scholarly journals Synthesis, Characterization and Antimicrobial Studies of 3-[(2-Hydroxy-quinolin-3-ylmethylene)-amino]-2-phenyl-3H-quinazolin-4-one and its Metal(II) Complexes

2008 ◽  
Vol 5 (1) ◽  
pp. 155-162 ◽  
Author(s):  
K. Siddappa ◽  
Tukaram Reddy ◽  
M. Mallikarjun ◽  
C. V. Reddy

A new complexes of the type ML2 and M′L [where M=Cu(II), Co(II), and Ni(II) and M′= Zn(II), Cd(II) and Hg(II)]. L = 3-[(2-hydroxy-quinolin-3-ylmethylene)-amino]-2-phenyl-3H-quinazolin-4-one, (HQMAPQ) 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 HQMAPQ acts as doubly monodentate bridge for metal(II) ions and form mononuclear complexes. The complexes Ni(II), Co(II) and Cu(II) 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(II) complexes were screened for their antimicrobial activity.

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.


2020 ◽  
Vol 12 (1) ◽  
pp. 251-258
Author(s):  
S. Isyaku ◽  
H.N. Aliyu ◽  
E.C. Ozoro ◽  
T. Abubakar

Manganese(II) complexes of Schiff bases; 2-acetylthiophene-4‑phenylthiosemi-carbazone (AT-PTSC) and 2-furylmethylketone-4-phenylthiosemi-carbazone  (AF‑PTSC) derived from condensation of 2-acetylthiophene and 2-furylmethylketone (2-acetylfuran) each with 4-phenylthiosemicarbazide in (1:1 molar ratio) ethanol, have been synthesized. The Schiff bases and the Mn(II) complexes were characterized on the basis of melting point/decomposition temperature, solubility, magnetic susceptibility, infrared spectra, molar conductance measurements,  elemental and gravimetric  analyses. The Mn(II) complexes show moderate values of decomposition temperatures. The Schiff bases and the complexes were soluble in some common organic solvents. Infrared spectral data of the Schiff bases and their complexes, indicate coordination of the Schiff bases to the metal(II) ion via azomethine nitrogen. The effective magnetic moment of the Mn(II) complexes suggested an octahedral geometry. The molar conductance values of the complexes show that the complexes are electrolytes. The results of the elemental analysis of the ligands and their complexes are in good agreement with the calculated values, suggesting a 1:2 (metal-ligand) ratio. Antimicrobial screenings of the ligands and their complexes were conducted against gram-positive (Staphylococcus aureus,) and two gram-negative (Salmonella typhi, and Escherichia coli) bacteria specie. Also three fungi mainly (Candida albicans, Mucus indicus and Aspergillus flavus) were tested. The results showed that both the ligands and the complexes are active against the bacteria and the fungi specie. Keywords: Ligand, Schiff base, 4-phenylthiosemicarbazide, 2-acetylthiophene, 2-acetylfuran molar conductivity, magnetic susceptibility, elemental analysis.


2020 ◽  
Vol 12 (1) ◽  
pp. 85-92
Author(s):  
S. Isyaku ◽  
H.N. Aliyu ◽  
E.C. Ozoro ◽  
T. Abubakar

Manganese (II) complexes of Schiff bases; 2-acetylthiophene 4‑phenylthiosemi-carbazone (AT-PTSC) and 2-furylmethylketone-4-phenylthiosemi-carbazone (AF‑PTSC) derived from condensation of 2-acetylthiophene and 2-furylmethylketone (2-acetylfuran) each with 4-phenylthiosemicarbazide in (1:1 molar ratio) ethanol, have been synthesized. The Schiff bases and the Mn(II) complexes were characterized on the basis of melting point/decomposition temperature, solubility, magnetic susceptibility, infrared spectra, molar conductance measurements,  elemental and gravimetric  analyses. The Mn(II) complexes show moderate values of decomposition temperatures. The Schiff bases and the complexes were soluble in some common organic solvents. Infrared spectral data of the Schiff bases and their complexes, indicate coordination of the Schiff bases to the metal(II) ion via azomethine nitrogen. The effective magnetic moment of the Mn(II) complexes suggested an octahedral geometry. The molar conductance values of the complexes show that the complexes are electrolytes. The results of the elemental analysis of the ligands and their complexes are in good agreement with the calculated values, suggesting a 1:2 (metal-ligand) ratio. Antimicrobial screenings of the ligands and their complexes were conducted against gram-positive (Staphylococcus aureus,) and two gram-negative (Salmonella typhii, and Escherichia coli) bacteria specie. Also three fungi mainly (Candida albicans, Mucus indicus and Aspergillus flavus) were tested. The results showed that both the ligands and the complexes are active against the bacteria and the fungi specie. Keywords: Ligand, Schiff base, 4-phenylthiosemicarbazide, 2-acetylthiophene, 2-acetylfuran molar conductivity, magnetic susceptibility, elemental analysis.


2020 ◽  
Vol 4 (2) ◽  
pp. 452-458
Author(s):  
Abubakar Muhammad JABBI ◽  
Habu Nuhu Aliyu ◽  
Suleiman Ishaku ◽  
Abdullahi Muhammad Kabir

Schiff base derived from 2-aminophenol and 2-hydroxy-6-methoxy-3-quinolinecarboxaldehyde and its Co(II) and Ni(II) complexes were synthesized and characterized by elemental analysis, melting point and decomposition temperature, molar conductivity, IR spectral analysis, AAS analysis, solubility test, and magnetic susceptibility. The FTIR spectral data of the Schiff base determined showed a band at 1622cm-1  which was assigned to the v(C=N), a feature of azomethine group. The same band was observed to shift to lower frequencies 1577 and 1599cm-1 in the complexes suggesting coordination of the Schiff base with the respective metal (II) ions. Molar conductance values 14.58 and 12.65Ω-1cm2mol-1show that the metal complexes were non-electrolytic in nature. The magnetic susceptibility of the complexes were determined and the gram magnetic susceptibility of the complexes were found to be positive, revealing that they are paramagnetic. The elemental analysis of the complexes for C, N and H determined suggested (1:1) metal to ligand ratio.  The result of the antimicrobial studiesthat, the metal (II) complexes exhibited higher antibacterial and antifungal activity than the Schiff base but lower than the reference drugs Amoxicillin and Ketoconazole used as control in all cases.   


1997 ◽  
Vol 4 (2) ◽  
pp. 65-68 ◽  
Author(s):  
Zahid H. Chohan ◽  
Syed K. A. Sherazi

Metal(II) complexes of hydrazine derived Schiff-base ligands of the type M(L)2Cl2 where M = Co, Cu, Ni and Zn and L = L1 and L2 have been prepared and characterised by molar conductance, magnetic moment, elemental analysis and electronic, IR, H-NMR and C13 spectral data.The different modes of chelation of the ligands and their comparative biological properties against different bacterial species are reported.


2011 ◽  
Vol 8 (4) ◽  
pp. 1750-1764 ◽  
Author(s):  
Ambit Thakar ◽  
Krishnakant Joshi ◽  
Kishor Pandya ◽  
Arvind Pancholi

Transition metal complexes of Cr(III), Mn(II), Fe(II), Co(II), Ni(II) and Cu(II) metal ions with general stoichiometry [ML2.2H2O] and [ML3], where M= Mn(II), Cr(III), Fe(II), Co(II), Ni(II) and Cu(II), L= Schiff base derived from the condensation of 2-amino-4(4’-phenyl/methylphenyl)-5-methyl-thiazole with 4-acetyl-1(3-chloro phenyl)-3-methyl-2-pyrazoline-5-ones, have been synthesized and structurally characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements and spectral techniques like IR, UV,1H NMR,13C NMR and Mass Spectra. All the complexes were found to be octahedral geometry. The ligand and its complexes have been screened for their antifungal and antibacterial activities against three fungi,i.e. Alternaria brassicae, Aspergillus nigerandFesarium oxysporumand two bacteria,i.e. Xanthomonas compestrisandPseudomonas aeruginosa.


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.


2007 ◽  
Vol 4 (1) ◽  
pp. 39-45
Author(s):  
B. Basavaraju ◽  
H. S. Bhojya Naik ◽  
M. C. Prabhakara

The synthesis and characterisation of title complexes of the ligand Methylquinolino[3,2-b][1,5]benzodiazepine (MQBD) and Methyl-quinolino[3,2-b][1,5]benzoxazepine (MQBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR,1H NMR and UV-visible studies. They have the stoichiometry [ML2Cl2] where M=Co(II)/Ni(II), L=MQBD/MQBO and [MLCl2] where M=Zn(II)/Cd(II), L=MQBD/MQBO. The antibacterial and antifungal activity of the metal complexes has been investigated.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Aderoju Amoke Osowole

4-(Thiophen-3-yl)-aniline undergoes condensation with o-vanillin to form an ONS donor Schiff base, 2-methoxy-6-[(4-thiophene-3-yl-phenylimino)-methyl]-phenol, which forms complexes of the type [ML2]xH2O (where M = Mn, Co, Ni, Cu, Zn, Pd). These complexes are characterized by elemental analysis, 1H nmr, electronic, mass, and IR spectroscopies and conductance measurements. The electronic, IR and CHN data are supportive of a 4-coordinate tetrahedral geometry for Mn(II), Co(II), Ni(II), and Zn(II) complexes and square-planar geometry for Cu(II) and Pd(II) complexes, with the chromophores N2O2. The magnetic data reveals that the complexes are magnetically dilute and mononuclear with exception of the Cu(II) complex, which exhibits some anti-ferromagnetisms. The complexes are air-stable solids, and none is an electrolyte in nitro methane.


2019 ◽  
Vol 84 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Chinnaraj Kanagavalli ◽  
Murugesan Sankarganesh ◽  
Raja Dhaveethu ◽  
Manivannan Kalanithi

Novel series of Co(II), Ni(II) and Cu(II) transition metal complexes were synthesized from the Schiff base ligands HL1?HL4 derived from 2-amino-6- nitrobenzothiazole with various aromatic aldehydes, i.e., 4-methylbenzaldehyde, 4- ethylbenzaldehyde, 2-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, respectively. The ligands HL1?HL4 and their metal (II) complexes were characterized by atomic absorption spectroscopy (AAS), magnetic susceptibility and molar conductance measurements, and UV?Vis, FT-IR and NMR spectroscopic techniques. The spectroscopic studies revealed that the complexes of HL1?HL3 coordinated in an octahedral environment and L4 in square planar/tetrahedral geometry. The ligands HL1?HL4 and their metal(II) complexes were screened for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results suggest that the complexes of HL4 possess greater inhibition activity towards C. albicans. The nonlinear optics (NLO) activities of ligands HL1?HL4 were determined. The obtained results showed that ligands HL1 and HL2 have greater second harmonic generation (SHG) efficiency than HL3and HL4.


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