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1.
Schiff bases are the most widely used versatile ligands, able to coordinate many elements and to stabilize them in various oxidation states. Recently, this class of compounds has been employed as models for biological systems, and in control of stereochemistry in six-coordinate transition metal complexes. Recently, the chemistry of organotin(IV) complexes of Schiff bases has also stemmed from their antitumour, antimicrobial, antinematicidal, anti-insecticidal and anti-inflammatory activities. Furthermore, organotin(IV) complexes of Schiff bases present a wide variety of interesting structural possibilities. Both aliphatic and aromatic Schiff bases in their neutral and deprotonated forms have been used to yield adducts and chelates with variable stoichiometry and different modes of coordination. This critical review (>155 references) focuses upon the chemistry and biological applications of organotin(IV) complexes of Schiff bases reported in the past 15 years. Thermal behavior of these complexes is also discussed. 相似文献
2.
Schiff bases, named after Hugo Schiff , are aldehyde‐ or ketone‐like compounds in which the carbonyl group is replaced by imine or azomethine group. They are widely used for industrial purposes and also have a broad range of applications as antioxidants. An overview of antioxidant applications of Schiff bases and their complexes is discussed in this review. A brief history of the synthesis and reactivity of Schiff bases and their complexes is presented. Factors of antioxidants are illustrated and discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
3.
Ranjan K. Mohapatra Pradeep K. Das Manoj K. Pradhan Abdussalam A. Maihub Marei M. El-ajaily 《Journal of the Iranian Chemical Society》2018,15(10):2193-2227
Schiff bases are stable imines containing C=N, where N is bonded to an alkyl or aryl group, but not with hydrogen and are prepared by condensation of aliphatic or aromatic primary amine with carbonyl compounds. They have the general formula R1R2C?=?NR3, where R3?≠?H. The presence of the basic donor N atom and the stability of the imine function render Schiff bases as the most favored ligands that have the ability to stabilize metal ions in different oxidation states. The chelating environment in a Schiff base profoundly influences the electron distribution in the coordination sphere of metal in a complex and thereby regulates the property of the compounds in a big way. The structural diversity in some of the metal complexes with multidentate Schiff base ligands has triggered a wide range of applications of this class of compounds in sensors, catalysis, biology, medicines, and photonics. This review compiles the synthesis and biological activities (antimicrobial, antioxidant, anticancer, antitubercular, DNA interaction studies) of benzaldehyde-based Schiff bases and their metal complexes. 相似文献
4.
Ruthenium complexes bearing bidentate Schiff base ligands as efficient catalysts for organic and polymer syntheses 总被引:1,自引:0,他引:1
Renata Drozdzak Nele Ledoux Valerian Dragutan 《Coordination chemistry reviews》2005,249(24):3055-3074
A concise overview is given on mononuclear and dinuclear, bidentate Schiff base ruthenium complexes with different additional ligands and on their applications in various chemical transformations such as Kharasch addition, enol-ester synthesis, alkyne dimerization, olefin metathesis and atom transfer radical polymerization. These new ruthenium complexes, conveniently prepared from commonly available ruthenium compounds, are very stable, exhibit a good tolerance towards organic functionalities, air and moisture and display high activity and chemoselectivity in chemical transformations. Relevant features of coordination chemistry connected with the reaction mechanism and chemoselectivity are also fully described. Since the nature of Schiff bases can be changed in a variety of ways, appealing routes for designing and preparing novel ruthenium complexes can be foreseen in the future. 相似文献
5.
The most imperative outcomes of extensive sterdies (synthesis, spectral, structural characterization and biological applications) of metal complexes with thiazole derived ligands are reviewed. A large number of coordination compounds are known but still there is a need of new compounds to develop various efforts in different fields for biomedical applications. The synthesis of Schiff base ligands is very important, and it has recently drawn the attention of numerous research groups, making this area constantly evolve. Authors are also synthesizing some novel biologically potent ligands and their unique complexes and complexes found more biological active agents than that of ligands against bacteria, fungi and herbs. Highlights: Schiff bases and their metal chelates catalyze reactions; Schiff bases derived from sulfane thiadiazole show toxicities against insects; Schiff bases of thiadiazole have good plant regulator activity; Phenyl ring attached to the thiazole group showed interesting structure activity. 相似文献
6.
Shazia Parveen 《应用有机金属化学》2020,34(8):e5687
Nowadays in cancer treatment, both metal complexes and organic molecules are being widely used. Current years have seen a surge of interest in the application of organometallic compounds to treat cancer and other diseases. Undeniably, the unique properties of organometallic compounds, intermediate between those of classical inorganic and organic materials, provide new opportunities in the field of medicinal chemistry. Since the discovery of cisplatin, many transition metal complexes have been synthesized and assayed for anticancer activity. In recent years, ruthenium-based Schiff base complexes have emerged as promising antitumor and antimetastatic agents with potential uses in treatment of platinum-resistant tumors or as alternatives to platinum-based chemotherapy. Advantages of utilizing ruthenium complexes in drug development include reliable methods of synthesizing stable complexes; the ability to tune ligand affinities, electron transfer and substitution rates, and reduction potentials; and an increasing knowledge of the biological effects of such complexes. This great expansion of ruthenium-based Schiff base complexes is mainly due to the unique ability of the ruthenium core to permit multiple oxidation states, hence versatile electron-transfer pathways, and because of the ease of preparation with versatile and variable-denticity Schiff base ligands. This review aims to bring the reader up to date with the more recent Ru(II)/(III)-based Schiff base complexes that have been synthesized and investigated for their cytotoxicity. 相似文献
7.
《Journal of Coordination Chemistry》2012,65(24):4367-4379
New nickel(II) and copper(II) complexes with unsymmetrical Schiff bases derived from aromatic 2-hydroxy aldehydes were synthesized and characterized by elemental analyses, melting points, 1H-NMR, magnetic susceptibility, thermogravimetric analysis, differential scanning calorimetry (DSC), infrared (IR), and electronic spectral measurements. Comparison of IR spectra of the Schiff bases and their metal complexes indicated that the Schiff bases are tetradentate, coordinated via the two azomethine nitrogens and the two phenolic oxygens. Magnetic moments and electronic spectral data confirm square-planar geometry for the complexes. Thermal studies reveal a general decomposition pattern, whereby the complexes decomposed partially in a single step due to loss of part of the organic moiety. A single endothermic profile, corresponding to melting point, was observed from the DSC of all complexes, except those whose ligand contained the nitro group, which decomposed exothermally without melting. The Schiff bases and their complexes were screened in vitro against 10 human pathogenic bacteria. The metal(II) complexes exhibited higher antibacterial activity than their corresponding Schiff bases. 相似文献
8.
《Journal of Coordination Chemistry》2012,65(13):2264-2289
Schiff bases are aldehyde or ketone like compounds in which the carbonyl group is replaced by imine or azomethine group. They are widely used for industrial purposes and also exhibit a broad range as extractants. A general view of solvent extraction applications of complexes is discussed in this review. The family of Schiff bases and their extraction of various transition metals such as Co, Cu, Cr, Fe, Ga, Hg, Mn, Mo and Ni are discussed. A brief history of the synthesis and reactivity of Schiff bases will be presented. Factors on solvent extraction will be illustrated and discussed. 相似文献
9.
Chepurnaya I. A. Gaman'kov P. V. Rodyagina T. Yu. Vasil'eva S. V. Timonov A. M. 《Russian Journal of Electrochemistry》2003,39(3):314-317
No polymer compounds form if primary products of electrooxidation Ni and Pd complexes with Schiff bases are octahedral complexes or if the source compounds have a nonplanar structure. This confirms the stack model of the formation of polymer complexes of transition metals with Schiff bases. 相似文献
10.
Kumar KN Ramesh R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(12):2913-2918
Stable ruthenium(II) carbonyl complexes having the general composition [RuCl(CO)(PPh3)(B)(L)] (where B=PPh3, pyridine, piperidine or morpholine; L=anion of bidentate Schiff bases (Vanmet, Vanampy, Vanchx)) were synthesized from the reaction of [RuHCl(CO)(PPh3)2(B)] with bidentate Schiff base ligands derived from condensation of o-vanillin with primary amines such as methylamine, 2-aminopyridine and cyclohexylamine. The new complexes were characterized by elemental analysis, IR, UV-Vis and 1H NMR spectral data. The redox property of the complexes were studied by cyclic voltammetric technique and the stability of the complexes towards oxidation were related to the electron releasing or electron withdrawing ability of the substituent in the phenyl ring of o-vanillin. An octahedral geometry has been assigned for all the complexes. In all the above reactions, the Schiff bases replace one molecule of PPh3 and hydride ion from the starting complexes, which indicate that the Ru-N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru-P. The Schiff bases and their ruthenium(II) complexes have been tested in vitro to evaluate their activity against bacteria, viz., Staphylococcus aureus (209p) and E. coli (ESS 2231). 相似文献
11.
《Journal of Coordination Chemistry》2012,65(24):4398-4410
Cobalt(II) complexes of a new series of unsymmetrical Schiff bases have been synthesized and characterized by their elemental analyses, melting points, magnetic susceptibility, thermogravimetric analysis, differential scanning calorimetry, infrared (IR), and electronic spectral measurements. The purity of the ligands and the metal complexes are confirmed by microanalysis, while the unsymmetrical nature of the ligands was further corroborated by 1H-NMR. Comparison of the IR spectra of the Schiff bases and their metal complexes confirm that the Schiff bases are tetradentate and coordinated via N2O2 chromophore. The magnetic moments and electronic spectral data support square-planar geometry for the cobalt(II) complexes. The complexes were thermally stable to 372.3°C and their thermal decomposition was generally via the partial loss of the organic moiety. The Schiff bases and their complexes were screened for in vitro antibacterial activities against 10 human pathogenic bacteria and their minimum inhibitory concentrations were determined. Both the free ligands and cobalt(II) complexes exhibit antibacterial activities against some strains of the microorganisms, which in a number of cases were comparable with, or higher than, that of chloramphenicol. 相似文献
12.
V. Rakhmanov A. L. Maximov A. V. Tarakanova Fam Vin’ Tkhay A. V. Anisimov 《Moscow University Chemistry Bulletin》2010,65(6):380-383
The electrospray ionization-mass spectrometry (ESI-MS) method has been used for determination of the structure of niobium peroxocomplexes. The formation of mono- and bisperoxocomplexes has been established. These complexes contain Schiff bases and 8-quinolinol as ligands. Trisperoxocomplexes are formed when pyridine and 1,10-phenanthroline are used. Peroxocomplexes with Schiff bases as ligands has shown a high activity as catalysts in the methylphenylsulphide oxidation. 相似文献
13.
The Schiff bases derived from 3,4-dimethyl-Δ3-tetrahydrobenzaldehyde or 4,6-dimethyl-Δ3-tetrahydrobenzaldehyde and glycine and their complexes with nickel (II) and copper (II) were synthesized and investigated.
All compounds were characterized by elemental analyses, conductivity measurements, and FT-IR spectroscopy. The Schiff base
ligands and their complexes were further characterized by 1H NMR. The results suggest that the Schiff base acts as a bidentate ligand, which bonds to the metal ions through the imino
nitrogen and carboxylate oxygen. The potassium salts of the Schiff bases are 1 : 1 electrolytes but all the complexes are
nonelectrolytes.
The article was submitted by the authors in English. 相似文献
14.
In the past decades, the oxidation of hydrocarbons by transition metal complexes has been studied extensively. The current progress of the research on synthetic quasiporphyrin catalysts has led to the development of several systems that are able to reproduce the hene-enzyme mediated oxygenation and oxidation reactions[1]. In our group[2,51, the mononuclear complexes of amino acid Schiff base have been synthesized and their catalytic oxidation has been studied. In this paper, two dinuclear complexes, such as Salicylidence-β-alanine-Co(II)-Cu(II) and Salicylidence-β-alanine-Co(II)Mn(II), were prepared with amino acid Schiff bases and metal ions. In the presence of these dinuclear complexes, cyclohexene was effectively oxidized under 1 atm of molecular oxygen without any coreductants. The allylic hydroperoxide was obtained as an important product, which suggested a clear allylic pathway of oxidation of cyclohexene. 相似文献
15.
Two new Schiff base ligands with chromone moiety and their transition metal complexes were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conductance and TGA analyses, FT IR, UV-Vis, NMR and mass spectroscopy. All the complexes synthesized have been investigated as functional models for catechol oxidase (catecholase) activity by employing 3,5-di-tert-butylcatechol as a model substrate. The two mononuclear copper(II) and two mononuclear iron(II) complexes show catecholase activity with turnover (kcat) numbers lying in the range 27.2–1328.4 h?1. According to the kinetic measurement results, the rate of catechol oxidation follows first order kinetics and iron(II) complexes were found to have higher catalytic activity than those of copper(II) complexes. Electron-donating substituent on Schiff base ligand enhanced the catalytic activity of metal complexes while the electron-withdrawing substituent led to a decrease in activity. The electrochemical properties of two Schiff bases and their metal complexes were also investigated by Cyclic Voltammetry (CV) using glassy carbon electrode (GCE) at various scan rates. Electrochemical processes of all the compounds were observed as irreversible. 相似文献
16.
Edyta Raczuk Barbara Dmochowska Justyna Samaszko-Fiertek Janusz Madaj 《Molecules (Basel, Switzerland)》2022,27(3)
Schiff bases are a vast group of compounds characterized by the presence of a double bond linking carbon and nitrogen atoms, the versatility of which is generated in the many ways to combine a variety of alkyl or aryl substituents. Compounds of this type are both found in nature and synthesized in the laboratory. For years, Schiff bases have been greatly inspiring to many chemists and biochemists. In this article, we attempt to present a new take on this group of compounds, underlining of the importance of various types of Schiff bases. Among the different types of compounds that can be classified as Schiff bases, we chose hydrazides, dihydrazides, hydrazones and mixed derivatives such as hydrazide–hydrazones. For these compounds, we presented the elements of their structure that allow them to be classified as Schiff bases. While hydrazones are typical examples of Schiff bases, including hydrazides among them may be surprising for some. In their case, this is possible due to the amide-iminol tautomerism. The carbon–nitrogen double bond present in the iminol tautomer is a typical element found in Schiff bases. In addition to the characteristics of the structure of these selected derivatives, and sometimes their classification, we presented selected literature items which, in our opinion, represent their importance in various fields well. 相似文献
17.
Vinusha H. Mariwamy Shiva Prasad Kollur Bindya Shivananda Muneera Begum Chandan Shivamallu Chandan Dharmashekara Sushma Pradeep Anisha S. Jain Shashanka K. Prasad Asad Syed Abdallah M. Elgorban Salim Al-Rejaie Joaquín Ortega-Castro Juan Frau Norma Flores-Holguín Daniel Glossman-Mitnik 《Molecules (Basel, Switzerland)》2022,27(4)
18.
UV-vis, IR and (1)H NMR spectroscopic studies of some Schiff bases derivatives of 4-aminoantipyrine 总被引:1,自引:0,他引:1
Issa RM Khedr AM Rizk HF 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,62(1-3):621-629
Five Schiff bases derived from 4-aminoantipyrine and benzaldehyde derivatives (I) are prepared and their UV-vis, IR, (1)H NMR and fluorescence spectra are investigated and discussed. The electronic absorption spectra of the hydroxy 4-aminoantipyrine Schiff bases Ib and Ie as well as the fluorescence spectra of Ie are studied in the organic solvents of different polarity. The UV-vis absorption spectra of 4-aminoantipyrine Schiff bases Ib, Id and Ie are investigated in aqueous buffer solutions of varying pH and utilized for the determination of pK(a) and DeltaG of the ionization process. The reactions of the hydroxy compounds Ib and Ie with Ni(II) and Cu(II) ions are also studied. The results of spectral studies are supported by some molecular orbital calculations using an atom superposition and electron delocalization molecular orbital theory for a compound Ib. 相似文献
19.
Sarma Chandana Chaurasia Pankaj Kumar Bharati Shashi Lata 《Russian Journal of General Chemistry》2019,89(3):517-531
Russian Journal of General Chemistry - Manganese forms a big number of complexes with Schiff bases that are extensively used as catalysts of oxidation, epoxidation, decarboxylation, coupling... 相似文献
20.
Novel series of nonionic Schiff bases was synthesized and characterized using microelemental analysis, FTIR and (1)H NMR spectra. These Schiff bases and their complexes with Cu and Fe have been evaluated for their antibacterial activity against bacterial species such as Staphylococcus aureus, Pseudomonas aureus, Candida albi, Bacillus subtilis and Escherichia coli and their fungicidal activity against Aspcrgillus niger and Aspcrgillus flavus. The results of the biocidal activities showed high potent action of the synthesized Schiff bases towards both bacteria and fungi. Furthermore, complexation of these Schiff bases by Cu(II) and Fe(III) show the metal complexes to be more antibacterial and antifungal than the Schiff bases. The results were correlated to the surface activity and the transition metal type. The mode of action of these complexes was discussed. 相似文献