Abdel-Nasser M.A. Alaghaz

Synthesis, spectroscopic, molecular orbital calculation, cytotoxic, molecular docking of DNA binding and DNA cleavage studies of transition metal complexes with N-benzylidene-N′-salicylidene-1,1-diaminopropane

Eight mononuclear chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) complexes of Schiffs base ligand were synthesized and determined by different physical techniques. The complexes are insoluble in common organic solvents but soluble in DMF and DMSO. The measured molar conductance values in DMSO indicate that the complexes are non-electrolytic in nature. All the eight metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The analytical data helped to elucidate the structure of the metal complexes. The Schiff base is found to act as tridentate ligand using N2O donor set of atoms leading to an octahedral geometry for the complexes around all the metal ions. Quantum chemical calculations were performed with semi-empirical method to find the optimum geometry of the ligand and its complexes. Additionally in silico, the docking studies and the calculated pharmacokinetic parameters show promising futures for application of the ligand and complexes as high potency agents for DNA binding activity. The interaction of the complexes with calf thymus DNA (CT-DNA) has been investigated by UV absorption method, and the mode of CT-DNA binding to the complexes has been explored. Furthermore, the DNA cleavage activity by the complexes was performed. The Schiff base and their complexes have been screened for their antibacterial activity against bacterial strains [Staphylococcus aureus (RCMB010027), Staphylococcus epidermidis (RCMB010024), Bacillis subtilis (RCMB010063), Proteous vulgaris (RCMB 010085), Klebsiella pneumonia (RCMB 010093) and Shigella flexneri (RCMB 0100542)] and fungi [(Aspergillus fumigates (RCMB 02564), Aspergillus clavatus (RCMB 02593) and Candida albicans (RCMB05035)] by disk diffusion method. All the metal complexes have potent biocidal activity than the free ligand.

Physicochemical Investigation on the Complexes of Co(II), Ni(II) and Cu(II) with Aminocyclodiphosph(V)azane Derivative

Co(II), Ni(II), and Cu(II) form 2:1 complexes with aminocyclodiphosph(V)azane derivative. The complexes have been investigated in solution by the spectrophometric molar ratio and conductometeric methods. The ligand and its complexes have been isolated in solid state and characterized on the basis of microanalytical, infrared, electronic, magnetic moment, 1 H NMR and mass spectral data. The cobalt and nickel complexes were assigned to be in tetrahedral structure while the copper complex is assigned to be in square planar.

New Tetrachlorocyclodiphosph(V)azane Complexes of Co(II), Ni(II), and Cu(II): Preparation, Characterization, Solid State Electrical Conductivity, and Biological Activity Studies

Tetrachlorocyclodiphosph(V)azane of thiazole, H2L (1,3-diphenyl -2,4-bis(3-phenyl-2-iminothiazole)-2,2,4,4-tetrachlorocyclodiphos(V)azane, reacts with stoichiometric amounts of transition metal salts such as Co(II), Ni(II), and Cu(II) to afford colored complexes in a moderate to high yield. The structure of the isolated complexes was suggested based on elemental analyses, IR, molar conductance, UV-Vis, 1H and 31P NMR, mass spectra, solid reflectance, magnetic susceptibility measurements and dark electrical conductivity of solid state from room temperature up to 450 k. The data obtained obeyed the relation σ = σ ° exp (−E/2kT) over the temperature range 30–150°C. The observed conductivities of the different complexes follow the order Co < Ni < Cu. It is clear that this trend is depending on the decreasing of the ionic radii and the increasing stability of metal complexes. The calculated mobility of charge carriers is ranged from 10−5 to 10−9 cm2/V s suggesting that the conduction of the studied complexes takes place by hopping mechanism. The solid-state electrical conductivity obtained reveals that the metal complexes behave as semiconducting materials. The powder XRD studies confirm the amorphous nature of the complexes. From the elemental analyses data, 1: 2 (H2L: M) ratio is suggested and the complexes are found to have the general formula [(MX2)2(H2L)(H2O) m ]. nH2O where M = Co(II) (X = SCN, n = 2, m = 0), Ni(II) (X = Cl, n = 4, m = 4), and Cu(II) (X = Cl, n = 2, m = 0). The complexes have been investigated in solution by the spectrophotometric molar ratio and conductometric methods. IR spectra show that the ligand is coordinated to the metal ions in a bidentate manner with NN donor sites of the imine NH and thiazole N. The UV-Vis, solid reflectance, and magnetic-moment data have shown that the ligand is coordinated to the metal ions in an octahedral, tetrahedral, or square planar manner. The molar conductance data show that the complexes are nonelectrolytes. The prepared complexes showed high to moderate bactericidal activity compared with the ligand.

Complexes of Co(II), Ni(II), Cu(II), and Pd(II) with Sulfametrole-Cyclodiphosph(V)azane Derivatives

Novel [1,3-di-[N 1 -4-methoxy-1,2,5-thiadiazole-3-yl-sulfanilamide(sulfametrole)]-2″4-bis-[1,3-dithiole-2-thione-4,5-dithiolate]-2′,4′-dichl-orocyclodiphosph(V)azane] (III) , was prepared and their coordinating behavior towards the metal ions Co(II), Ni(II), Cu(II), and Pd(II) was studied. The structures of the isolated products are proposed based on elemental analyses, IR, UV, 1 H, and 31 P NMR, ESR, magnetic susceptibility, molar ratio, conductometric titration and electrical conductivity measurements. The prepared complexes showed high to moderate bactericidal activity compared with the ligand.

Preparation and Biological Activity of Some Novel Tetrachlorocyclodiphosph (V) Azane Pyridazine Derivatives and Its Metal Complexes

1,3-diphenyl-2,2,4,4-tetrachloro-2,4-bis(4-Cyano-5,6-dimethyl-py-ridazin-3(2H)-one) cyclodiphosph(V)azane(III), reacts with stoichiometric amounts of transition metal salts such as Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and UO2(II) to afford colored complexes in a moderate to high yield. The complexes have been investigated in solution by the spectrophotometric molar ratio and conductometeric methods. The formula of the isolated complexes was suggested based on elemental analyses, IR, molar conductance, UV-Vis, 1H NMR, mass spectra, solid reflectance, and magnetic susceptibility measurements. From the elemental analyses data, 1: 2 (III : M) ratio is suggested and the complexes are found to have the general formula [(MXn)2(III)(H2O)m].yX where M = Mn(II) (X = OCOCH 3 , n = 2, m = 4, y = 0), Fe(III) (X = Cl, n = 2, m = 2, y = 2), Fe(II) (X = SO4, n = 1, m = 2, y = 0), Co(II) (X = OCOCH3, n = 2, m = 4, y = 0), Ni(II) (X = OCOCH3, n = 2, m = 4, y = 0), Cu(II) (X = OCOCH3, n = 2, m = 4, y = 0), Zn(II) (X = OCOCH3, n = 2, m = 4, y = 0), Cd(II) (X = Cl, n = 2, m = 4, y = 0), and UO2(II) (X = NO3, n = 1, m = 0, y = 2). The IR and 1H NMR spectral data revealed that III behaves as a neutral bidentate ligand coordinated to the metal ions through oxygen (O) and nitrogen N atoms. The UV-Vis, solid reflectance, and magnetic-moment data have shown that the ligands are coordinated to the metal ions in an octahedral manner. The molar conductance data show that the complexes are nonelectrolytes while the Fe(III) and UO2(II) complexes are 1:2 electrolytes. The in vitro–biological activity of some newly synthesized compounds against gram-positive and gram-negative bacteria was studied.

Spectral and Biological Activity Properties of Some New Aminocyclodiphosph(V)azane Derivatives and Their Complexes

The ligand aminocyclodiphosph(V)azane derivative (III) and its complexes with Co(II), Ni(II), Cu(II) and Pd(II) ions were prepared and characterized by microanalytical, FTIR, 1H and 31P NMR, UV/Visible, analysis and magnetic moments. The ligand acts in a tetrahedral manner forming 2:1 metal to ligand ratio. Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for Co(II), Ni(II) and Cu(II) complexes and square planar geometry for Pd(II) complex. The powder XRD studies confirm the amorphous nature of the complexes. The free ligand (III) and its metal complexes have been tested in vitro against Alternarie alternate, Aspergillus flavus, Aspergillus nidulans and Aspergillus niger fungi and Streptococcus, Staph, Staphylococcus and Escherchia coli bacteria in order to assess their antimicrobial potential. The results indicate that the ligand and its metal complexes possess antimicrobial properties.

Studies of Some New Aminocyclodiphosphazane Complexes of Co(II), Ni(II), and Cu(II)

The ligand aminocyclodiphosph(V)azane derivative (III) and its complexes with Co(II), Ni(II), and Cu(II) ions were prepared and characterized by microanalytical, FTIR, 1H, 13C, and 31P-NMR, UV/Visible, thermogravimetric (TGA) analysis, and magnetic moments. The ligand acts in a tetrahedral manner forming 2:1 metal to ligand ratio. The copper complex is assigned to be tetrahedral while cobalt and nickel complexes were assigned to be octahedral structure.

Spectral and quantum chemical studies on 1,3-bis(N1-4-amino-6-methoxypyrimidinebenzenesulfonamide-2,2,4,4-ethane-1,2-dithiol)-2,4-dichlorocyclodiphosph(V)azane and its erbium complex

Novel 1,3-bis(N(1)-4-amino-6-methoxypyrimidine-benzenesulfonamide-2,2,4,4-ethane-1,2-dithiol)-2,4-dichlorocyclodiphosph(V)azane (L), was prepared and their coordinating behavior towards the lanthanide ion Er(III) was studied. The structures of the isolated products are proposed based on elemental analyses, IR, UV-VIS., (1)H NMR, (13)C NMR, (31)P NMR, SEM, XRD, mass spectra, effective magnetic susceptibility measurements and thermogravimetric analysis (TGA). Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of L and its binuclear Er(III) complex. Different tautomers of the ligand were optimized at the ab initio DFT level. Keto-form structure is about 17.7 kcal/mol more stable than the enol form (taking zpe correction into account). Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which compared by the measured electronic spectra.

Synthesis, Spectral Characterization, and Thermal and Cytotoxicity Studies of Cr(III), Ru(III), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) Complexes of Schiff Base Derived from 5-Hydroxymethylfuran-2-carbaldehyde

Coordination compounds of Cr(III), Ru(III), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions were synthesized from the furan ligand [5-hydroxymethylfuran-2-yl-methyleneaminoquinolin-2-one] (H-MFMAQ) derived from the condensation of 5-hydroxymethylfuran-2-carbaldehyde and 1-aminoquinolin-2(1H)-one. Elemental analytical data, IR, NMR (1H, 13C, and 15N), EPR, XRD, SEM, TEM, EDX, TGA, mass, molar conductance, magnetic moment, and UV-Visible spectra techniques were used to confirm the structure of the synthesized chelates. According to the data obtained, the composition of the 1 : 1 metal ions : furan Schiff base ligand was found to be [M(MFMAQ)Cl2] (M = Cr(III) and Ru(III)) and [M(MFMAQ)Cl(H2O)]·nH2O in which (M = Mn(II); , Co(II); , Ni(II); , Cu(II); and Zn(II); ). The measurements of magnetic susceptibility, ligand field parameter, and reflectance spectra suggested an octahedral geometry for the complexes. Central metals ions and furan Schiff base coordinated via O3 and N donor sites which was observed from IR spectra. The cytotoxic activities of all inspected compounds were evaluated towards human breast (MCF-7) and lung cancer (A549) cell lines.

Synthesis, spectral and quantum chemical studies on NO-chelating sulfamonomethoxine-cyclophosph(V)azane and its Er(III) complex.

Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of novel ethane-1,2-diol-dichlorocyclophosph(V)azane of sulfamonomethoxine (L), and its binuclear Er(III) complex. Different tautomers of the ligand were optimized at the ab initio DFT level. Keto-form structure is about 15.8 kcal/mol more stable than the enol form (taking zpe correction into account). Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which show good agreement with measured electronic spectra. The structures of the novel isolated products are proposed based on elemental analyses, IR, UV-VIS, (1)H NMR, (31)P NMR, SEM, XRD spectra, effective magnetic susceptibility measurements and thermogravimetric analysis (TGA).