tris(4,4-dimethyl-2-oxazolinyl)phenylborate) and CuBr2 in benzene at 60 °C provides ToMCuBr ( 1 ) as an entry-point into tris(oxazolinyl)phenylborato copper chemistry. ToMCuOtBu ( 2 ) and ToMCuOAc ( 3 ) are prepared by the reactions of ToMCuBr with KOtBu and NaOAc, respectively. ToMCuOtBu is transformed into (ToMCuOH)2 ( 4 ) through hydrolysis. NMR, FT-IR, and EPR spectroscopies are used to determine the electronic and structural properties of these copper(II) compounds, and the solid-state structures were characterized by X-ray crystallography. Reduction of copper is observed upon treatment of ToMCuOtBu with phenylsilane in an attempt to synthesize monomeric copper(II) hydride. ToMCu ( 5 ) and ToM2Cu ( 6 ) were independently synthesized and characterized for comparison. 相似文献
19.
Luca Bagnarelli Alessandro Dolmella Carlo Santini Riccardo Vallesi Roberto Giacomantonio Serena Gabrielli Maura Pellei 《Molecules (Basel, Switzerland)》2021,26(20)
A new dimeric copper(II) bromide complex, [Cu(LOHex)Br(μ-Br)]2 (1), was prepared by a reaction of CuBr2 with the hexyl bis(pyrazol-1-yl)acetate ligand (LOHex) in acetonitrile solution and fully characterized in the solid state and in solution. The crystal structure of 1 was also determined: the complex is interlinked by two bridging bromide ligands and possesses terminal bromide ligands on each copper atom. The two pyrazolyl ligands in 1 coordinate with the nitrogen atoms to complete the Cu coordination sphere, resulting in a five-coordinated geometry—away from idealized trigonal bipyramidal and square pyramidal geometries—which can better be described as distorted square pyramidal, as measured by the τ and χ structural parameters. The pendant hexyloxy chain is disordered over two arrangements, with final site occupancies refined to 0.705 and 0.295. The newly synthesized complex was evaluated as a catalyst in copper-catalyzed C–H oxidation for allylic functionalization through a Kharasch–Sosnovsky reaction without any external reducing agent. Using 0.5 mol% of this catalyst, and tert-butyl peroxybenzoate (Luperox) as an oxidant, allylic benzoates were obtained with up to 90% yield. The general reaction time was only slightly decreased to 24 h but a very significant decrease in the alkene:Luperox ratio to 3:1 was achieved. These factors show relevant improvements with respect to classical Kharasch–Sosnovsky reactions in terms of rate and amount of reagents. The present study highlights the potential of copper(II) complexes containing functionalized bis(pyrazol-1-yl)acetate ligands as efficient catalysts for allylic oxidations. 相似文献
20.
Kunavina E. A. Koz’minykh V. O. Sizentsov A. N. Salikova E. V. Rusyaeva M. L. Korol’kova D. S. 《Russian Journal of General Chemistry》2019,89(1):67-70
Russian Journal of General Chemistry - The condensation of aryl methyl ketones with diethyl oxalate in the presence of metallic sodium or sodium hydride gave sodium... 相似文献