The synthesis,characterization, electrochemical character,catalytic and antimicrobial activity of novel,azo-containing Schiff bases and their metal complexes

Three novel Schiff base ligands containing the azo group, 2-((E)-(4-((E)-phenyldiazenyl)phenylimino)methyl)phenol, 3-((E)-(4-((E)-phenyldiazenyl)phenylimino)methyl)benzene-1,2-diol and 4-((E)-(4-((E)-phenyldiazenyl)phenylimino)methyl)benzene-1,2,3-triol, were synthesized from the reaction of p-aminoazobenzene with salicylaldehyde, 2,4-dihydroxybenzaldehyde and 2,3,4-trihydroxybenzaldehyde, respectively. The mononuclear Co(II) and Cu(II) complexes of the Schiff base ligands were prepared and characterized using elemental analyses, IR, UV–visible spectroscopy, magnetic susceptibility and conductance measurements; ¹H NMR and mass spectra of the ligands were also recorded. The Co(II) and Cu(II) metal complexes are formed by the coordination of the N and O atoms of the ligands. The electrochemical properties of the metal complexes were investigated at 100 mV s^?1 scan rate in DMSO; the oxidative C–C coupling properties of the Co(II) and Cu(II) complexes were investigated on the sterically hindered 2,6-di-tert-butylphenol (DTBP). In addition, the Schiff base ligands and their complexes were evaluated for both their in vitro antibacterial activity using the disc diffusion method.     

Efficient Allylic Oxidation of Olefins Catalyzed by Polymer Supported Metal Schiff Base Complexes with Peroxides

Three homogeneous Cu(II), Co(II) and Ni(II) complexes of a Schiff base ligand and their heterogeneous complexes supported on poly(4-aminostyrene) were prepared and characterized by using elemental analysis, fourier transform infrared spectroscopy, UV–Vis diffuse reflectance spectroscopy, thermogravimetric analysis and scanning electron microscopy. The catalytic performance of both homogeneous and heterogeneous complexes was evaluated in the liquid phase oxidation of cyclohexene, styrene and trans-stilbene in acetonitrile with tert-butylhydroperoxide or hydrogen peroxide as the oxidant. All types of catalyst were active in oxidation; and, the complexes produce allylic oxidation products in all cases. Immobilized complexes are slightly more active than their homogeneous complexes. The polymer-supported Cu(II) complex shows a higher catalytic activity than the other metal species. The activities of the immobilized catalysts remained nearly the same after five cycles, suggesting the true heterogeneous nature of the catalyst.     

Polymetallic complexes. part iii. schiff base complexes of cobalt(ii), copper(ii), cadmium(ii) and mercury(ii)

Eight polymetallic complexes have been synthesised of the composition M₂L₂._nB [M = Co(II), n = 4, B=H₂O, M = Cu(II), Cd(II) and Hg(II), n = 0] M₂L_2'.nB [M = Co(II), n = 4, B = H₂O; M = Cu(II), Cd(II) and Hg(II), n = 0], LH₂ = bi-bidentate Schiff base derived from benzoin with m-phenylenediamine; L'Hz = tridentate Schiff base derived from benzoin with o-aminophenol. Elemental analysis, conductance, magnetic susceptibility, i.r. and electronic spectral measurements have been done to characterise the complex compounds. A dinuclear octahedral configuration has been assigned to the cobalt(II) complexes and a dinuclear square planar structure to the copper(II) complexes. A tetrahedral configuration has been attributed to the cadmiurn(II) and mercury(II) complexes.     

Novel N,N‐Bidentate Ligands for Enantioselective Copper(I)‐ Catalyzed Allylic Oxidation of Cyclic Olefins

New N,N‐bidentate Schiff base ligands containing the 2‐quinolyl moiety proved to be effective in conferring high reactivity and moderate to high enantioselectivity (up to 84% ee) to the copper(I)‐catalyzed asymmetric allylic oxidation of various cylic olefins with tert‐butyl perbenzoate. As copper(I) sources, we employed copper(II) triflate/phenylhydrazine [Cu(OTf)₂/PhNHNH₂] and tetra(acetonitrile)copper hexafluorophosphate [Cu(CH₃CN)₄PF₆]. Using the same N,N‐bidentate Schiff base ligand, the former showed high reactivity and the latter showed high enantioselectivity.     

Synthesis of polymer-supported metal-ion complexes and evaluation of their catalytic activities

Polymer-supported transition-metal-ion complexes of the N,N′-bis(o-hydroxy acetophenone) propylenediamine (HPPn) Schiff base were prepared by the complexation of iron(III), cobalt(II), and nickel(II) ions on a polymer-anchored N,N′-bis(5-amino-o-hydroxy acetophenone) propylenediamine Schiff base. The complexation of iron(III), cobalt(II), and nickel(II) ions on the polymer-anchored HPPn Schiff base was 83.44, 82.92, and 89.58 wt%, respectively, whereas the unsupported HPPn Schiff base showed 82.29, 81.18, and 87.29 wt % complexation of these metal ions. The iron(III) ion complexes of the HPPn Schiff base showed octahedral geometry, whereas the cobalt(II) and nickel(II) ion complexes were square planar in shape, as suggested by spectral and magnetic measurements. The thermal stability of the HPPn Schiff base increased with the complexation of metal ions, as evidenced by thermogravimetric analysis. The HPPn Schiff base showed a weight loss of 51.0 wt % at 500°C, but its iron(III), cobalt(II), and nickel(II) ion complexes showed weight losses of 27.0, 35.0, and 44.7 wt % at the same temperature. The catalytic activity of the unsupported and supported metal-ion complexes was analyzed by the study of the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The supported HPPn Schiff base complexes of iron(III) ions showed a 73.0 wt % maximum conversion of phenol and 90.6 wt % epoxidation of cyclohexene, but unsupported complexes of iron(III) ions showed 63.8 wt % conversion of phenol and 83.2 wt % epoxidation of cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 wt % and 98.1 wt % with the supported HPPn Schiff base complexes of iron(III) ions, but it was low with the supported Schiff base complexes of cobalt(II) and nickel(II) ions. The selectivity for CTL and ECH varied with the molar ratio of the metal ions but remained unaffected by the molar ratio of hydrogen peroxide to the substrate. The energy of activation for the epoxidation of cyclohexene and oxidation of phenol with the polymer-supported Schiff base complexes of iron(III) ions was 10.0 and 12.7 kJ/mol, respectively, but it was found to be higher with the supported HPPn Schiff base complexes of cobalt(II) and nickel(II) ions and with the unsupported HPPn Schiff base complexes of iron(III), cobalt(II), and nickel(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Removal of Copper(II) from a Concentrated Sulphate Medium by Cloud Point Extraction Using an N,N′-Bis(salicylaldehyde)Ethylenediimine Di-Schiff Base Chelating Ligand

Various chelating ligands have been investigated for the cloud point extraction of several metal ions. However, limited studies on the use of the Schiff base ligands have been reported. In this work, cloud point extraction behavior of copper(II) with N,N′‐bis(salicylaldehyde)Ethylenediimine Schiff base chelating ligand, (H₂SALEN), was investigated in aqueous concentrated sulphate medium. The extraction process used is based on the formation of hydrophobic H₂SALEN–copper(II) complexes that are solubilized in the micellar phase of a non‐ionic surfactant, i.e. ethoxylated (9.5EO) tert‐butylphenol. The copper(II) complexes are then extracted into the surfactant‐rich phase above cloud point temperature. Different parameters affecting the extraction process of Cu(II), such as equilibrium pH, extractant concentration, and non‐ionic surfactant concentration were explored. The extraction of Cu(II) was studied in the pH range of 2–11. The results obtained showed that it was profoundly influenced by the pH of the aqueous medium. The concentration factor, C_f, of about 17 with extraction efficiency of E % ≈100 was achieved. The stoichiometry of the extracted complex of copper(II) was ascertained by the Yoe–Jones method to give a composition of 1:1 (Cu:H₂L). The optimum conditions of the extraction‐removal have been established as the following: (1) 1.86 × 10^?3 mol/L ligand; (2) 3 wt% surfactant; (3) pH of 8 (4) 0.5 mol/L Na₂SO₄ and (5) temperature of 60 °C.     

Synthesis and Characterization of Thermally Stable and Biologically Active Metal-Based Schiff Base Polymer

Schiff base was prepared via condensation of ethanedihydrazide with 2-hydroxy benzaldehyde and further this monomeric Schiff base polymerize with formaldehyde and barbituric acid and form polymeric Schiff base (PLSB) ligand. The ligand and its polymer metal complexes were characterized by using elemental analysis, IR, UV–VIS, ¹HNMR, magnetic susceptibility and thermogravimetric studies. On basis of elemental analysis and spectral studies, six coordinated geometry was assigned for Mn(II), Co(II) and Ni(II) complexes and four coordinated for Cu(II) and Zn(II) complexes. PLSB act as a tetradentate and coordinate through the azomethine nitrogen and phenolic oxygen. The thermal behavior of these polymer metal complexes showed that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The (PLSB) ligands and its polymer metal complexes were screened against bacterial species Escherichia coli, Staphylococcus aureus, Bacillus subtilis and fungal species Aspergillus flavus, Candida albicans, A. niger. The activity data show that the metal complexes were more potent than the parent Schiff bases.     

Highly selective oxidation of alcohols catalyzed by Cu(II)-Schiff base-SBA-15 with hydrogen peroxide in water

An efficient catalyst for selective oxidation of alcohols was prepared by grafting the Cu(II) Schiff base complex onto the channels of mesoporous silica material SBA-15. The characterizations illustrated that the functionalized SBA-15 maintained the primary hexagonally ordered mesoporous structure, and the Cu(II) Schiff base complexes were bonded inside the mesoporous channels of SBA-15. The selective oxidation of benzyl alcohol was carried out in water phase with hydrogen peroxide. The C₆H₅CH₂OH conversion could reach 98.5 % with 100 % of the selectivity to C₆H₅CHO under the optimum conditions. The catalyst could also react well on the selective oxidation of other primary alcohols.     

New antimicrobial agents: The synthesis of Schiff base polymers containing transition metals and their characterization and applications

A new polymeric Schiff base containing formaldehyde and 2‐thiobarbituric acid moieties was synthesized by the condensation of a monomeric Schiff base derived from 2‐hydroxyacetophenone and hydrazine. Polymer–metal complexes were also synthesized by the reaction of the polymeric Schiff base with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) acetate. The polymeric Schiff base and its polymer–metal complexes were characterized with magnetic moment measurements, elemental analyses, and spectral techniques (infrared, ¹H‐NMR, and ultraviolet–visible). The thermal behaviors of these coordination polymers were studied by thermogravimetric analysis in a nitrogen atmosphere up to 800°C. The thermal data revealed that all of the polymer–metal complexes showed higher thermal stabilities than the polymeric Schiff base and also ascribed that the Cu(II) polymer–metal complex showed better heat resistant properties than the other polymer–metal complexes. The antimicrobial activity was screened with the agar well diffusion method against various selected microorganisms, and all of the polymer–metal complexes showed good antimicrobial activity. Among all of the complexes, the antimicrobial activity of the Cu(II) polymer–metal complex showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Host (nanocavity of zeolite-Y)/guest (Mn(II), Co(II), Ni(II) and Cu(II) complexes of pentadendate Schiff-base ligand) nanocomposite materials (HGNM): application in the heterogeneous oxidation of cyclohexene

Transition metal (M = Mn(II), Co(II), Ni(II) and Cu(II)) complexes with pentadendate Schiff-base ligand; N,N′-bis(salicylidene)-2,6-pyridinediaminato, H₂ [sal-2,6-py]; was entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of bis(salicylaldiminato)metal(II); [M(sal)₂]-NaY; in the supercages of the zeolite, and (ii) in situ Schiff condensation of the metal(II) precursor complex with the corresponding 2,6-pyridinediamine; [M(sal-2,6-py)]-NaY. The new materials were characterised by several techniques: chemical analysis, spectroscopic methods (DRS, BET, FTIR and UV/Vis), conductometric and magnetic measurements. Analysis of the data indicates that the M(II) complexes are encapsulated in the nanodimensional pores of zeolite-Y and exhibit different from those of the free complexes, which can arise from distortions caused by steric effects due to the presence of sodium cations, or from interactions with the zeolite matrix. The Host–Guest Nanocomposite Materials (HGNM); [M(sal-2,6-py)]-NaY; catalyzes the oxidation of cyclohexene with tert-butylhydroperoxide (TBHP). Oxidation of cyclohexene with HGNM gave 2-cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene. [Mn(sal-2,6-py)]-NaY shows significantly higher catalytic activity than other catalysts.     

Homogenous and Heterogeneous Catalytic Activity of Azo-Linked Schiff Base Complexes of Mn(II), Cu(II) and Co(II)

Abstract  

Azo linked Schiff-base[L] complexes of Mn(II)(1), Cu(II)(2) and Co(II)(3) obtained by template method, in the reaction of 4-(benzeneazo) salicylaldehyde with 1,2-propanediamine in the present of metal acetate, respectively. Complexes are used as catalyst for oxidation of cyclohexene with tert-butylhydroperoxide (TBHP); oxidation of cyclohexene catalyzed by these complexes gave 2-cyclohexene-1-one and 2-cyclohexene-1-ol as major products. Conversion of cyclohexene achieved was 95–100% with (1), (2) and (3), with selectivity of 57, 92 and 100% for 2-cyclohexene-1-one, respectively. The encapsulated Cu(II) complex (Cu–NaY) catalyzes the oxidation of cyclohexene using TBHP as oxidant in good yield. (Cu–NaY) under optimized reaction condition gave three reaction products. A maximum of 100% conversion of cyclohexene has been achieved where selectivity of 2-cyclohexene-1-one was 83%.     

New polymeric Schiff base and its metal complexes

A novel polymeric Schiff base was synthesized by the reaction of a Schiff base from 2,4‐dihydroxy benzaldehyde and aniline with acryloyl chloride and was polymerized in methyl ethyl ketone at 70°C with benzoyl peroxide as a free‐radical initiator. Polychelates were obtained in an alkaline solution of poly(2‐hydroxy‐4‐acryloyloxy‐N‐phenylbenzylidine) with aqueous solutions of metal ions such as Cu(II), Ni(II), Co(II), Ca(II), Cd(II), Mn(II), and Zn(II). The polymeric Schiff base and polychelates were characterized with elemental analysis and spectral studies. The elemental analysis of the polychelates suggested that the metal‐to‐ligand ratio was 1:2. The IR spectral data of the polychelates indicated that the metals were coordinated through the nitrogen and oxygen of the phenolic ? OH group. Diffuse reflectance spectra, electron paramagnetic resonance, and magnetic moment studies revealed that the polychelates of the Cu(II) complex were square‐planar, those of the Ni(II), Mn(II), and Co(II) complexes were octahedral, and those of the Ca(II), Cd(II), and Zn(II) complexes were tetrahedral. X‐ray diffraction studies revealed that the polychelates were highly crystalline. The thermal properties of the Schiff base and polychelates were also examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 494–500, 2004     

Electron-rich salen-type Schiff base complexes of Cu(II) as catalysts for oxidation of cyclooctene and styrene with tert-butylhydroperoxide: A comparison with electron-deficient ones

Two square planar copper(II) complexes of tetradentate Schiff base ligands derived from aromatic aldehydes and 2,2′-dimethylpropandiamine (H₂{salnptn(3-OMe)₂}, H₂{hnaphnptn}) have been prepared and used as catalysts for oxidation of cyclooctene and styrene with tert-butylhydroperoxide (TBHP). Oxidation of cyclooctene with TBHP gave cyclooctene oxide as the sole product, but in the case of styrene a mixture of styrene oxide and benzaldehyde has been obtained in ca. 1:3 molar ratio. It has been shown that the rate and selectivity of reaction depend to the electron-donor ability of substituents at the phenyl groups of the ligand and can be improved by introduction of π-electron-donating groups at the aromatic rings of salen-type Schiff bases. The structure of Cu{salnptn(3-OMe)₂} has been determined by X-ray crystallography at 291 K with results generally in agreement with those previously reported. The results suggest that the symmetrical Schiff base ligands are bivalent anions with tetradentate N₂O₂ donors derived from the phenolic oxygen and azomethine nitrogen atoms.     

Cu(II), Co(II) and Ni(II) Complexes Installed on Functionalized Silica Surface for Hydrogen Peroxide Assisted Cyclohexane Oxidation

In this work, Cu(II), Co(II) and Ni(II) complexes of the Schiff base ((S,E)-2-(3,4-dimethoxybenzylideneamino)-3-(1H-imidazol-4-yl)propionic acid) were synthesized and subsequently anchored onto amine functionalized silica. They were characterized by FT-IR, UV–vis., ²⁹Si NMR, TG-DTG, ESR, FE-SEM and AFM techniques, and employed as catalysts in cyclohexane oxidation using hydrogen peroxide oxidant. Silica supported Cu(II) catalyst was shown the highest catalytic activity (70%) than rest of the catalysts used. On the other hand, all the complexes were selective as they yield only cyclohexanol and cyclohexanone. Silica supported catalysts were maintained their catalytic activity over five successive catalytic run. As these catalysts are selective, reusable and functioning well with hydrogen peroxide, they could design the environment friendly catalytic system for effective cyclohexane oxidation.     

The ring‐opening polymerization of D,L‐lactide catalyzed by new complexes of Cu,Zn, Co,and Ni Schiff base derived from salicylidene and L‐aspartic acid

D ,L ‐lactide (LA) was first successfully ring‐opening polymerized in melt by Schiff base complexes K[ML]nH₂O [M = Cu(II), Zn(II), Co(II), Ni(II); n = 2, 2, 3, 3.5; H₃L = L‐aspartic acid‐salicylidene Schiff base], which were prepared by Schiff base ligand derived from salicylidene and L‐aspartic acid and corresponding acetates. The effects of various complexes, the molar ratio of K[ML]nH₂O/LA, the polymerization temperature, and time were studied in detail. The results show that all complexes studied have the ability to initiate the ring‐opening polymerization of D ,L ‐lactide in melt. More than 90% high polymerization conversion and narrow molecular weight distribution (MWD) can be obtained very easily. However, the Ni(II) complex shows better catalytic property than other complexes on the polymerization and the molecular weight (MW) of poly(D ,L ‐lactide) (PLA) produced. With a rise in temperature and a prolongation of time, the MW of PLA decreased remarkably. The MW of PLA prepared by all complexes is not very high, which might be related to the crystalline water of complexes. X‐ray study indicated that PLA produced by Ni(II) complex is an amorphous polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3312–3315, 2002     

Oxovanadium(IV) Schiff base complexes derived from 2,2′-dimethylpropandiamine: A homogeneous catalyst for cyclooctene and styrene oxidation

Tetradentate Schiff base ligands, derived from aromatic aldehydes and aliphatic diamine (2,2′-dimethylpropandiamine), and their vanadyl complexes have been prepared and characterized. Catalytic potential of these complexes was tested for the oxidation of cyclooctene and styrene using tert-butylhydroperoxide (TBHP) as oxidant. The effects of molar ratio of oxidant to substrate, temperature and solvent have been studied. Excellent selectivity of epoxidation for cyclooctene and good selectivity for styrene were obtained. The mechanism of oxidation has also been discussed.     

Polystyrene anchored vanillin Schiff base—Complexation and ion removal studies

A set of six new polystyrene anchored metal complexes have been synthesized by the reaction of the metal salt with the polystyrene anchored Schiff base of vanillin. These complexes were characterized by elemental analyses, Fourier transform infrared spectroscopy, diffuse reflectance studies, thermal studies, and magnetic susceptibility measurements. The elemental analyses suggest a metal : ligand ratio of 1 : 2. The ligand is unidentate and coordinates through the azomethine nitrogen. The Mn(II), Fe(III), Co(II), Ni(II), and Cu(II) complexes are all paramagnetic while Zn(II) is diamagnetic. The Cu(II) complex is assigned a square planar structure, while Zn(II) is assigned a tetrahedral structure and Mn(II), Fe(III), Co(II), and Ni(II) are all assigned octahedral geometry. The thermal analyses were done on the ligand and its complexes to reveal their stability. Further, the application of the Schiff base as a chelating resin in ion removal studies was investigated. The polystyrene anchored Schiff base gave 96% efficiency in the removal of Ni(II) from a 20‐ppm solution in 15 min, without any interference from ions such as Mn(II), Co(II), Fe(III), Cu(II), Zn(II), U(VI), Na⁺, K⁺, NH₄⁺, Ca²⁺, Cl^?, Br^?, NO₃^?, NO₂^?,and CH₃CO₂^?. The major advantage is that the removal is achieved without altering the pH. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1536–1539, 2005     

Synthetic,spectroscopic, magnetic,thermal, and antimicrobial approach towards new biocidal coordination polymers

O‐aminophenol was reacted with glutraldehyde to obtain Schiff base, which was then reacted with formaldehyde in slight acidic medium to generate phenolic groups. Now the substituted Schiff base was reacted with the transition metal acetates of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) to get polymeric metal complexes. Their structures have been elucidated on the basis of elemental analyses, ¹H NMR spectra, ¹³C NMR spectra, magnetic measurements, thermogravimetric analyses, electronic spectra, and infrared spectra. The results are in accordance with an octahedral environment around the central metal ion. The polychelates of Mn(II), Co(II), Ni(II), and Cu(II) are paramagnetic while Zn(II) polychelate was found to be diamagnetic. The synthesized Schiff base acted as a uninegative bidentate ligand and bonding occurs through the hydroxyl oxygen and nitrogen atoms. The thermal behavior of these coordinating polymers was studied by TGA in nitrogen atmosphere up to the temperature range of 800°C. All the synthesized polychelates were also screened for their biocidal activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis (bacteria), Candida albicans, and Muller species (yeast) by using agar well diffusion method. All the metal polychelates show promising antimicrobial activities. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124:3971–3979, 2012     

水杨醛双Schiff碱与其铜配合物的合成与抗菌活性研究

文章首先合成了水杨醛双SchiffN,N’-双（2-水杨醛亚胺基乙基）-2,6-吡啶二甲酰胺（Iia）,并以它为配体合成了铜配合物,通过波谱分析对其结构进行了表征。并采用固体培养基抑菌圈法和液体培养基比浊法对了Schiff碱及其铜配合物进行抗菌活性的测定。结果表明,水杨醛双Schiff碱及其铜配合物对大肠杆菌和金黄色葡萄球菌均有抗菌活性,并且水杨醛双Schiff碱铜配合物的抗菌活性比水杨醛双Schiff碱的抗菌活性强。     

Antimicrobial Polychelates: Synthesis and Characterization of Transition Metal Chelated Barbituric Acid–Formaldehyde Resin

A monomeric Schiff base was prepared by the condensation reaction of salicylaldehyde and semicarbazide, which further react with formaldehyde and barbituric acid-formed polymeric Schiff base. Its metal polychelates were then formed with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). All the synthesized compounds were characterized by elemental analysis, magnetic moment, FTIR, ¹HNMR, and electronic spectroscopies. The elemental analysis data show the formation of 1:1 [M: L] metal polychelates. Thermogravimetric analysis was carried out to find the thermal behavior of all the synthesized polymeric compounds and thermal data revealed that all the metal polychelates are more thermally stable than their parent polymeric Schiff base. All the synthesized polymeric compounds were screened for antimicrobial activity against some clinically important microorganisms, such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus typhi, Candida albicans, Microsporum canis, and Aspergillus niger. In vitro antimicrobial activity was determined by the Agar Well Diffusion method and the result shows that all the metal polychelates exhibited better antimicrobial activity than their parent polymeric Schiff base.