Hoda El-Ghamry

Ni(II), Pd(II) and Pt(II) complexes of (1H-1,2,4-triazole-3- ylimino)methyl)naphthalene-2-ol. Structural, spectroscopic, biological, cytotoxicity, antioxidant and DNA binding

Metal complexes of the general formula [ML(H2O)Cl]nH2O; n=1 for M=Ni and Pt and n=2 for M=Pd, L=Schiff base (HL) derived from the condensation of 3-amino-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde, were prepared. The synthesized ligand and its metal complexes were characterized on the basis of elemental analyses, spectral and magnetic studies as well as thermal analysis. The IR spectra revealed that the ligand is coordinated to the metal ions in bidentate manner via the N-atom of the azomethine group and the phenolic OH group. Square planar geometry was proposed for Pd(II) and Pt(II) complexes and tetrahedral for Ni(II) complex. The ligand and its metal complexes were screened against the sensitive organisms Escherichia coli as Gram-negative bacteria, Staphylococcus aureus as Gram-positive bacteria, Aspergillus flavus and Candida albicans as fungi. Moreover, the anticancer activity of the ligand and its metal complexes was evaluated in liver carcinoma (HEPG2) cell line. The results obtained indicated that the Schiff base ligand is more effective than its metal complexes towards the tested cell line. Ni(II), Pd(II) and Pt(II) complexes as well as the free Schiff base ligand were tested for their antioxidant activities. The DNA-binding properties of the studied complexes have been investigated by electronic absorption and viscosity measurements.

Synthesis and characterization of Cu(II), Co(II) and Ni(II) complexes of a number of sulfadrug azodyes and their application for wastewater treatment

The azodye ligand (HL(1)) was synthesized from the coupling of sulfaguanidine diazonium salt with 2,4-dihydroxy-benzaldehyde while the two ligands, HL(2) and HL(3), were prepared by the coupling of sulfadiazine diazonium salt with salicylaldehyde (HL(2)) and 2,4-dihydroxy-benzaldehyde (HL(3)). The prepared ligands were characterized by elemental analysis, IR, (1)H NMR and mass spectra. Cu(II), Co(II) and Ni(II) complexes of the prepared ligands have been synthesized and characterized by various spectroscopic techniques like IR, UV-Visible as well as magnetic and thermal (TG and DTA) measurements. It was found that all the ligands behave as a monobasic bidentate which coordinated to the metal center through the azo nitrogen and α-hydroxy oxygen atoms in the case of HL(1) and HL(3). HL(2) coordinated to the metal center through sulfonamide oxygen and pyrimidine nitrogen. The applications of the prepared complexes in the oxidative degradation of indigo carmine dye exhibited good catalytic activity in the presence of H2O2 as an oxidant. The reactions followed first-order kinetics and the rate constants were determined. The degradation reaction involved the catalytic action of the azo-dye complexes toward H2O2 decomposition, which can lead to the generation of HO radicals as a highly efficient oxidant attacking the target dye. The detailed kinetic studies and the mechanism of these catalytic reactions are under consideration in our group.

Application of montmorillonite–Cu(II)ethylenediamine catalyst for the decolorization of Chromotrope 2R with H2O2 in aqueous solution

The kinetics of decolorization of Chromotrope 2R (C2R) was studied spectrophotometrically using the montmorilloniteK10-Cu(II)ethylenediamine composite (MMTK10-Cu(en)2) as catalyst and H2O2 as oxidant in aqueous solution. The catalyst was prepared and characterized by SEM, FTIR, XRD and TGA techniques. The dependence of reaction rate on H2O2 concentration was examined under UV irradiation in the presence and absence of the catalyst, and in the presence of the catalyst without the UV irradiation. In all these reaction systems, the rate increased up to a maximum value and then decreased. The rate increased with increasing the concentration of the dye reaching a maximum. Also, the rate of decolorization reaction showed a significant increase with increasing the amount of the catalyst and temperature. The addition of NaCl to the reaction medium has accelerated the rate effectively. A similar catalyst, MMTKSF-Cu(en)2, has also been employed and was found to be less efficient compared with MMTK10-Cu(en)2.

Synthesis, spectroscopic and DNA binding ability of Co II , Ni II , Cu II and Zn II complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex

A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L)2]·l2H2O, [Ni(L)Cl·(H2O)2].5H2O, [Cu(L)Cl] and [Zn(L)(CH3COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, 1H &13C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (Kb).

Synthesis and characterization of self-assembled coordination polymers of N-diaminomethylene-4-(3-formyl-4-hydroxy-phenylazo)-benzenesulfonamide

The azo dye ligand N-diaminomethylene-4-(3-formyl-4-hydroxy-phenylazo)-benzenesulfonamide (HL) and Cu(II), Co(II), and Mn(II) coordination polymers were synthesized in addition to a non-polymeric Pd(II) complex. In all complexes, the ligand bonds to the metal ion through the formyl and α-hydroxy oxygen atoms. The sulfonamide oxygen also coordinates to the metal. The complexes are formulated as [ML2] n , where M = Cu(II), Co(II), and Mn(II), and [ML(Cl)(H2O)], where M = Pd(II). On the basis of spectral studies and magnetic susceptibility measurements, an octahedral geometry was assigned to Co(II) and Mn(II) complexes, tetragonally elongated octahedral geometry for Cu(II) complex, while the Pd(II) complex was found to be square planar. Crystallization of Cu(II) complex from DMF afforded single crystals of general formula {[Cu(L)2] · 3DMF} n (2). X-ray structural analysis of 2 revealed that each Cu(II) adopts elongated octahedral geometry affording 1-D chains. The chains are connected by hydrogen bonds, resulting in the formation of 2-D supramolecular assemblies. The crystal structure of HL has also been determined and discussed. Cyclic voltammetric behavior of the ligand and some complexes are also discussed.

4-[(3-Formyl-4-hydroxy-phen-yl)diazen-yl]-N-(pyrimidin-2-yl) benzene-sulfonamide

The title molecule, C17H13N5O4S, has a trans configuration with respect to the diazenyl (azo) group. The pyrimidine ring and the terminal benzene ring are inclined at angles of 89.38 (4) and 1.6 (6)°, respectively, with respect to the central benzene ring. The conformation of the molecule is in part stabilized by an intramolecular O—H⋯O hydrogen bond. In the crystal structure, molecules related through inversion centers form hydrogen-bonded dimers involving the sulfonamide N—H group and the N atom of the pyrimidine ring.

Hydrogen-bonded frameworks of propylenediamine-N,N′-diacetic acid Pt(II) complexes, synthesis, structural characterization, and antitumor activity

Two Pt(II) complexes of propylenediamine-N,N′-diacetic acid (H2pdda) have been synthesized in which H2pdda is bidentate and tetradentate. The two complexes, [Pt(C7H14N2O4)Cl2] (1) and [Pt(C7H12N2O4)] (2), have been characterized by elemental analysis, IR, mass spectroscopy, and thermal (TGA and DTG) analysis. The crystal structure of 1 and [Pt(C7H12N2O4)]·3H2O (2a) are reported. In vitro cytotoxic properties of 1 and 2 were evaluated against HEPG2 (liver carcinoma cell lines) and HCT116 (colon carcinoma cell lines), and were compared with the standard anticancer drugs cisplatin (cis-DDP) and doxorubicin (Dox). The obtained data indicate that the two complexes show weak cytotoxic activity against the two tested cell lines, except for 1 which revealed a relatively high activity against HEPG2. Structure–activity relationships have been interpreted. Graphical Abstract

Synthesis, spectroscopic, thermal and molecular modeling studies of Zn 2 + , Cd 2 + and UO 2 2 + complexes of Schiff bases containing triazole moiety. Antimicrobial, anticancer, antioxidant and DNA binding studies

A novel series of Zn2+, Cd2+ and UO22+ complexes of ligands namely 1-[(5-mercapto-1H-1,2,4-triazole-3-ylimino) methyl]naphthalene-2-ol (HL1) and [(1H-1,2,4-triazole-3-ylimino) methyl] naphthalene-2-ol (HL2) have been prepared and characterized by different analytical and spectral techniques. The stoichiometry, stereochemistry, conductivity measurements and mode of bonding of the complexes have been elucidated. Accurate comparison of the IR spectra of the ligands with their metal chelates proved the involvement of nitrogen atoms of the azomethine group and/or triazole ring in chelation in addition to the deprotonated hydroxyl oxygen. The UV-Vis and molar conductance data supported the octahedral geometry for the metal complexes. TGA technique has been used to study the thermal decomposition way of the metal complexes and the thermo kinetic parameters were estimated. Valuable information is obtained from calculations of molecular parameters using the molecular modeling techniques. The interaction between the metal complexes and CT-DNA has been studied from which the binding constants (kb) were calculated. The Schiff bases and their metal chelates have shown potent antimicrobial, antioxidant and antitumor activities. The antitumor activities of the compounds have been tested in vitro against HEPG2 cell line and in silico by the molecular docking analysis with the VEGFR-2 receptor responsible for angiogenesis.

Dibromido(2,3,9,10-tetra­methyl-1,4,8,11-tetra­azacyclo­tetra­deca-1,3,8,10-tetra­ene)cobalt(III) bromide

In the title compound, [CoBr2(C14H24N4)]·Br, the CoIII ion is located on an inversion centre and possesses a distorted octahedral coordination geometry in which four nitrogen donors of the ligand molecule are in the equatorial plane and two Br− ions occupy both the axial sites to give a trans isomer. The Br- counter- anion is also located on an inversion centre.

1-[4-(Diamino­methyl­eneamino­sulfon­yl)phenyl­iminiometh­yl]-2-naphtholate N,N-dimethyl­formamide disolvate

The asymmetric unit the title compound, C18H16N4O3S·2C3H7NO, contains a molecule in a zwitterionic form with a deprotonated hydroxyl group and an iminium group, and two dimethylformamide solvent molecules. The dihedral angles of the guanidine group and the naphthyl ring system with respect to the central benzene ring are 76.04 (7) and 3.45 (9)°, respectively. The conformation of the molecule may be influenced, in part, by two intramolecular hydrogen bonds, while in the crystal structure, intermolecular hydrogen bonds form one-dimensional chains along [010].