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1.
Zeinab Abbasi Maciej Kubicki Ali Khaleghian 《Journal of Coordination Chemistry》2017,70(12):2074-2093
Four novel Schiff base ligands and their copper(II) complexes, [Cu(L1)2] (1), [Cu(L2)2] (2), [Cu(L3)2] (3), and [Cu(L4)2] (4), were synthesized and characterized by elemental analyses, FT-IR, and UV–Vis spectroscopy. The ligands were synthesized from the condensation of 2-methoxyethylamine with various salicylaldehyde derivatives (x-salicylaldehyde for HLn, x = H (n = 1), 5-Br (n = 2), 3-OMe (n = 3), and 4-OMe (n = 4)). The molecular structures of 1, 2, and 3 were determined by the single crystal X-ray diffraction technique. The redox behavior studies of the complexes in acetonitrile display the electronic effects of the groups on the redox potential. The antioxidant activity of the Schiff base ligands and their Cu(II) complexes was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method and FRAP assay. Furthermore, the in vitro anticancer activity of compounds was screened, including MTT and migration assays against gastric cancer cell line (MKN-45). The results show that all ligands and complexes have antioxidant and anticancer activity in a concentration-dependent way. 相似文献
2.
C. Menapace I. Lonardelli A. Molinari 《Journal of Thermal Analysis and Calorimetry》2010,101(3):815-821
New complexes of type [Cu(HTBG)2]Cl2 (1), [Cu(TBG)2]·3H2O (2) and [CuL]·nH2O (3) L:L1, n = 2 and (4) L:L2, n = 1 (HTBG: 2-tolylbiguanide, L1 and L2: ligands resulted from 2-tolylbiguanide, ammonia/hydrazine and formaldehyde one pot condensation) were synthesised and characterised.
The features of complexes have been assigned from microanalytical, IR and UV–Vis data. Redox behaviour was established by
cyclic voltammetry. The in vitro qualitative and quantitative antimicrobial activity assays showed that the complexes exhibited
variable antimicrobial activity against Gram-negative and Gram-positive strains isolated from the hospital environment. The
thermal analyses have evidenced the thermal intervals of stability and also the thermodynamic effects that accompany them.
After water elimination, complexes have a similar thermal behaviour. Processes as water elimination, melting, chloride anion
removal as well as oxidative degradation of the organic ligands were observed. The final product of decomposition was copper
(II) oxide. 相似文献
3.
Mohammad Akbar Ali Ai Ling Tan Aminul Huq Mirza Jose H. Santos Aimi Hanisah Bte Hj Abdullah 《Transition Metal Chemistry》2012,37(7):651-659
Four tridentate ONS ligands, namely 2-hydroxyacetophenonethiosemicarbazone (H2L1), the 2-hydroxyacetophenone Schiff base of S-methyldithiocarbazate (H2L2), the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-methyldithiocarbazate (H2L3), and the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-benzyldithiocarbazate (H2L4), and their complexes of general formula [Ni(HL1)2], [ML] (M?=?NiII or CuII; L?=?L1, L2, L3 and L4), [Co(HL)(L); L?=?L1, L2, L3 and L4] and [ML(B)] (M?=?NiII or CuII; L?=?L2 and L4; B?=?py, PPh3) have been prepared and characterized by physico-chemical techniques. Spectroscopic evidence indicates that the Schiff bases behave as ONS tridentate chelating agents. X-ray crystallographic structure determination of [NiL2(PPh3)] and [CuL4(py)] indicates that these complexes have an approximately square-planar structure with the Schiff bases acting as dinegatively charged ONS tridentate ligands coordinating via the phenoxide oxygen, azomethine nitrogen and thiolate sulfur atoms. The electrochemical properties of the complexes have been studied by cyclic voltammetry. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(18):3265-3272
Three new centrosymmetric dinuclear copper(II) complexes, [Cu2Cl2(L1)2] (1), [Cu2(μ 1,3-NCS)2(L2)2] (2), and [Cu2(μ 1,1-N3)2(L3)2] (3), where L1, L2, and L3 are the deprotonated forms of the Schiff bases 1-[(2-propylaminoethylimino)methyl]naphthalen-2-ol (HL1), 1-[(3-methylaminopropylimino)methyl]naphthalen-2-ol (HL2), and 2-[(2-isopropylaminoethylimino)methyl]phenol (HL3), respectively, have been prepared and characterized by elemental analysis, IR spectra, and single-crystal X-ray crystallography. Each Cu is coordinated by the three donors of the Schiff bases and by two bridging groups, forming a square-pyramidal geometry. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(19):3217-3231
Two new hexadentate N2O4 donor Schiff bases, H4L1 and H4L2, were synthesized by condensation of 4,6-diacetylresorcinol with glycine and alanine, respectively. The structures of the ligands were elucidated by elemental analyses, IR, 1H NMR, electronic, and mass spectra. Reactions of the Schiff bases with copper(II), nickel(II), and iron(III) nitrates in 1 : 2 molar ratio gave binuclear metal complexes and, in the presence of 8-hydroxyquinoline (8-HQ) or 1,10-phenanthroline (Phen) as secondary ligands (L′), mixed-ligand complexes in two molar ratios 1 : 2 : 2 and 1 : 2 : 1 (L1/L2 : M : L′). The complexes were characterized by elemental and thermal analyses, IR, electronic, mass, and ESR spectral studies, as well as conductivity and magnetic susceptibility measurements. The spectroscopic data reveal that the Schiff-base ligands were dibasic or tetrabasic hexadentate ligands. The coordination sites with the metal ions are two azomethine nitrogens, two oxygens of phenolic groups, and two oxygens of carboxylic groups. Copper(II) complexes were octahedral and square planar while nickel(II) and iron(III) complexes were octahedral. The Schiff bases, H4L1 and H4L2, and some of their metal complexes showed antibacterial activity towards Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and Gram-negative (Pseudomonas fluorescens and Pseudomonas phaseolicola) bacteria and antifungal activity towards the fungi Fusarium oxysporium and Aspergillus fumigatus. 相似文献
6.
Alasdair J. RobbieAndrew R. Cowley Michael W. Jones Jonathan R. Dilworth 《Polyhedron》2011,30(11):1849-1856
Two new sterically demanding diaminophosphinothiolate ligands (HL1 and HL2) have been prepared and the X-ray crystal structure of the Li salt of HL2 has been determined. The complex [Pd(L1)2] was fully characterized, but in contrast to other phosphinothiolates, complexes with the M(L)3 stoichiometry could not be prepared. Reaction of LH1 with Ni(II) led to cleavage of the arythiolate group and isolation of a thiolate bridged dimer, confirmed by an X-ray crystal structure. The Rh(I) complexes [Rh(nbd)L] (L = L1, L2) were characterized including an X-ray structure. 相似文献
7.
Summary Copper(II), nickel(II) and cobalt(II) perchlorate complexes of 5,5-dimethylcyclohexane-1,2,3-trione-2-(p-nitrophenyl-hydrazone) (HL1), 5,5-dimethyl-cyclohexane-1,2,3-trione-2-(p-chlorophenylhydrazone) (HL2), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-chlorophenylhydrazone) (HL4), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-methylphenyl-hydrazone) (HL5) and 5,5-dimethylcyclohexane-1,2,3-trione-2-(m-methylphenylhydrazone) (HL6) have been prepared, and characterized using analytical, spectral and magnetic measurements. The data reveal that the reaction of Cu(ClO4)2 (1 mol) in EtOH, with all ligands, produces complexes of the type CuL(ClO4)(H2O).nH2O. Nickel(II) and cobalt(II) perchlorates react only with HL1 and HL2 to produce the complexes ML(ClO4)(H2O)3 (where M = NiII, L = L– and L2, M = CoII, L = L1) and Co(HL2)2-(ClO4)2.2H2O. The spectral data show that the ligands behave as monobasic bidentate in their azo forms, except HL2 which reacts with cobalt(II) as a neutral bidentate ligand in its hydrazone form. 相似文献
8.
Rodica Olar Mihaela Badea Dana Marinescu Veronica Lazar Carmen Chifiriuc 《Journal of Thermal Analysis and Calorimetry》2009,97(1):315-321
The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of type [NiLCl2]·mH2O ((1) L:L1, m=6; (3) L:L2, m=4) or [CuLCl]nCl
n
·mnH2O ((2) L:L1, m=6; (4) L:L2, m=4) are presented. The ligands L(1) and L(2) have been synthesised by template condensation of 3,6-diazaoctane-1,8-diamine
or 1,2-diaminoethane with formaldehyde and 2-amino-4H-1,2,4-triazole. The bonding and stereochemistry of the complexes have
been characterised by IR, electronic and magnetic studies at room temperature. The in vitro qualitative and quantitative antimicrobial
activity assays showed that the complexes exhibited variable antimicrobial activity against planktonic as well as biofilm
embedded Gram-negative, Gram-positive and fungal strains. The thermal behaviour provided confirmation of the complexes composition
as well as the number and nature of water molecules and the intervals of thermal stability. 相似文献
9.
Wen-Kui Dong Gang Wang Shang-Sheng Gong Jun-Feng Tong Yin-Xia Sun Xiong-Hou Gao 《Transition Metal Chemistry》2012,37(3):271-277
Two new Cu(II) complexes, [Cu(L1)2] (1) and [Cu(L2)2] (2) (HL1 = (E)-3-bromo-5-chloro-2-hydroxy benzaldehyde O-methyl oxime; HL2 = (E)-3-bromo-5-chloro-2-hydroxy benzaldehyde O-ethyl oxime), have been synthesized and characterized by physicochemical and spectroscopic methods. X-ray crystallographic
analyses show that complexes 1 and 2 have similar structures, consisting of one Cu(II) atom and two L− units. In both complexes, the Cu(II) atom, lying on an inversion center, is four-coordinated in a trans-CuN2O2 square-planar geometry by two phenolate O and two oxime N atoms from two symmetry-related N,O-bidentate oxime ligands. Moreover,
both complexes form an infinite three-dimensional supramolecular structure involving intermolecular C–H···Br hydrogen bonds
and π···π stacking interactions between the metal chelate rings and aromatic rings. Substituent effects in the two complexes
are discussed. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(2):339-352
Four new nickel(II), zinc(II), and cobalt(II) complexes, [Zn(L1)2]?·?H2O (1), [Ni(L1)2]?·?H2O (2), [Ni(L2)2] (3), and [Co(L3)2]?·?H2O (4), derived from hydroxy-rich Schiff bases 2-{[1-(5-chloro-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL1), 2-{[1-(2-hydroxy-3-methoxyphenyl)methylidene]amino}-2-ethylpropane-1,3-diol (HL2), and 2-{[1-(5-bromo-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL3) have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray determination. Each metal in the complexes is six-coordinate in a distorted octahedral coordination. The Schiff bases coordinate to the metal atoms through the imino N, phenolate O, and one hydroxyl O. In the crystal structures of HL1 and the complexes, molecules are linked through intermolecular O–H···O hydrogen bonds, forming 1-D chains. The urease inhibitory activities of the compounds were evaluated and molecular docking study of the compounds with the Helicobacter pylori urease was performed. 相似文献
11.
Mehmet Tümer Nihal Deligönül Ayşegül Gölcü Eyüp Akgün Mustafa Dolaz Havva Demirelli Metin Dığrak 《Transition Metal Chemistry》2006,31(1):1-12
Schiff base ligands HL1–HL6 have been prepared from the reaction of 2,6-diformyl-4-t-butylphenol and 2,6-di-formyl-4-methylphenol with various aromatic amines in ethanolic solution. The Schiff base ligands
2,2′-dipyridine (dp) mixed-ligand CuII complexes have been obtained. Mixed-ligand CuII complexes containing the dp ligand have ionic nature and they conduct the electricity in solution media. The complexes have
been obtained in two different forms: one of them is [Cu2(Ln)Cl3] (n: 1, 2, 3, 4, 5 and 6) and other complexes have the general formula [Cu2(Ln)(dp)2]3Cl. Ligands and their complexes have been characterized by elemental analyses, FT-IR, electronic spectra, molar conductance,
1H(13C)-n.m.r. and mass spectral data. Their stoichiometric protonation constants have been determined potentiometrically in dioxan
using a combined pH electrode at 25 °C, under a nitrogen atmosphere. For the calculation of the protonation constants, PKAS
computer programme has been used. The effects of the substituents on the protonation constants and the additivities of these
effects are discussed. The antimicrobial activity studies of the ligands and their complexes have been studied against the
Bacillus megaterium, Micrococcus luteus, Corynebavterium xenosis, Enterococcuc faecalis, bacteria and Saccoramyces cerevisia, yeast. The catalytic properties of the complexes have been studied on the ascorbic acid, catechol and 2,6-di-t-butylphenol substrates. Thermal behaviour of the complexes has been studied by thermal techniques. 相似文献
12.
Some new lead(II) complexes of the general formula Pb(L)2, where HL = Schiff bases derived from the condensation of isatin and chloroisatin with phenylalanine (HL1/HL4), isoleucine (HL2/HL5), and glycine (HL3/HL6), have been synthesized and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H and 13C) studies. In all cases, the Pb atom is in a four-coordinated environment with two bidentate deprotonated Schiff bases binding as monoanionic ligands through the oxygen and azomethine nitrogen. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out for one of the representative compounds, [Pb(L3)2] to substantiate the proposed structures. 相似文献
13.
Petrović A. F. Petrović D. M. Leovac V. M. Budimir M. 《Journal of Thermal Analysis and Calorimetry》1999,58(3):589-596
The paper describes the results of differential thermal analysis of the octahedral Fe(III) complexes of the general formula [Fe(HLn)2]Cl and Fe(HL3)L3, as well as of the corresponding ligands H2Ln (H2Ln — tridentate salicylaldehyde semi thiosemi- and S-methylisothiosemi-carabazones with n=1, 2 and 3 respectively). The decomposition of the complexes involving sulphur-containing ligands (H2L2 and H2L3) starts with sulphur elimination. In case of the complexes [Fe(HL2)]Cl and [Fe(HL3)]Cl sulphur evolves independently, whereas with Fe(HL3)L3 it is eliminated within the SCH3 group. In the former case, sulphur elimination takes place at the same temperature for both complexes. The change in the coordination mode, being a consequence of the replacement of O by S, has no essential effect on thermal stability of the coordination polyhedron. The complexes involving ONN coordination, realized with the H2L3 ligand, exhibit a comparatively highest thermal stability of the coordination polyhedron.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
14.
Aurkie Ray Sambuddha Banerjee Georgina M. Rosair Volker Gramlich Samiran Mitra 《Structural chemistry》2008,19(3):459-465
A nickel(II) and a cobalt(III) complex of two different potentially tetradentate Schiff bases with different binding modes
have been synthesised. The nickel(II) complex [NiL1] · CH3OH (1) was formed, on reacting the metal salt with a perfectly symmetrical N2O2 tetradentate Schiff base ligand H
2
L
1
, which is the 1:2 condensation product of 1,3-diamino propane and 2-hydroxyacetophenone. The cobalt(III) complex [Co(HL2)3] · (ClO4)3 · H2O (2) was synthesised using an asymmetric N2O2 tetradentate Schiff base ligand HL
2
on condensing N,N-dimethyl-1,3-diamino propane with o-vanillin in 1:1 mmol ratio. Although both Schiff bases are N2O2 functionalised, they showed variation in their coordinative property with nickel(II) and cobalt(III) ions. Both the complexes
were characterised by IR spectroscopy and cyclic voltammetry and their single crystal structures clearly indicate that 1 is a mononuclear species whereas 2 is a hydrogen-bonded dimer. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(15):2645-2656
Schiff bases o-vanilidene-1-aminobenzene (HL1) and o-vanilidene-2-methyl-1-aminobenzene (HL2) lead to the formation of mono- and bis-[(Cl)Zn(L1)] (1), [(Cl)Zn(L2)] (2), [(Cl)Hg(L1)] (3), [(Cl)Hg(L2)] (4), [Zn(L1)2] (5), [Zn(L2)2] (6), [Hg(L1)2] (7), and [Hg(L2)2] (8) complexes by reactions of zinc(II) and mercury(II) chlorides in different mole ratio(s). Complexes 1–8 have been characterized by elemental analyses (Zn, Hg, C, H, Cl, and N), melting point and spectral (IR, 1H-NMR), PXRD, molar conductivity measurement, and TGA. Conductivity measurements suggest non-electrolytes. Structural compositions have been assigned by mass spectral studies. Four-coordinate geometry may be assigned to these complexes tentatively. Structural study reveals that in 1–4 two metal centers are held together by two bridged (μ2-Cl) chlorides, whereas 5–8 contain two bidentate Schiff-base ligands around one metal-producing monomers. 相似文献
16.
Synthesis of four different types of ligands Ar[COC(NOH)R]
n
(Ar = biphenyl, n = 1, HL1; Ar = biphenyl, n = 2, H2L2; Ar = diphenylmethane, n = 1, HL3; Ar = diphenylmethane, n = 2, H2L4; R = furfurylamine in all ligands) and their dinuclear Co2+, Ni2+, Cu2+, and Zn2+ complexes is reported herein. These compounds were characterized by elemental analysis, ICP-OES, FT-IR spectra, and magnetic
susceptibility measurements. The ligands were further characterized by 1H NMR. The results suggest that dinuclear complexes of HL1 and HL3 have a metal to ligand mole ratio of 2: 2 and dinuclear complexes H2L2 and H2L4 have a metal to ligand mole ratio of 2: 1. Square pyramidal or octahedral structures are proposed for complexes of oxime
ligands. Furthermore, extraction abilities of the four ligands were also evaluated in chloroform using selected transition
metal picrates such as Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+. The ligands show strong binding ability towards Hg2+ and Cu2+ ions. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(2):352-362
By condensation of rimantadine and substituted salicylaldehyde, three new Schiff bases, HL1, HL2 and HL3, were synthesized. Then, a mixture of one of the new ligands and cobalt(II) chloride hexahydrate in ethanol led to 1, 2, and 3, respectively. These complexes were characterized by melting point, elemental analysis, infrared spectra, molar conductance, thermal analysis, and single-crystal X-ray diffraction analysis. X-ray diffraction analysis reveals that 1 crystallizes in the orthorhombic system, Pbcn space group; each asymmetric unit consists of one cobalt(II) ion, two deprotonated ligands, and one lattice water. The central cobalt is four coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry. Complexes 2 and 3 crystallize in the monoclinic system, P21/c space group; each asymmetric unit consists of one cobalt(II), two corresponding deprotonated ligands, one lattice water, and one methanol. The central cobalt is also four-coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry. 相似文献
18.
Co(II), Ni(II), Cu(II) and Zn(II) complexes of aminothiazole‐derived Schiff base ligands: Synthesis,characterization, antibacterial and cytotoxicity evaluation,bovine serum albumin binding and density functional theory studies
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Transition metal complexes of type M(L)2(H2O)x were synthesized, where L is deprotonated Schiff base 2,4‐dihalo‐6‐(substituted thiazol‐2‐ylimino)methylphenol derived from the condensation of aminothiazole or its derivatives with 2‐hydroxy‐3‐halobenzaldehyde and M = Co2+, Ni2+, Cu2+ and Zn2+ (x = 0 for Cu2+ and Zn2+; x = 2 for Co2+ and Ni2+). The synthesized Schiff bases and their metal complexes were thoroughly characterized using infrared, 1H NMR, electronic and electron paramagnetic resonance spectroscopies, elemental analysis, molar conductance and magnetic susceptibility measurements, thermogravimetric analysis and scanning electron microscopy. The results reveal that the bidentate ligands form complexes having octahedral geometry around Co2+ and Ni2+ metal ions while the geometry around Cu2+ and Zn2+ metal ions is four‐coordinated. The geometries of newly synthesized Schiff bases and their metal complexes were fully optimized in Gaussian 09 using 6–31 + g(d,p) basis set. Fluorescence quenching data reveal that Zn(II) and Cu(II) complexes bind more strongly to bovine serum albumin in comparison to Co(II) and Ni(II) complexes. The ligands and their complexes were evaluated for in vitro antibacterial activity against Escherichia coli ATCC 25922 (Gram negative) and Staphylococcus aureus ATCC 29213 (Gram positive) and cytotoxicity against lever hepatocellular cell line HepG2. 相似文献
19.
Shyamapada Shit Joy Chakraborty Brajagopal Samanta Alexandra M. Z. Slawin Volker Gramlich Samiran Mitra 《Structural chemistry》2009,20(4):633-642
Three new coordination complexes, 2{[Co(L1)2]ClO4} · 0.5CH3OH (1), [Mn(L2)2] (2), and [Cu(HL2)(L2)]ClO4 · 2H2O (3) have been synthesized from two tridentate N,N,O-donor hydrazone ligands HL1, 2-acetylpyridine-salicyloylhydrazone, and HL2, 2-benzoylpyridine-salicyloylhydrazone, respectively and thoroughly characterized by elemental analysis, FT-IR, UV–Vis, electrochemical,
and room temperature magnetic susceptibility measurements. Structures of the complexes have been unequivocally established
by single crystal X-ray diffraction technique. Structural analysis reveals that 1 consists of two chemically similar but crystallographically independent cationic [Co(L1)2]+ units and 2 consists of a neutral [Mn(L2)2] molecule while 3 consists of a cationic [Cu(HL2)(L2)]+ unit. Metal ions display distorted octahedral geometry in 1 and 2 while in 3 it shows a distorted square pyramidal geometry. Ligand conformations around the metal ions are stabilized by the presence
of intra-ligand hydrogen bonding in all the complexes. Structure of 3 reveals that a perchlorate ion linked to the complex by hydrogen bonding via a water molecule. 相似文献
20.
Two new reduced Schiff base ligands, [HL1 = 4-{2-[(pyridin-2-ylmethyl)-amino]-ethylimino}-pentan-2-one and HL2 = 4-[2-(1-pyridin-2-yl-ethylamino)-ethylimino]-pentan-2-one] have been prepared by reduction of the corresponding tetradentate unsymmetrical Schiff bases derived from 1:1: 1 condensation of 1,2-ethanediamine, acetylacetone and pyridine-2-carboxaldehyde/2-acetyl pyridine. Four complexes, [Ni(L1)]ClO4 (1), [Cu(L1)]ClO4 (2), [Ni(L2)]ClO4 (3), and [Cu(L2)]ClO4 (4) with these two reduced Schiff base ligands have been synthesized and structurally characterized by X-ray crystallography. The mono-negative ligands L1 and L2 are chelated in all four complexes through the four donor atoms to form square planar nickel(II) and copper(II) complexes. Structures of 3 and 4 reveal that enantiomeric pairs are crystallized together with opposite chirality in the nitrogen and carbon atoms. The two CuII complexes (2 and 4) exhibit both irreversible reductive (CuII/CuI; Epc, −1.00 and −1.04 V) and oxidative (CuII/CuIII; Epa, +1.22 and +1.17 V, respectively) responses in cyclic voltammetry. The electrochemically generated CuI species for both the complexes are unstable and undergo disproportionation. 相似文献