scholarly journals Microwave Synthesis, Spectral, Thermal and Antimicrobial Studies of Some Co(II), Ni(II) and Cu(II) Complexes Containing 2-Aminothiazole Moiety

2012 ◽  
Vol 9 (4) ◽  
pp. 1655-1666 ◽  
Author(s):  
A. P. Mishra ◽  
H. Purwar ◽  
Rajendra K. Jain ◽  
S. K. Gupta

Some new Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 4-chlorobenzylidene-2-aminothiazole (CAT) and 2-nitrobenzylidene-2-aminothiazole (NAT) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility, thermal, electrical conductivity and XRD analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal:ligand) ratio with coordination number 4 or 6. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes have been determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria;Staphylococcus aureusand Gram-negative bacteria;Escherichia coliand fungiAspergillus nigerandCandida albicans.

2012 ◽  
Vol 77 (8) ◽  
pp. 1013-1029 ◽  
Author(s):  
Rajendra Jain ◽  
Anand Mishra

Some novel Schiff base metal complexes of Cr(III), Co(II), Ni(II) and Cu(II) derived from 2-[(5-bromo-2-hydroxybenzylidene)amino]pyridin-3-ol (BSAP) and {5-chloro-2-[(2-hydroxynaphthylidene)amino]phenyl}-phenylmethanone (HNAC) were synthesized by conventional as well as microwave methods. These compounds were characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility, thermal, cyclic voltammetry, electrical conductivity and XRD analyses. Analytical data revealed that all the complexes exhibited 1:1 (metal:ligand) ratio with coordination number 4 or 6. IR data showed that the ligand coordinates with the metal ions in a tridentate manner. FAB-mass and thermal data showed degradation pattern of the complexes. The thermal behaviour of metal complexes showed that the hydrated complexes lose water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes were determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The solid state electrical conductivity of the metal complexes was also measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes displayed a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans. The antimicrobial results also indicate that the metal complexes displayed better antimicrobial activity as compared to the Schiff bases.


2012 ◽  
Vol 9 (3) ◽  
pp. 1113-1121 ◽  
Author(s):  
A. P. Mishra ◽  
A. Tiwari ◽  
S. K. Gupta ◽  
Rajendra Jain

Some new Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 3-chloro-4-fluoroaniline (HL1) and 4-fluoroaniline (HL2) with 2-thiophenecarboxaldehyde have been synthesized and characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR and magnetic susceptibility. The complexes exhibit coordination number 4 or 6. The complexes are colored and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand) ratio. FAB-mass data show degradation pattern of the complexes. The Schiff base and metal complexes show a good activity against the bacteria;B. subtilis,E. coliandS. aureusand fungiA. niger,A. flavusandC. albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases.


2012 ◽  
Vol 9 (4) ◽  
pp. 1721-1727 ◽  
Author(s):  
Rajendra K. Jain ◽  
A. P. Mishra ◽  
D. K. Mishra ◽  
S. K. Gupta

Microwave-assisted synthesis is a branch of green chemistry. The salient features of microwave approach are shorter reaction times, simple reaction conditions and enhancements in yields. Some new Schiff base complexes of Cr(III), Co(II), Ni(II) and Cu(II) derived from 5-bromosalicylaldehyde with 4-nitro-1,2-phenylenediamine (H2L1) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility and thermal analysis. The complexes exhibit coordination number 4 or 6. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:1 (metal: ligand) ratio. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes.


2009 ◽  
Vol 6 (3) ◽  
pp. 615-624 ◽  
Author(s):  
K. Siddappa ◽  
K. Mallikarjun ◽  
Tukaram Reddy ◽  
M. Mallikarjun ◽  
C. V. Reddy ◽  
...  

A new complexes of the type ML, MʹL and M″L [where M=Cu(II), Co(II), Ni(II) and Mn(II), Mʹ=Fe(III) and M″=Zn(II), Cd(II) and Hg(II) and L=N1-[(1E)-1-(2-hydroxyphenyl)ethylidene]-2-oxo-2H-chromene- 3-carbohydrazide (HL)] Schiff base have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, IR,1H NMR, UV-Visible and ESR data. The studies indicate the HL acts as doubly monodentate bridge for metal ions and form mononuclear complexes. The complexes Ni(II), Co(II), Cu(II) Mn(II) and Fe(III) complexes are found to be octahedral, where as Zn(II), Cd(II) and Hg(II) complexes are four coordinated with tetrahedral geometry. The synthesized ligand and its metal complexes were screened for their antimicrobial activity.


2019 ◽  
Vol 31 (9) ◽  
pp. 2095-2100
Author(s):  
P. Priya ◽  
S. Vedanayaki ◽  
P. Jayaseelan

A new Schiff base ligand (L) N-(4-fluorophenyl)-1-(4-(((4-fluorophenyl)imino)methyl)phenyl)- methaninmine was prepared by the condensation of terephthalaldehyde with 4-fluoroaniline in 1:2 molar ratio. The mononuclear complexes of Co(II), Ni(II), Cu(II) and Zn(II) (1-4) have been synthesized in (2:1) ligand to metal ratio. The composition, geometry and binding sites of ligand with metal complexes were evidenced by various spectral methods like molar conductance, elemental analytical data, magnetic measurements, UV-visible, 1H & 13C NMR, ESI-MS, FT-IR, ESR and thermal analysis. The above studies shows that the ligand is a bidentate and its metal complexes possess an octahedral geometry. Oxidative cleavage of DNA studies of the complexes were monitored by super helix PUC18DNA using a method of agarose gel electrophoresis. Ligand and its metal complexes were screened against gram positive (Staphylococcus aureus), gram negative (Klebsiella pneumoniae) bacterium and fungus (Candida albicans) strains. Antioxidant activities of the metal complexes possess greater activity than ligand.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Har Lal Singh ◽  
J. B. Singh

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
R. B. Sumathi ◽  
M. B. Halli

A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass,1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2and MLCl2where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method.


Author(s):  
Umar Dalha ◽  
Aminu Ahmad ◽  
Sunusi Yahaya ◽  
I.U. Kutama

Schiff base ligand derived from condensation of 2-aminothiophenol and 2‑thiophenecarboxyldehyde was synthesized and used for the preparation of Ni(II) and Cd(II) complexes. The synthesized ligand and complexes were analyzed by decomposition temperature, solubility, magnetic susceptibility, molar conductance and infrared spectra. The decomposition temperatures of the complexes are 212 and 221°C. Molar conductance values are 16.12 and 12.60 ohm-1cm2mol-1 respectively. New bands appeared in the IR spectra of the complexes in the range of 519 - 475 cm-1 and 462 - 448 cm-1 which indicate υ (M - N) and υ (M - S) vibrations respectively. Magnetic susceptibility measurement indicated that Ni (II) complex is paramagnetic whileCd(II) complex is diamagnetic. The solubility test revealed that all complexes and ligand are soluble in DMSO. The analytical data show the formation of 2:1 metal to ligand ratio for all complexes and suggested the formula [ML2].nH2O. The ligand and metal chelates have been studied for microbial activity using well diffusion method against selected bacteria and fungi. The results signify that Ni(II) and Cd(II) metal complexes inhibit more compared with Schiff base ligand against the same test organisms.


Author(s):  
Fatimah A. Abdulsayid ◽  
Hamad M. Adress Hasan ◽  
Roaa A. Bouagila

Four metal complexes of Co(II), Pb(II),  Ni(II) and Fe(II) ions with a Schiff base derived from (3-methoxy-4-hydroxy-benzaldehyde with leucine) have been synthesized and characterized using several physical techniques, in particular; molar conductance measurements, colour, melting point,  infrared and electronic spectra. The molar conductance values reveal a non-electrolytic nature. The infrared spectral data display the coordination behaviour of the Schiff base toward Co(ll) ,pb(ll) ,Ni(ll) and Fe(ll) ions. The electronic absorption spectra of the Schiff base and its complexes show π→π* (phenyl ring) and, n→π* (HC=N) and the expected geometrical structure for the prepared complexes. The Schiff base and its complexes were tested for antimicrobial activity against gram-positive bacteria; Staphylococcus aurous; E. Coli and Klebsiella, in addition Rizopus as fungal. The effect of the Schiff base leucine complex on bacteria was recorded only against Staphylococcus aureus and Escherichia coli.


2021 ◽  
Vol 42 (1) ◽  
pp. 56-63
Author(s):  
Bharat Prasad Sharma ◽  
Sarvesh Kumar Pandey ◽  
Bishnu Prasad Marasini ◽  
Sabita Shrestha ◽  
Motee Lal Sharma

Schiff bases have been synthesized by the reaction of triazole containing primary amine with aromatic carbonyl compounds. The Schiff bases prepared, act as ligand when these are made in contact with oxovanadium (VO2+) ion. Some new mononuclear oxovanadium(IV) complexes have been synthesized by the reaction of Schiff base ligands with vanadyl sulphate (VOSO4.xH2O)  and the complexes are analyzed by different spectroscopic methods; [fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis.), electron paramagnetic resonance (EPR)], X-ray diffraction (XRD) analysis, elemental analysis, and conductivity measurement. The complexes have been well characterized based on analytical data. The electrolytic nature of the complexes was determined based on the molar conductance values. The powder XRD pattern has been used to determine crystal size and type. The synthesized Schiff base ligands and oxovanadium(IV) complexes were found to be stable in air and moisture at room temperature. On the basis of the physicochemical data, the tentative geometry of the complexes has been proposed. Antibacterial sensitivity of the ligand and its metal complexes have been assayed in vitro against bacterial pathogens viz. growth inhibitory activity of ligands and complexes against pathogens has also been determined.


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