Investigation of cobalt complexes of Schiff"s bases and dioximes radical precursors and molecular recognition by Robert Ellis (undifferentiated)

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Published by Derbyshire College of Higher Education in [Derby] .

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Thesis (PhD) - Council for National Academic Awards (Great Britain)

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Investigation of cobalt complexes of Schiff's bases and dioximes - radical precursors and molecular recognition. Author: Ellis, Robert. ISNI: Awarding Body: Derbyshire College of Higher Education Current Institution: University of Derby Date of Award. Herein reported Schiff base ligands have been synthesized without isolation, purification or characterisation.

“In situ” prepared ligands have been coordinated with cobalt(II) chloride in the presence of air, which allowed spontaneous oxidation to cobalt(III) complexes ().Complex 3 has already been prepared previously by slightly different procedure.Cited by: We previously reported that the tetraazamacrocyclic Schiff base complex [CoIII(CR14)(X)2]n+ (CR14 = 2,dimethyl-3,7,11,tetraazabicyclo[]heptadeca-1(17),2,11,13,pentaene, X = Cl (n = 1) (1-Cl2) or H2O (n = 3) (1-(H2O)2)) is a very efficient H2-evolving catalyst (HEC) in fully aqueous solutions at pH – when used in a photocatalytic system including a photosensitizer and Cited by: 9.

Abstract A few complexes of cobalt (II) with monovalent tridentate Schiff bases have been prepared and characterised by elemental analysis. The magnetic, electronic and infrared spectral data show that cobalt (II) has coordination number six in these by: 1.

The reactions of nickel(II) and cobalt(II) complexes, [MCl 2(PPh3)2] (M = Ni or Co) with bidentate Schiff base ligands derived from acetylacetone or benzoylacetone with aniline, o- m-nitroaniline.

In the present investigation, the presence of water molecules in the cobalt complexes as indicated in the IR spectra was as certained and verified by the thermal analysis.

The thermal studies indicate that complexes decompose after dehydration. COBALT COMPLEXES WITH BIDENTATE SCHIFF BASES G.R. Pandhare Preparation methods of Schiff base complexes:(Bydirect interaction of the Schiff base with the metal salts) The Schiff base can be synthesized without Investigation of cobalt complexes of Schiffs bases and dioximes book the metal ion and then followed by addition of the metal ion as salt solution for complex formation.

This can be easily described by the following example. Scheme 3. Chromium azomethine complexes 1, cobalt complex Schiff base, un-symmetrical complex chromium, dyes give fast colours to leathers, food packages, wools etc.

Azo groups containing metal complexes, are used for dying cellulose ployester textiles. Some metal complexes are used to mass dye polyfibers. Cobalt complex of a. Forms very stable complexes with transition metals, which are now widely tested in order to detect a potential catalytic and pharmacological activity.

This study involves the synthesis of imines and complexes with biogenic bivalent metals (copper and cobalt. article highlighting the catalytic activity of Schiff base complexes realized7,8. Schiff bases are the compounds containing azimethine group (-HC=N-).

They are condensation products of ketones or aldehydes with primary Investigation of cobalt complexes of Schiffs bases and dioximes book and were first reported by Hugo Schiff in Formation. Metal complexes of Cu(II), Co(II) and Cd(II) have been synthesized using two new Schiff base ligands, N,N'-bis(4-chlorobenzylidene)ethane-1,2-diamine (L 1) and N,N'-bis(3-nitrobenzylidene) ethane-1,2-diamine (L 2).The Schiff bases were prepared from the condensation reaction of ethylenediamine with benzaldehyde derivatives (4-chlorobenzaldehyde and 3-nitrobenzaldehyde).

Cobalt(II) salts interact with the hexadentate dioxime Schiff base ligands derived from triethylenetetramine and isonitroso ethylmethyl ketone (H 2 L′) or isonitrosopropiophenone (H 2 L″), to form two interesting types of complexes. With CoX 2 (X = Cl, NCS), binuclear, four-coordinated cobalt(II) complexes of the type [Co 2 (H 2 L)X 2]X 2 (L = L′, L″; X = Cl, NCS) are formed, which are.

Some Pb(II) complexes of dibasic tridentate Schiff base ligands derived from aldehydes/ketones and benzoylhydrazine have been synthesized and characterized by some physico-chemical studies; elemental, spectral (IR, UV, NMR, Mass), magnetic, and conductance analyses.

The CHN elemental analysis data showed the formation of [M:L] complexes. Theoretical investigation on the reactivity and photophysical properties of cobalt(II) and manganese(II) complexes constructed using Schiff base ligands based on ALIE and TDDFT calculations Coordination complexes constructed using Schiff base ligands were investigated for their global stability, reactivity and photophysical properties by.

Cobalt complexes with Schiff bases have received considerable attention in the fields of coordination chemistry and biological chemistry (6).

Cobalt functions as the active site of hydrolytic enzymes, such as carboxypeptidase and carbonic anhydrase where it is in a hard-donor coordination environment of nitrogen and oxygen (7).

Figure 1. General Structure of a Schiff base. cal activity of Schiff bases and their complexes. Biological Activities of Schiff Bases. Schiff bases are generally bi- or tridentate ligands capa-ble of forming very stable complexes with transition met-als. In organic synthesis, Schiff base reactions are useful in making carbon-nitrogen bonds.

Similar bands were observed in the spectra of Cobalt (II) Schiff base complex but in lower frequencies indicating that the Schiff base has coordinated to the respective metal ions. Other bands in the spectra of the cobalt (II) complex in the range cm-1 and cm-1 are assigned to v(M-N) and.

Immobilization of Schiff base cobalt(III) complexes on a gel‐type terpolymer obtained from glycidyl methacrylate (GMA, 20 mol %), styrene (S, 77 mol %) and diethyleneglycol dimethacrylate (DMDMG, 3 mol %) was carried out using a multi‐step procedure.

Suitable monomeric and dimeric structures have been proposed for these complexes Fig. 4 and 5. The Schiff base ligand and its cobalt(II), zinc(II) and copper(II) complexes were synthesized and characterized by elemental analyses, IR, UV-Vis, 1H and 13C-NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses(TGA).

Three Co(III) complexes of the type [Co(chel)(PBu 3)]ClO 4.H 2 O, (chel = 5-BrSalen, 5-MeOSalen and 4-MeOSalen), were synthesised and characterised by elemental analysis, IR, UV-Vis and 1 H NMR spectroscopy. In their electronic spectra, the absorptions between and nm of these complexes are attributable to the lowest d–d transition.

s1s of a polymer bolUld cobalt (II) Schiff base catalyst. To accomplish this, the introduction \vill be divided into four sections.

The first will give general information on polymer supports. The second \~ill. examine the use of polymer supports. Complexes of Schiff bases will be the focus of the third section. The binuclear Schiff base complexes prepared by condensation 2,6-diamino-pyridine and salicylaldehyde (LH) by using microwave and adding metal salts to ligand by same ratio.

The Schiff base ligand was checked by infrared, electronic spectra and 1 HNMR spectroscopy and prepared complexes characterized by molar conductivity, infrared, electronic spectra and susceptibility measurements. Abstract Current synthesis of cobalt (II) complexes of sulfonated binucleating Schiff base ligands requires the reaction be run under nitrogen.1 This research introduces a novel process in which the complex can be prepared in open cobalt (II) complexes are prepared with synthesized Esin İspir, Mükerrem Kurtoğlu, Fatih Purtaş, Selahattin Serin, Synthesis and Antimicrobial Activity of New Schiff Bases Having the –SiOR Group (R = CH 3 or CH2CH3), and their Transition Metal Complexes, Transition Metal Chemistry, /s, 30, 8, (), ().

The near-infrared spectrum of “square-planar”NN′-ethylenedi(salicylideneiminato)cobalt(II) in the solid state differs from that in dichloromethane the length of the di-imine bridge in the ligand is increased to seven or more methylene groups, the configurations of the resulting complexes change to distorted tetrahedral symmetry as indicated by magnetic and spectral evidence.

Synthesis, spectroscopic characterization and biological activity of the metal complexes of the Schiff base derived from phenylaminoacetohydrazide and dibenzoylmethane. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy71 (1), DOI: / INTRODUCTION.

Metal complexes of Schiff bases are extensively studied due to synthetic flexibility, selectivity and sensitivity towards a variety of metal atoms bases are most widely used as chelating ligands in coordination chemistry are also useful in catalysis and in medicine as antibiotics, antiallergic and antitumor agents metal complexes of Schiff bases derived from.

Cooperative influence of pseudohalides and ligand backbone of Schiff-bases on nuclearity and stereochemistry of cobalt(III) complexes: experimental and theoretical investigation A. Mandal, S. Dasgupta, S. Ganguly, A. Bauzá, A. Frontera and D. Das, Dalton Trans.,46, molar ratio of Both the Schiff base and the com- plex of Co(III) were characterized by IR, UV-vis, 1H NMR- and 13C NMR-spectroscopy techniques.

Single crystal X-ray diffraction investigation, at low tempera- ture T = K, shows that the cobalt complex is tri. Synthesis of a Cobalt Complex of a Sulfonated Binucleating Schiff Base Ligand Jieun Emily Hwang Abstract: Current synthesis of cobalt (II) complexes of sulfonated binucleating Schiff base ligands requires the reaction be run under nitrogen.1 This research introduces a novel process in which the complex can be prepared in open air.

Cobalt forms a complex since it has an empty valency shell orbital therefore it is an negatron brace acceptor. It can donate negatrons from the ligands therefore organizing a coordination compound. Cobalt normally exists in two oxidization stable provinces normally the +2 and +3 and can besides be in the signifier of a tetrahedral arragement.

One-Pot Self-Assembly of Dinuclear, Tetranuclear, and H-Bonding-Directed Polynuclear Cobalt(II), Cobalt(III), and Mixed-Valence Co(II)/Co(III) Complexes of Schiff Base. New transition metal complex of Cobalt(III) of the ligand (E)(1-(2-aminoethylimino)ethyl)hydroxy-2H-chromenone, derived from condensation of ethylene diamine with 3-acetylhydroxy-chromeneone have been synthesized by reaction of cobalt(III) salt and the ligand, in amounts equal to metal-ligand molar ratio of Both the Schiff base and the complex of Co(III) were characterized.

The activity of Schiff base ligand is usually increased by complexation with the metal ion. The copper complexes of Schiff bases have striking properties such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-tumor and cytotoxic activities, plant development controller, enzymatic activity and applications in pharmaceutical fields.

Synthesis of Schiff base metal complex and Lithium-Schiff base Cobalt(II) acetate tetrahydrate (5mmol) was dissolved in ethanol. The solution was treated with solution containing Schiff base (10mmol) in ethanol. The mixture was refluxed for 6 hours. The product was filtered, washed with cold ethanol and dried in vacuo over silica gel.

A series of six new mononuclear Schiff base complexes, 1–6 of cobalt(III) of the general formula, [CoLX] or its adduct with methanol, is reported.

The pentadentate Schiff base ligand (H 2 L) was obtained by the condensation of N-(3-aminopropyl)-N-methylpropane-1,3-diamine with 1-(2-hydroxyphenyl)ethanone (H 2 L 1) or 1-(2-hydroxyphenyl)propanone (H 2 L 2).

Crystal Structure Analysis of Co(III) Schiff Bases. Crystals of 3 and 6 suitable for X-ray crystallography were grown by slow evaporation from the reaction mixture and vapor diffusion of ether into methanol, respectively. Complexes 2, 4, 5 were converted to their respective tetraphenylborate salts through the dropwise addition of a saturated solution of NaBPh 4 in methanol to an aqueous.

New Schiff base ligand was synthesis via a condensation of the ligands in methanol. The Schiff base were synthesized in molar ratio reactions. The complexes [Mn(HL 1) 2 Cl, Cu(HL 1) 2 and Ni(HL 1) 2 Cl] have been characterized on the basis of FTIR, electronic spectra, melting points/decomposition temperature, solubility and molar conductance.

The in-vitro antibacterial activity. Co(II), Ni(II) and Cu(II) complexes of the two new Schiff base ligands (HL¹ and HL² derived from 2-hydroxymethoxybenzaldehyde and 2-hydroxynaphtaldehyde with 2,4-dimethoxyaniline) have. Herein, we report the synthesis and characterization of a new Schiff base ligand 3-[[(E)-(3-hydroxyphenyl)-methylidene]amino]methyl-quinazolin-4(3H)-one (HAMQ) and its Cd(II), Ni(II), Zn(II), and Cu(II) complexes (C1–C4).

The ligand HAMQ was synthesized by reacting 3-hydroxybenzaldehyde and 3-aminomethyl-4(3H)-quinazolinone in a molar ratio. The structure of. Show Summary Details.The synthesis and structural characterization of cobalt(II) complexes of amino acid Schiff bases was prepared from Salicylaldehyde and three amino acid (Valine, Leucine, and Isoleucine) in basic medium.

The metal complexes was synthesized by treating an ethanolic solution of the ligand with appropriate amount of metal salts [] [M:L] ratio. Synthesis of cobalt complexes [Cobalt sulindac complex], 1 was prepared by mixing cobalt chloride and potassium sulindac in molar ratios with methanol as a solvent.

The desired product was obtained as a yellow solid (Scheme 1) and its structure was determined by single crystal X-ray novel mixed ligand cobalt(II) complexes were prepared by adding the appropriate .

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