Metal Complexes of Schiff Bases: Preparation, Characterization, and Biological Activity

Gehad Geindy MOHAMED; Mohamed Mohamed OMAR; Ahmed Mohamed HINDY

Makale detayları

Metal Complexes of Schiff Bases: Preparation, Characterization, and Biological Activity

Yazarlar:

Gehad Geindy MOHAMED | Mohamed Mohamed OMAR | Ahmed Mohamed HINDY

Yayıncı:

TUBITAK

Ana Başlıklar:

Uygulamalı fizik

Dergi:

Turkish Journal of Chemistry 2006 Vol.30 Issue 3, pp.361-382

Belge Tipi:

Makale

Yayın Tarihi:

2/2006

Belge Dili:

İngilizce

Document ID (Org No.):

2000728906

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527

Özet:

 

Metal complexes of Schiff bases derived from  2-furancarboxaldehyde and o-phenylenediamine (L1), and  2-thiophenecarboxaldehyde and 2-aminothiophenol (HL2) are reported  and characterized based on elemental analyses, IR 1H NMR, solid  reflectance, magnetic moment, molar conductance, and thermal analysis  (TGA).  The ligand dissociation, as well as the metal-ligand stability  constants were calculated, pH-metrically, at 25 °C and ionic strength  m = 0.1 (1 M NaCl).  The complexes are found to have the formulae  [M(L1)(H2O)2](Cl)n \cdot yH2O (where M = Fe(III), Ni(II), Cu(II);  n = 2-3, y = 2-4); [M(L1)](X)2 \cdot yH2O (where M = Co(II),  Zn(II), UO2(II), X = Cl, AcO or NO3, y = 1-3); [M(L2)2] \cdot  yH2O (where M = Co(II), Ni(II), Cu(II); X = Cl; y = 0-2 and Zn(II); X  = AcO, y = 0); and [Fe(L2)2]Cl \cdot 2H2O and [UO2(HL2)2](NO3)2.   The molar conductance data reveal that all the metal chelates of the  L1 ligand, and Fe(III) and UO2(II) chelates of HL2 are  electrolytes, while Co(II), Ni(II), Cu(II), and Zn(II) chelates of  HL2 are non-electrolytes.  IR spectra show that L1 is coordinated to  the metal ions in a tetradentate manner, with ONNO donor sites of  azomethine--N and furan-O, whereas the HL2 ligand is coordinated to  the metal ions in a terdentate manner with SNS donor sites of  azomethine--N, thiophene-S, and thiol-S. From the magnetic and solid  reflectance spectra, it is found that the geometrical structures of  these complexes are octahedral and tetrahedral.  The thermal behavior  of these chelates shows that the hydrated complexes lose water  molecules of hydration in the first step and is immediately followed  by decomposition of the anions and ligand molecules in the subsequent  steps.  The activation thermodynamic parameters, such as E*, D  H*, D S*, and D G*, are calculated from the DrTG curves  using the Coats-Redfern method.  The synthesized ligands, in  comparison to their metal complexes, were also screened for their  antibacterial activity against bacterial species, Escherichia coli,  Pseudomonas aeruginosa, and Staphylococcus Pyogones, as well as  fungi (Candida).  The activity data show the metal complexes to be  more potent antibacterials than the parent Schiff base ligand against  one or more bacterial species.

 

Metal complexes of Schiff bases derived from  2-furancarboxaldehyde and o-phenylenediamine (L1), and  2-thiophenecarboxaldehyde and 2-aminothiophenol (HL2) are reported  and characterized based on elemental analyses, IR 1H NMR, solid  reflectance, magnetic moment, molar conductance, and thermal analysis  (TGA).  The ligand dissociation, as well as the metal-ligand stability  constants were calculated, pH-metrically, at 25 °C and ionic strength  m = 0.1 (1 M NaCl).  The complexes are found to have the formulae  [M(L1)(H2O)2](Cl)n \cdot yH2O (where M = Fe(III), Ni(II), Cu(II);  n = 2-3, y = 2-4); [M(L1)](X)2 \cdot yH2O (where M = Co(II),  Zn(II), UO2(II), X = Cl, AcO or NO3, y = 1-3); [M(L2)2] \cdot  yH2O (where M = Co(II), Ni(II), Cu(II); X = Cl; y = 0-2 and Zn(II); X  = AcO, y = 0); and [Fe(L2)2]Cl \cdot 2H2O and [UO2(HL2)2](NO3)2.   The molar conductance data reveal that all the metal chelates of the  L1 ligand, and Fe(III) and UO2(II) chelates of HL2 are  electrolytes, while Co(II), Ni(II), Cu(II), and Zn(II) chelates of  HL2 are non-electrolytes.  IR spectra show that L1 is coordinated to  the metal ions in a tetradentate manner, with ONNO donor sites of  azomethine--N and furan-O, whereas the HL2 ligand is coordinated to  the metal ions in a terdentate manner with SNS donor sites of  azomethine--N, thiophene-S, and thiol-S. From the magnetic and solid  reflectance spectra, it is found that the geometrical structures of  these complexes are octahedral and tetrahedral.  The thermal behavior  of these chelates shows that the hydrated complexes lose water  molecules of hydration in the first step and is immediately followed  by decomposition of the anions and ligand molecules in the subsequent  steps.  The activation thermodynamic parameters, such as E*, D  H*, D S*, and D G*, are calculated from the DrTG curves  using the Coats-Redfern method.  The synthesized ligands, in  comparison to their metal complexes, were also screened for their  antibacterial activity against bacterial species, Escherichia coli,  Pseudomonas aeruginosa, and Staphylococcus Pyogones, as well as  fungi (Candida).  The activity data show the metal complexes to be  more potent antibacterials than the parent Schiff base ligand against  one or more bacterial species.

Makale detayları

Metal Complexes of Schiff Bases: Preparation, Characterization, and Biological Activity

Yazarlar: Gehad Geindy MOHAMED | Mohamed Mohamed OMAR | Ahmed Mohamed HINDY

Yayıncı: TUBITAK

Ana Başlıklar: Uygulamalı fizik

Dergi: Turkish Journal of Chemistry 2006 Vol.30 Issue 3, pp.361-382

Belge Tipi: Makale

Yayın Tarihi: 2/2006

Belge Dili: İngilizce

Document ID (Org No.): 2000728906

Sıklık: İki Aylık

eISSN: 1303-6130

pISSN: 1300-0527

Sayı

Yazarlar:

Gehad Geindy MOHAMED | Mohamed Mohamed OMAR | Ahmed Mohamed HINDY

Yayıncı:

TUBITAK

Ana Başlıklar:

Uygulamalı fizik

Dergi:

Turkish Journal of Chemistry 2006 Vol.30 Issue 3, pp.361-382

Belge Tipi:

Makale

Yayın Tarihi:

2/2006

Belge Dili:

İngilizce

Document ID (Org No.):

2000728906

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527