共查询到20条相似文献,搜索用时 15 毫秒
1.
Dr. Angelo Frei Dr. A. Paden King Gabrielle J. Lowe Dr. Amy K. Cain Dr. Francesca L. Short Hue Dinh Dr. Alysha G. Elliott Dr. Johannes Zuegg Prof. Justin J. Wilson Assoc. Prof. Mark A. T. Blaskovich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(6):2021-2029
Resistance to currently available antifungal drugs has quietly been on the rise but overshadowed by the alarming spread of antibacterial resistance. There is a striking lack of attention to the threat of drug-resistant fungal infections, with only a handful of new drugs currently in development. Given that metal complexes have proven to be useful new chemotypes in the fight against diseases such as cancer, malaria, and bacterial infections, it is reasonable to explore their possible utility in treating fungal infections. Herein we report a series of cobalt(III) Schiff base complexes with broad-spectrum antifungal activity. Some of these complexes show minimum inhibitory concentrations (MIC) in the low micro- to nanomolar range against a series of Candida and Cryptococcus yeasts. Additionally, we demonstrate that these compounds show no cytotoxicity against both bacterial and human cells. Finally, we report the first in vivo toxicity data on these compounds in Galleria mellonella, showing that doses as high as 266 mg kg−1 are tolerated without adverse effects, paving the way for further in vivo studies of these complexes. 相似文献
2.
Two cobalt(Ⅱ) complexes of the Schiff base with morpholino or aza-crown ether pendants, CoL^1 and CoL^2, as mimic hydrolytic metalloenzyme, were used in catalytic hydrolysis of carboxylic ester (PNPP). The analysis of specific absorption spectra of the hydrolytic reaction systems indicates that key intermediates, made up of PNPP and Co(Ⅱ) complexes, have been formed in reaction processes of the PNPP catalytic hydrolysis. The mechanism of PNPP catalytic hydrolysis has been proposed based on the analytic result of specific absorption spectrum. A kinetic mathematical model, applied to the calculation of the kinetic parameter of PNPP catalytic hydrolysis, has been established based on the mechanism proposed. The acid effect of buffer solution, structural effect of the complexes, and effect of temperature on the rate of PNPP hydrolysis catalyzed by the complexes have been also discussed. 相似文献
3.
Matilde Fondo Ana M. García Deibe Noelia Ocampo Manuel R. Bermejo Jesús Sanmartín 《无机化学与普通化学杂志》2005,631(11):2041-2045
The heptadentate Schiff base H3L reacts with cobalt(II) acetate in methanol to form the discrete dinuclear complex Co2L(OAc)2(OMe)(H2O)2 ( 1 ·2H2O). The reaction of 1 ·2H2O with NMe4OH·5H2O in methanol gives rise to displacement of the acetate by methanolate groups, yielding Co2L(OMe)3(H2O) ( 2 ·1H2O). Recrystallizations of the Schiff base, 1 ·2H2O and 2 ·H2O in different solvents, produce single crystals of H3L, 1 ·2.5H2O and 2 ·2MeOH, respectively. The crystal structures of 1 ·2.5H2O and 2 ·2MeOH show the cobalt atoms double bridged by and endogenous phenol oxygen atom and an exogenous methanolate oxygen donor, giving rise to Co2O2 cores with Co···Co distances of ca. 2.87 Å. 相似文献
4.
Wei Hu Jian-zhang Li Ying Wang Ju Du Chang-wei Hu 《Journal of Dispersion Science and Technology》2013,34(10):1476-1483
The two Schiff base cobalt(II) complexes, CoL1 and CoL2, were synthesized and characterized. The metallomicelle made up of the cobalt(II) complexes and surfactants (CTAB, LSS and Brij35), as mimic peroxidase metalloenzyme, were used in the catalytic oxidation of phenol by H2O2. The mechanism and a kinetic mathematic model of the phenol catalytic oxidation were studied. The acid effect of reaction system, structural effect of the complexes, and effect of temperature on the rate of the phenol oxidation catalyzed by the mimetic peroxidases have been discussed. The results showed that the schiff base cobalt(II) complexes and their metallomicelles as peroxidase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme. 相似文献
5.
双水杨醛缩乙二胺烷基钴(Ⅲ)配合物电化学氧化动力学的研究 总被引:1,自引:0,他引:1
用循环伏安法、计时电流法、线性扫描伏安法及lgi~E法研究了双水杨醛缩乙二胺烷基钴(Ⅲ)配合物[RCo(Salen),R=CH3,C2H5,n-C4H9,i-C4H9]在Au电极上的电化学氧化动力学过程,测定了RCo(Salen)的电极反应的速率常数ks、电子转移数n1、电荷传递系数a、标准电极电位E0、扩散系数D;同时,还测定了氧化产物化学分解加速率常数kf及分解产物电解氧化的电子转移数n2等参数,实验表明RCo(Salen)的电化学反应是ECE过程,R基对E0、kf等均有影响。 相似文献
6.
香草醛缩多胺Schiff碱Co(II)配合物固相合成及氧合性能研究 总被引:4,自引:0,他引:4
采用固相反应合成了三个新的席夫碱钴(II)配合物, 在室温下, 将其与O2作用, 1 mol配合物吸收2 mol O2, 得到三种固态氧合配合物[Co•(L1)2•(O2)2](NO3)2•2H2O [L1=N,N-二(4-羟基-3-甲氧基苯亚甲基)二乙烯三胺], [Co•(L2)2•(O2)2](NO3)2•2H2O [L2=N,N-二(4-羟基-3-甲氧基苯亚甲基)三乙烯四胺]和[Co•(L3)2•(O2)2](NO3)2•2H2O (L3=N,N-二(4-羟基-3-甲氧基苯亚甲基)四乙烯五胺]. 通过元素分析、红外光谱、核磁共振氢谱(1H NMR), TG/DTA、摩尔电导率、紫外等测试手段确定了氧合配合物的组成. 采用失重法测定了氧合配合物中的配位氧, 确定1 mol钴配合物吸收2 mol O2, 其中1 mol O2用来和钴离子配位形成超氧配合物. 相似文献
7.
Summary. The mechanisms of photoinduced processes occurring in methanolic solutions of trans-[Fe(4-R-benacen)(CH3OH)I] (4-R-benacen
2− : N,N′-ethylene-bis-(4-R-benzoylacetoneiminato) tetradentate open-chain Schiff bases with R = H, Cl, Br, CH3, OCH3, or NO2) were investigated by electronic absorption spectroscopy and EPR spin trapping. The complexes are redox-stable in the dark
both in the solid state and in methanolic solutions. Ultraviolet and/or visible irradiation in methanol induces photoreduction
of Fe(III) to Fe(II). No formation of I˙ or was observed. ˙CH2OH radicals and/or solvated electrons were identified in irradiated systems using nitrosodurene or 5,5-dimethyl-1-pyrroline-N-oxide
as spin traps. The final product of the photooxidation coupled with the photoreduction of Fe(III) is formaldehyde, the molar
ratio of Fe(II) and CH2O being close to 2:1. The efficiency of the photoredox process is strongly wavelength dependent and influenced by the peripheral
groups R of the tetradentate ligands. It is suggested that the primary photoredox step starts from thermally nonequilibrated ligand-to-metal
charge transfer excited states.
Received May 2, 2001. Accepted May 30, 2001 相似文献
8.
Three linear trinuclear Schiff base complexes, {Zn[Zn(CH3COO)(C17H16N2O2)]2} ( 1 ), {Zn[Zn(CH3COO)(C25H20N2O2)]2} ( 2 ), and {Cd[Cd(CH3COO)(C18H18N2O2)]2} ( 3 ), were synthesized for the first time under solvolthermal conditions. Their structures have been characterized by elemental analyses, X-ray single crystal determinations, and infrared spectroscopy. There are three bridges across the M-M atom pairs (M is Zn for 1 and 2 , or Cd for 3 ) in each complex, involving two O atoms of a Schiff base ligand (N,N′-bis(salicylidene)-1, 3-propanediaminate (SALPD2-) for 1 , N, N′-bis(2-hydroxy-naphthalmethenylimino)-1, 3-propanediaminate (NAPTPD2-) for 2 , and N,N′-bis-(salicylidene)-1,4-butanediaminate (SALBD2-) for 3 ), and an O-C-O moiety of a μ-acetato group. In each of the complexes, the central M2+ ion is located on an inversion center and has a distorted octahedral coordination involving four bridging O atoms from two Schiff base ligands in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal M2+ ions is irregular square pyramidal, with two O atoms and two N atoms of the Schiff base ligand in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal M2+ ions are mutually trans. The M…M distances are 3.050(3) Å in 1 , 3.139(2) Å in 2 , and 3.287(6) Å in 3 . 相似文献
9.
M. I. Fernndez García M. Fondo A. M. García Deibe M. B. Fernndez Fernndez A. M. Gonzlez 《无机化学与普通化学杂志》2000,626(9):1985-1991
New copper(II) complexes of asymmetrical tetradentate Schiff bases containing pyrazine have been prepared and thoroughly characterised by elemental analysis, IR and electronic spectroscopy, mass spectrometry and magnetic measurements. Two alternative methods were used in the isolation of the complexes: template synthesis in the preparation of Cu(SalDpyz)ClO4 (HSalDPyz = derived from the condensation of salicylaldehyde, acetylpyrazine and 1,2‐ethylendiamine, 2‐methyl‐1,2‐propylendiamine, 1,2‐phenylendiamine) and direct interaction between copper perchlorate and the corresponding Schiff base, as in the isolation of Cu(AEPyz)(ClO4) (HAEPyz = (Z)‐4‐[2‐{[2‐{[(E)‐1‐(pyrazinyl)ethylidene]amino} ethyl)amino]‐3‐penten‐2‐one)]. [Cu(SalEn)(py)(OClO3)][Cu(SalEn)(py)]ClO4 ( 1 ) (SalEn = 4‐(2‐hydroxyphenyl)‐3‐aza‐3‐buten‐1‐amino, py = pyridine), metal precursor in the preparation of Cu(SalEnpyz)(ClO4) (HSalEnpyz = 2‐{E(2‐{[(E)‐1‐(2‐pyrazinyl)ethylidene]amino}ethyl)imino]methyl}phenol), was crystallographically characterised. The crystal structure of [Cu(AEpyz)]ClO4 ( 2 ) is also reported. 相似文献
10.
Efficient Water Oxidation Catalyzed by Mononuclear Ruthenium(II) Complexes Incorporating Schiff Base Ligands 下载免费PDF全文
Ting‐Ting Li Prof. Dr. Yong Chen Fu‐Min Li Wei‐Liang Zhao Chuan‐Jun Wang Dr. Xiao‐Jun Lv Dr. Quan‐Qing Xu Prof. Dr. Wen‐Fu Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):8054-8061
Four new charge‐neutral ruthenium(II) complexes containing dianionic Schiff base and isoquinoline or 4‐picoline ligands were synthesized and characterized by NMR and ESI‐MS spectroscopies, elemental analysis, and X‐ray diffraction. The complexes exhibited excellent chemical water oxidation activity and high stability under acidic conditions (pH 1.0) using (NH4)2Ce(NO3)6 as a sacrificial electron acceptor. The high catalytic activities of these complexes for water oxidation were sustained for more than 10 h at low concentrations. High turnover numbers of up to 3200 were achieved. A water nucleophilic attack mechanism was proposed. A RuV?O intermediate was detected during the catalytic cycle by high‐resolution mass spectrometry. 相似文献
11.
M. Jesús Rodríguez M. Isabel Fernndez Ana M. Gonzlez‐Noya Marcelino Maneiro Rosa Pedrido Miguel Vzquez Bruno Donnadieu Manuel R. Bermejo 《无机化学与普通化学杂志》2005,631(11):2161-2166
M(HL)(H2O)n complexes have been obtained by the electrochemical reaction of Fe, Co, Ni, Cu, Zn and Cd anodes with the potentially pentadentate and trianionic asymmetrical Schiff base 3‐aza‐N‐{2‐[1‐aza‐2‐(5‐nitro‐2‐hydroxylphenyl)‐vinyl]phenyl}‐4‐(5‐nitro‐2‐hydroxyphenyl)but‐3‐enamide (H3L), containing a hard amido donor atom. The complexes have been characterized by elemental analysis, mass spectrometry, IR and 1H NMR spectroscopies, magnetic measurements and molar conductivities. Co(HL)(H2O) ( 2 ) has been found to rearrange in DMF solution into a crystallographically solved octahedral complex, CoL1(H2O)2 ( 7 ) [where H2L1 is the symmetrical Schiff base ligand N,N′‐(1,2‐phenylene)‐bis(5‐nitro‐3‐hydroxysalicylidenimine)]. A hydrolysis mechanism is discussed to explain this rearrangement. 相似文献
12.
Yuko Hasegawa Shuhei Saitou Sayaka Tamaki Hirofumi Yajima Makoto Tadokoro 《Helvetica chimica acta》2009,92(11):2565-2575
The UV, excitation, and luminescence spectra of tris(pivaloyltrifluoroacetonato)europium(III) ([Eu(pta)3]; Hpta=1,1,1‐trifluoro‐5,5‐dimethylhexane‐2,4‐dione=HA) were measured in the presence of bis(salicylidene)trimethylenediamine (H2saltn), bis[5‐(tert‐butyl)salicylidene]trimethylenediamine (H2(tBu)saltn), or bis(salicylidene)cyclohexane‐1,2‐diyldiamine (H2salchn), and the corresponding ZnII complexes [ZnB] (B=Schiff base). The excitation and luminescence spectra of the solution containing [Eu(pta)3] and [Zn(salchn)] exhibited much stronger intensities than those of solutions containing the other [ZnB] complexes. The introduction of a tBu group into the Schiff base was not effective in sensitizing the luminescence of [Eu(pta)3]. The luminescence spectrum of [ZnB] showed a band around 450 nm. The intensity decreased in the presence of [Eu(pta)3], reflecting complexation between [Eu(pta)3] and [ZnB]. On the basis of the change in intensity against the concentration of [ZnB], stability constants were determined for [Eu(pta)3Zn(saltn)], [Eu(pta)3Zn{(tBu)saltn}], and [Eu(pta)3Zn(salchn)] as 4.13, 4.9 and 5.56, respectively (log , where =[[Eu(pta)3ZnB]]([[Eu(pta)3]][[ZnB]])?1). The quantum yields of these binuclear complexes were determined as 0.15, 0.11, and 0.035, although [Eu(pta)3Zn(salchn)] revealed the strongest luminescence at 613 nm. The results of X‐ray diffraction analysis for [Eu(pta)3Zn(saltn)] showed that ZnII had a coordination number of five and was bridged with EuIII by three donor O‐atoms, i.e., two from the salicylidene moieties and one from the ketonato group pta. 相似文献
13.
Prof. Dr. Seyed A. Hosseini‐Yazdi Ali A. Khandar Mir Kh. Tabatabai Leila Noohinejad 《无机化学与普通化学杂志》2010,636(15):2650-2657
Dizinc(II) complexes of two acyclic Schiff‐base ligands L1 – and L2 – were synthesized by Schiff base condensation of 2‐[3‐(2‐formylphenoxy)‐2‐hydroxypropoxy]benzaldehyde ( PL ) with 1,2‐diaminopropane and 1,2‐diaminoethane, respectively, in the presence of zinc(II) salts. The isolation of a selection of 2:1 (metal:ligand) complexes of zinc(II) was carried out and conductance measurements, IR, UV/Vis absorption, and fluorescence emission spectroscopy, as well as X‐ray diffraction were employed to probe the nature of the respective complexes in both solid and solution states. The molecular structure of [Zn2 L1 (NO3)3] ( 1 ) complex consists of two six‐coordinate atoms, which are bridged by the deprotonated hydroxy group and one 1,3‐bridging nitrate anion. The structure of [Zn2 L2 (NO3)(H2O)2](NO3)2 · CH3OH ( 3 ) consists of a dizinc cation and two nitrate anions as counterions. In compound 3 , each zinc atom is bound to water instead of a terminal nitrate anion in a distorted octahedral arrangement. The intermetallic separation distance of Zn ··· Zn in 3 (3.376 Å) is slightly smaller than 1 (3.403 Å) and is similar to that found in zinc phosphotriesterase (3.5 Å). The π–π interactions between the benzene rings of adjacent molecules in 3 are stronger than in 1 . 相似文献
14.
Chi‐Ming Che Prof. Dr. Chi‐Chung Kwok Dr. Siu‐Wai Lai Dr. Andreas F. Rausch Dipl.‐Chem. Walter J. Finkenzeller Dr. Nianyong Zhu Dr. Hartmut Yersin Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(1):233-247
The syntheses, crystal structures, and detailed investigations of the photophysical properties of phosphorescent platinum(II) Schiff base complexes are presented. All of these complexes exhibit intense absorption bands with λmax in the range 417–546 nm, which are assigned to states of metal‐to‐ligand charge‐transfer (1MLCT) 1[Pt(5d)→π*(Schiff base)] character mixed with 1[lone pair(phenoxide)→π*(imine)] charge‐transfer character. The platinum(II) Schiff base complexes are thermally stable, with decomposition temperatures up to 495 °C, and show emission λmax at 541–649 nm in acetonitrile, with emission quantum yields up to 0.27. Measurements of the emission decay times in the temperature range from 130 to 1.5 K give total zero‐field splitting parameters of the emitting triplet state of 14–28 cm?1. High‐performance yellow to red organic light‐emitting devices (OLEDs) using these platinum(II) Schiff base complexes have been fabricated with the best efficiency up to 31 cd A?1 and a device lifetime up to 77 000 h at 500 cd m?2. 相似文献
15.
Six new nickel(II) complexes of the unsymmetrical Schiff base ligands derived from o‐phenylenediamine were synthesized. These complexes were prepared by template and non‐template reactions of the precursor 3‐acetyl‐4‐[N‐(2'‐aminophenyl)‐amino]‐3‐buten‐2‐one ( HL °) with appropriate o‐hydroxycarbonyl aromatic compounds, aromatic 1, 3‐oxo aldehydes and 1, 3‐diketones. The nickel(II) compounds were characterized by analytical and spectroscopic methods. Crystal structure of complex [3‐acetyl‐(6, 7)‐benzo‐8‐salicylidene‐5, 8‐diazahepta‐3‐ene‐2‐onato(2‐)]nickel(II) ( NiL 1) has been determined by X‐ray powder diffraction method, revealed that the molecules are almost flat, and there are no forces other than van der Waals interactions between molecules. The structure was solved by global optimisation technique and refined by the Rietveld method, obtained RF and Rwp are 11.6 and 17.4%, respectively. The synthesis of a new unsymmetrical nickel(II) tetraazamacrocyclic complex is also described. 相似文献
16.
Zhihua Chen Makoto Furutachi Yuko Kato Shigeki Matsunaga Dr. Masakatsu Shibasaki Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(12):2218-2220
Two metal cooperation : A homodinuclear Co2–Schiff base complex Co2(OAc)2– 1 promoted the asymmetric 1,4‐addition of β‐keto esters to alkynones under solvent‐free conditions in air (see scheme). The reactions proceeded without air or moisture sensitivity in high yields and with high enantioselectivities (99–91 % ee) at room temperature under highly concentrated conditions (neat–20 M ) with 0.1–2.5 mol % catalyst loading.
17.
Karuna Mahajan Monika Swami R. V. Singh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2664-2679
Tetra- and pentacoordinated antimony and bismuth derivatives have been prepared by the interactions of monophenylantimonydichloride(III), trichlorostibane, and trichlorobismuthane with the sodium salts of 3-(indolin-2-one)hydrazinecarbothioamide (L1H) and 3-(indolin-2-one)hydrazinecarboxamide (L2H), under microwave irradiation as well as by conventional heating. These compounds were further characterized by analytical and spectroscopic techniques including UV, IR, 1H NMR, and 13C NMR spectra. Newly synthesized complexes with their corresponding ligands were also tested for their antifungal and antibacterial activities. 相似文献
18.
Reactivity of a Zn(Cys)2(His)2 Zinc Finger with Singlet Oxygen: Oxidation Directed toward Cysteines but not Histidines 下载免费PDF全文
Vincent Lebrun Arnaud Tron Colette Lebrun Dr. Jean‐Marc Latour Dr. Nathan D. McClenaghan Dr. Olivier Sénèque 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14002-14010
19.
20.
The thermal decomposition using TG, DTG and DTA, of seven complexes of the types Bu2SnL(I) and Bu2SnL(II) (where H2L(I)=Schiff base derived from acetylacetone and glycine [H2L-1(I)] or L-leucine [H2L-4(I)] or methionine [H2L-5(I)] or phenylglycine [H2L-6(I)]; H2L(II)=Schiff base derived from o-hydroxynaphthaldehyde and β-alanine [H2L-2(II)] or DL-valine [H2L-3(II)] or L-leucine [H2L-4(II)] is shown to fall into one of two categories, viz, (1) Bu2SnL(I) complexes that decompose without melting to give SnO as the final tin containing product, (2) Bu2SnL(II) complexes that melt and then decompose to give SnO. Mathematical analysis of TG data using Coats-Redfern equation,
Horowitz-Metzger equation, and Fuoss method shows that the first order kinetics is applicable in all the complexes except
Bu2SnL-2(II). Kinetic parameters such as the energy and entropy of activation and pre-exponential factor are reported.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献