Mansoura Laboratory

of Justice, Egypt

Mansoura Laboratory

of Justice, Egypt
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El-Gammal O.A.,Mansoura University | Abu El-Reash G.M.,Mansoura University | Ghazy S.E.,Mansoura University | Yousef T.,Mansoura Laboratory
Journal of Coordination Chemistry | Year: 2012

Four Cu(II) complexes of N 1-phenyl-N 2-(pyridin-2-yl) hydrazine-1,2-bis(carbothioamide) (H 2PPS), N-phenyl-2-(2-(pyridin-2- ylcarbamothioyl)hydrazinyl)-2-thioxoacetamide (H 2PBO), N-phenyl-2-(pyridin-2-ylcarbamothioyl)hydrazinecarboxamide (H 2APO), and 1-(aminoN-(pyr-idin-2-yl)methanethio)-4-(pyridin-yl)thiosemicarbazide (H 2PPY) have been prepared and characterized by elemental analyses, spectral (infrared (IR), UV-Visible, 1H NMR, and electron spin resonance (ESR)) as well as magnetic and thermal measurements. Varying the substituents on the thiosemicarbazide led to remarkable modifications of the mode of coordination. IR spectral data reveal that the ligands are SN bidentate, NON tridentate, or NSNS tetradendate chelates forming structures in which copper is square-planar or octahedral. ESR spectra of these complexes are quite similar and exhibit an axially symmetric g-tensor parameter with g || > g ⊥ > 2.0023 revealing an appreciable covalency with d(x 2-y 2) as the ground-state. Bond lengths, bond angles, HOMO, LUMO, and dipole moments have been calculated to confirm the geometry of the thiosemicarbazide derivatives and their corresponding complexes. Proton-ligand dissociation and copper-ligand stability constants of all ligands were calculated pH-metrically. The effect of the compounds on calf thymus DNA was investigated. © 2012 Taylor & Francis.


This paper presents a combined experimental and computational study of novel Mn(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes of (E)-2-((3-hydroxynaphthalen-2-yl)methylene)-N-(pyridin-2-yl) hydrazinecarbothioamide (H 2L). The complexes have been characterized by elemental analyses, spectral (IR, UV-Vis, 1H NMR and 13C NMR), magnetic and thermal studies. Theoretical calculations have been performed to obtain IR spectra for the ligand and its complexes using AM1, MM, Zindo/1 and PM3 methods. Satisfactory theoretical-experimental agreements were achieved by the MM method for the ligand and PM3 for the metal complexes. Additional information is obtained from bond length calculations for all compounds by two methods, AM1 and MM. It was observed that the M-S bond length is longer than that of M-N in the Cu(II), Cd(II) and Mn(II) complexes and the M-O bond length is shorter than that of M-N in the case of the Ni(II) complex, and the same is noticed in the Zn(II) complex which contains M-O, M-N and M-S bonds and their bond lengths have the order M-S > M-N > M-O. DOS calculations were carried out by the MM (ADF) method for the ligand and the Cu complex, from which we concluded that the thiol form of the ligand is more active than thione form and this explains why most of the complexation is in that form. Also, valuable information is obtained from the calculation of molecular parameters for all compounds carried out by previous methods of calculation (electronegativity of the coordination sites, net dipole moment of the metal complexes, values of heat of formation and binding energy), which proved that the complexes are more stable than the ligand. The IR spectra show that H 2L is coordinated to the metal ions in a mono, bi or tridentate manner. Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Finally, biochemical studies showed that complexes 3 and 4 have a powerful and complete degradation effect on DNA. © 2012 Elsevier Ltd. All rights reserved.


Yousef T.A.,Mansoura Laboratory | Abu El-Reash G.M.,Mansoura University | El-Gammal O.A.,Mansoura University | Bedier R.A.,Mansoura University
Journal of Molecular Structure | Year: 2012

A new series of [Co(HPTP)Cl(H2O)2], [Cu(HPTP)Cl], [Cd(HPTP)Cl](H2O)4, [Fe(PTP)Cl(H2O) 2](H2O), [UO2(HPTP)(OAc)(H2O) 2] complexes of Schiff-bases derived from 4-(2-pyridyl)-3- thiosemicarbazide and pyruvic acid (H2PTP) have been synthesized and characterized by spectroscopic studies. Schiff-base exhibit thiol-thione tautomerism wherein sulfur plays an important role in the coordination. The coordination possibility of the Schiff-bases towards metal ions have been proposed in the light of elemental analyses, spectral (IR, UV-vis, 1H NMR, 13C NMR and ESR), magnetic and thermal studies. IR spectra show that H2PTP is coordinated to the metal ions in a mono or binegative tridentate manner. The electronic spectra of the complexes and their magnetic moments provide information about geometries. The room temperature solid state ESR spectra of the Cu(II) complexes show dx2- y2 as a ground state, suggesting square-planar geometry around Cu(II) center. The molecular parameters: total energy, binding energy, isolated atomic energy, electronic energy, heat of formation, dipole moment, HOMO and LUMO were calculated for the ligand and its complexes. Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Also, the optical band gap (Eg) of the metal complexes has been calculated. The optical transition energy (Eg) is direct and equals 3.25, 3.26, 3.34 and 3.27 eV for Co, Cu, Fe and U complexes, respectively. The synthesized ligand, in comparison to its metal complexes is screened for its antibacterial activity against bacterial species, Bacillus thuringiensis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The activity data show that the metal complexes to be more potent/antibacterial than the parent Schiff base ligand against one or more bacterial species. Finally, the biochemical studies showed that, Cu, Cd and Fe complexes have powerful and complete degradation effect on DNA. © 2012 Elsevier B.V. All rights reserved.


(E)-3-(2-(2-hydroxybenzylidene)hydrazinyl)-3-oxo-n(thiazole-2-yl) propane-mide (H2L) has been prepared and its structure confirmed by elemental analysis, IR and 1HNMR spectroscopy. It has been used to produce diverse complexes with Ni(II), Co(II) and Cu(II) ions. The complexes obtained have been investigated by thermal analysis, spectral studies (IR, UV-visible, ESR), and magnetic measurements. IR spectra suggest that the H 2L acts as a bidentate ligand coordinating via (CN)1 and (OH)phenolic or deprotonated enolized carbonyl oxygen (CO) 1. The electronic spectra of the complexes and their magnetic moments provide information about geometries. The room temperature solid state ESR spectra of the Cu(II) complexes show dx2-y2 as a ground state, suggesting tetragonally distorted octahedral or square-planar geometries around Cu(II) centre. The molar conductance measurements proved that the complexes are non-electrolytes. The bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated to confirm the geometry of the ligand and the investigated complexes. Also, thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of all thermal decomposition stages have been evaluated using Coats-Redfern and Horowitz-Metzger methods. Finally, the antimicrobial activity has been tested. © 2011 Elsevier B.V. All rights reserved.


Yousef T.A.,Mansoura Laboratory | El-Gammal O.A.,Mansoura University | Ghazy S.E.,Mansoura University | Abu El-Reash G.M.,Mansoura University
Journal of Molecular Structure | Year: 2011

Four new cobalt (II) complexes of some thiosemicarbazides have been synthesized and spectrochemically characterized. The thiosemicarbazides are prepared by the addition of 4-(2-pyridyl)-3-thiosemicarbazide to phenyl isothiocyanate (H 2PPS), benzoyl isothiocyanate (H 2PBO), phenyl isocyanate (H 2APO) and 2-pyridyl isothiocyanate (H 2PPY). The complexes are characterized by elemental analysis, spectral (IR, 1H NMR and UV-Vis), thermal and magnetic measurements. The studies revealed that structures of complexes are of two types octahedral and tetrahedral. The octahedral complexes are of H 2PPS, which acts as di-anionic tetradentate SSNN and H 2APO acts as mono-anionic tridentate NON. The tetrahedral complexes are of H 2PBO, which acts as di-anionic tridentate NSO and H 2PPY acts as mono-anionic bidentate NS. From the modelling studies, the bond length, bond angle, HOMO, LUMO and dipole moment had been calculated to confirm the geometry of the ligands and their investigated complexes. From TG and DTA studies kinetic parameters are determined using Coats-Redfern and Horowitz-Metzger methods. From pH metric studies at 298, 303 and 308 K and μ (0.1, 0.15 and 0.2) in 50% dioxane-water mixture the protonation constants of the ligands, the stepwise stability constants of the complexes and their thermodynamic parameters are calculated. © 2011 Elsevier B.V. All rights reserved.


Abu El-Reash G.M.,Mansoura University | El-Gammal O.A.,Mansoura University | El-Gamil M.M.,Mansoura Laboratory
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Cr(III), Mn(II) and Fe(III) complexes derived from the quadruple potential dithione heterocyclic thiosemicarbazide ligand (H2PET) have been prepared and characterized by conventional techniques. The isolated complexes were assigned the formulae, [Cr(HPET)(H2O)2Cl 2]·3H2O, [Mn(HPET)(H2O)Cl]2 and [Fe(HPET)(H2O)2Cl2]·H2O, respectively. IR data revealed that the ligand behaves as monobasic bidentate through (CN)py and (CS) groups in both Cr(III) and Fe(III) complexes. In the binuclear Mn(II) complex, H2PET acts as NSNS monobasic tetradente via (CN)py, (CS), (CS) and the new azomethine, (NC)* groups. An octahedral geometry for all complexes was proposed. The bond lengths, bond angles, HOMO, LUMO and dipole moment have been calculated by DFT using materials studio program to confirm the geometry of H2PET and its metal complexes. The ligand association constant and the stability constants of its complexes in addition to the thermodynamic parameters were calculated from pH metrically at 298, 308 and 318°K in 50% dioxane-water mixture, respectively. Also, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes were determined by Coats-Redfern and Horowitz-Metzger methods. Moreover, the anti-oxidant (using ABTS and DPPH methods), anti-hemolytic, and cytotoxic activities of the compounds have been tested. © 2012 Elsevier B.V. All rights reserved.


Yousef T.A.,Mansoura Laboratory | Abu El-Reash G.M.,Mansoura University | El Morshedy R.M.,Mansoura University
Journal of Molecular Structure | Year: 2013

The paper presents a combined experimental and computational study of novel Cr(III), Fe(III), Co(II), Hg(II) and U(VI) complexes of (E)-2-((3- hydroxynaphthalen-2-yl)methylene)-N-(pyridin-2-yl)hydrazinecarbothioamide (H2L). The ligand and its complexes have been characterized by elemental analyses, spectral (IR, UV-vis, 1H NMR and 13C NMR), magnetic and thermal studies. IR spectra show that H2L is coordinated to the metal ions in a mononegative bi or tri manner. The structures are suggested to be octahedral for all complexes except Hg(II) complex is tetrahedral. Theoretical calculations have been performed to obtain IR spectra of ligand and its complexes using AM1, MM, Zindo/1, MM+ and PM3, methods. Satisfactory theoretical-experimental agreements were achieved by MM method for the ligand and PM3 for its complexes. DOS calculations carried out by MM (ADF) method for ligand Hg complex from which we concluded that the thiol form of the ligand is more active than thione form and this explains that the most complexation take place in that form. The calculated IR vibrations of the metal complexes, using the PM3 method was the nearest method for the experimental data, and it could be used for all complexes. Also, valuable information are obtained from calculation of molecular parameters for all compounds carried out by the previous methods of calculation (electronegativity of the coordination sites, net dipole moment of the metal complexes, values of heat of formation and binding energy) which approved that the complexes are more stable than ligand. The low value of ΔE could be expected to indicate H2L molecule has high inclination to bind with the metal ions. Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Finally, the biochemical studies showed that, complex 2, 4 have powerful and complete degradation effect on DNA. For the foremost majority of cases the activity of the ligand is greatly enhanced by the presence of a metal ion. Thus presented results may be useful in design new more active or specific structures. © 2013 Elsevier Ltd. All rights reserved.


Yousef T.A.,Mansoura Laboratory | Abu El-Reash G.M.,Mansoura University | El-Gammal O.A.,Mansoura University | Bedier R.A.,Mansoura University
Journal of Molecular Structure | Year: 2013

A new series of Cr(III), Mn(II), Ni(II), Zn(II) and Hg(II) complexes of Schiff-bases derived from the condensation of 4-(2-pyridyl)-3-thiosemicarbazide and pyruvic acid (H2PTP) have been synthesized and characterized by spectroscopic studies. Schiff-base exhibit thiol-thione tautomerism wherein sulfur plays an important role in the coordination. The coordination possibility of the Schiff-bases towards metal ions have been proposed in the light of elemental analysis, spectral (IR, UV-vis, 1H NMR and 13C NMR), magnetic and thermal studies. IR spectra show that H2PTP is coordinated to the metal ions in a mononegative tridentate manner except in Cr(III) complex in which the ligand exhibits mononegative bidentate manner. The parameters total energy, binding energy, isolated atomic energy, electronic energy, heat of formation, dipole moment, HOMO and LUMO were calculated for the ligand and its complexes. Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Also, the optical band gap (Eg) of the metal complexes has been calculated. The optical transition energy (Eg) is direct and equals 3.20, 3.27 and 3.26 eV for Cr, Mn and Ni complexes, respectively. The synthesized ligand, in comparison to its metal complexes is screened for its antibacterial activity against the bacterial species, Bacillus thuringiensis, Staphylococcus aureus, Pseudomonas aeuroginosa and Escherichia coli. The results show that the metal complexes be more potent in activity antibacterial than the parent Shciff base ligand towards one or more bacterial species. Finally, the biochemical studies showed that, Mn complex have powerful and complete degradation effect on DNA. © 2012 Elsevier B.V. All rights reserved.


Zaky R.R.,Mansoura University | Yousef T.A.,Mansoura University | Yousef T.A.,Mansoura Laboratory | Ibrahim K.M.,Mansoura University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The o-Hydroxy acetophenone [N-(3-hydroxy-2-naphthoyl)] hydrazone (H 2o-HAHNH) has been prepared and its structure is confirmed by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. It has been used to produce diverse complexes with Co(II), Cd(II), Hg(II) and U(VI)O2 ions. The isolated complexes have been investigated by elemental analysis, magnetic measurements, molar conductivity, thermal (TG, DTG) and spectral (1H NMR, 13C NMR, IR, UV-visible, MS) studies. Infrared spectra suggested H2o-HAHNH acts as a bidentate and/or tridentate ligand. The electronic spectrum of [Co(Ho-HAHNH)2] complex as well as its magnetic moments suggesting octahedral geometry around Co(II) center. The TG analyses suggest high stability for most complexes followed by thermal decomposition in different steps. Moreover, the kinetic and thermodynamic parameters (Ea, A, ΔH, ΔS and ΔG) for the different decomposition steps of the [Co(Ho-HAHNH)2] and [Cd(Ho-HAHNH)2] complexes were calculated using the Coats-Redfern and Horowitz-Metzger methods. Moreover, the antibacterial and antifungal activities of the isolated compounds were studied using a wide spectrum of bacterial and fungal strains. © 2012 Elsevier B.V. All rights reserved.


El-Gammal O.A.,Mansoura University | Abu El-Reash G.M.,Mansoura University | El-Gamil M.M.,Mansoura Laboratory
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

Binuclear Cu(II), Co(II) and Ni(II) complexes derived from N 1-ethyl-N2-(pyridin-2-yl) hydrazine-1,2- bis(carbothioamide) (H2PET) have been prepared and characterized by elemental analysis, spectral (IR, UV-vis, EI mass, ESR and 1HNMR) and magnetic measurements. The isolated complexes assigned the general formula, [M(HPET)(H2O)nCl]2·xH2O where M = Cu(II), Co(II) and Ni(II), n = 2, 1, 0 and x = 0, 0.5 and 0, respectively. IR data revealed that the ligand behaves as monobasic tridentate through (CN)py, (C-S) and new azomethine, (NC) groups in the Co(II) complex but in Cu(II) complex, the ligand coordinate via both (CS) groups, one of them in thiol form as well as the new azomethine group. In Ni(II) complex, H 2PET acts as NSNS monobasic tetradente via (CN)py, (C-S), (CS) and the new azomethine, (NC) groups. An octahedral geometry is proposed for all complexes. pH- metric titration was carried out in 50% dioxane-water mixture at 298, 308 and 318 °K, respectively and the dissociation constant of the ligand as well as the stability constants of its complexes were evaluated. Also the kinetic and thermodynamic parameters for the different thermal decomposition steps of the complexes were determined by Coats-Redfern and Horowitz-Metzger methods. Moreover, the anti-oxidant, anti-hemolytic, and cytotoxic activities of the compounds have been tested. © 2012 Elsevier B.V. All rights reserved.

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