Moamen S. Refat

Spectroscopic, thermal and antitumor investigations of sulfasalazine drug in situ complexation with alkaline earth metal ions

The complexes of sulfasalazine (H(3)Suz) with some of alkaline metals Mg(II), Ca(II), Sr(II) and Ba(II) have been investigated. Sulfasalazine complexes were synthesized and characterized by spectroscopic tools; infrared spectra, electronic and mass spectra. The IR spectra of the prepared complexes were suggested that the H(3)Suz behaves as a bi-dentate ligand through the carboxylic and phenolic groups. The molar conductance measurements gave an idea about the non-electrolytic behavior of the H(3)Suz complexes. The thermal decomposition processes for metal(II) complexes of H(3)Suz viz: [M(HSuz)(H(2)O)(4)] (where M = Mg(II), Ca(II), Sr(II) or Ba(II)) have been accomplished on the basis of TG/DTG and DTA studies, and the formula conforms to the stoichiometry of the complexes based on elemental analysis. The kinetic analyses of the thermal decomposition were studied using the Coats-Redfern and Horowitz-Metzger equations. The antitumor and antimicrobial activities of the H(3)Suz and their alkaline metal(II) complexes were evaluated.

Novel charge-transfer complexes of 4-hexylamino-1,8-naphthalimide-labelled PAMAM dendrimer with some acceptors: a spectrophotometric study

Poly(amidoamine) dendrimers are very interesting macromolecules with highly branched structures and globular-shaped branched polymeric architectures. They are widely used for drug and gene delivery applications. In order to provide important insight into the interactions of poly(amidoamine) dendrimers with some organic acceptors, the binding of small molecules to 4-hexylamino-1,8-naphthalimide-labelled PAMAM dendrimer (PD) have been studied by spectrophotomeric method. The acceptors used in this research include chloranilic acid (CLA), p-chloranil (CHL), 2,6-dichloroquinone-4-chloroimide (DCQ), 2,6-dibromoquinone-4-chloroimide (DBQ), 7,7ʹ,8,8ʹ-tetracyanoquinodimethane (TCNQ), picric acid (PA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and iodine monobromide (IBr). The spectrophotometric measurements proved that all the charge-transfer (CT) complexes are formed via a stoichiometry (PD: acceptor) of 1:2 (except for IBr acceptor). Accordingly the obtained complexes could be formulated as [(PD)(CLA)2], [(PD)(DCQ)2], [(PD)(DBQ)2], [(PD)(TCNQ)2], [(PD)(PA)2], [(PD)(CHL)2], [(PD)(DDQ)2] and [(PD)(IBr)4]. Benesi–Hildebrand and its modification methods were applied to estimate the spectroscopic and physical data.

Synthesis and Characterization of Coordination Behavior of Diclofenac Sodium Drug Toward Hg(II), Pb(II), and Sn(II) Metal Ions: Chelation Effect on Their Thermal Stability and Biological Activity

Diclofenac sodium compound has great biological, medical, industrial, and coordination applications. Most of its metal complexes have antibacterial and antifungal effects. A general survey of previous literature concerning the interaction of transition metals with diclofenac compound was given. From this survey, it is appeared that deep chemical studies were needed to through lighter on the complexing ability and chemical properties, due to presence of active groups such as amino, hydroxyl, carbonyl, and carboxyl groups. Therefore the present work was aimed mainly to study the spectroscopic, stability, and related thermodynamic parameters, structural, thermal, molar conductivity, and biological properties of the diclofenac sodium with selected metal ions such as Hg(II), Pb(II), and Sn(II). The used of theoretical concepts and experimental techniques were discussed. Solid complexes have been prepared and characterized by IR, UV-Vis, elemental analysis CHN, and 1H-NMR. Diclofenac reacts with Hg(II), Pb(II), and Sn(II) by molar ratio (2:1) (diclofenac:metal ion). IR, UV-Vis, spectra indicate that diclofenac behaves as a monobasic bidentate ligand coordinated to the metal ions via the deprotonated carboxylate O and carbonyl groups. The Hg(II), Pb(II), and Sn(II) complexes of diclofenac are found to have high activity against bacteria, especially Bacillus subtilis, and fungi, especially Aspergillus niger, whereas the Pb(II) complex is more active than the Sn(II) and Hg(II) complexes.

A Series of Taurocholic Acid Complexes, Spectral, Kinetic, Molecular Modeling, and Antiviral Activity Studies

A series of taurocholic acid complexes was prepared with Cr(III), Fe(III), Co(II), Ni(II), and Cu(II) ions. The IR and Raman spectral data reveal the coordination of acid as mononegative bidentate. NH, and sulfonate (–O−). The bidentate mode of coordination is proposed toward all the metal ions. The electronic spectral data as well as the magnetic moment measurements proposed the octahedral geometry for all investigated complexes. The presence of water molecules was supported by thermal analysis study. ESR spectrum of Cu(II) complex was carried out and acting as a further supporting for the octahedral geometry. The molecular modeling was performed for all complexes to assert on the lower energy content for all isolated complexes in comparing with their free ligand. Such concludes the comparative stability of all isolated complexes. Scanning electron micrography for the Cu(II) complex reveals the particle size is presented in the nano range. An elaborated biological investigation was carried out for all complexes in comparison with their free ligand. The highest antiviral activity was observed with the free ligand and its Ni(II) and Co(II) complexes and moderate activity was observed with Cr(III) and Fe(III) complexes, but the lowest activity was observed with Cu(II) complex.

IR, Electronic, Thermal, Cyclic Voltammetric, and Computational Studies on Ferric(III) Albendazole Complex

Preparation, spectroscopic characterization, electrochemical studies, and theoretical calculations of albendazole (Albz) and its mononuclear ferric(III) complex, [Fe(Albz)(Cl)3(H2O)], are described. Based on infrared and electronic spectra as well as magnetic measurements Albz molecule seems to be a neutral bidentate ligand via carbonyl group and NH of five-member ring with octahedral fashion toward Fe(III) ions. The thermogravimetric analysis confirms the presence of water molecules existed inside the coordination sphere. The kinetic parameters were estimated and gave an idea about the stability of ferric(III)–Albz complex dependent of TG–DTG curves.

Charge transfer interaction of organic p-acceptors with the anti-hyperuricemic drug allopurinol: Insights from IR, Raman, 1H NMR and 13C NMR spectroscopies

Abstract The topic of charge-transfer (CT) complexation of vital drugs has attracted considerable attention in recent years owing to their significant physical and chemical properties. In this study, CT complexes derived from the reaction of the anti-hyperuricemic drug allopurinol (Allop) with organic p-acceptors [(picric acid (PA), dichlorodicyanobenzoquinone (DDQ) and chloranil (CHL)] were prepared, isolated and characterized by a range of physicochemical methods, such as IR, Raman, 1H NMR and 13C NMR spectroscopy. The stoichiometry of the complexes was verified by elemental analysis. The results show that all complexes that were formed were based on a 1:1 stoichiometric ratio. This study suggests that the complexation of Allop with either the DDQ or CHL acceptor leads to a direct p®p* transition, whereas the molecules of Allop and PA are linked by intermolecular hydrogen- bonding interactions.

Synthesis and Spectroscopic Characterization of Zr(IV) and Th(IV) With Chelating Containing ONNO Donor Quadridentate Schiff Bases Complexes

New metal complexes of novel Schiff bases derived from the reaction of zirconium (IV) and thorium (IV) ions with N,N′-disalicylidene-l,2-phenylenediamine (H2dsp), N,N′-disalicylidene-3,4-diaminotoluene (H2dst), 4-nitro-N,N-disalicylidene-1,2-phenylenediamine (H2ndsp) were prepared and characterized based on elemental analyses, IR and 1H NMR spectroscopy, molar conductance, and thermal analyses. The complexes are formed in 1:1 [Metal]:[Ligand] ratio. The molar conductance measurements proved that all these complexes are non-electrolytes. The IR spectra of the ligands and their complexes are used to identify the type of bonding. The thermogravimetric analysis of the complexes shows metal oxide remaining as the final product.

Microwave Synthesis of Copolymers Based on Itaconic Acid Moiety and Their Utility for Scavenging of Copper (II) and Lead (II)

We report here the preparation of the two copolymers, itaconic acid-methyl methacrylate and itaconic acid-acrylamide, in different ratios using microwave irradiation in the presence of azobisisobutyronitrile (AIBN) as initiator and 2-butanone as a solvent. All the prepared copolymers were characterized by different techniques; FT-IR, thermal analysis and elemental microanalysis. The thermal stability property of the prepared copolymers correlated with the changing of the itaconic acid ratio, as the ratio of itaconic acid increased, the crystallinity of the copolymer decreases. The itaconic acid-based copolymers also showed a good scavenging behavior in alkaline media for Cu (II) and Pb (II). The chelation behavior of both Cu (II) and Pb (II) complexes were checked using FT-IR, thermogravimetric analysis (TGA), and differential scanning calorimetery (DSC).

Soft chemistry synthesis, crystal structure and 3D-AFM-micro-structural surface features of calcium-barium selenate molecule with AB2X5 structure

Acetate-citrate precursors were applied to synthesize amorphous gelatinous calcium barium selenate with molecular formula (Ca0.5Ba0.5Se2O5). The gel-product was sintering at 800°C for 2 hrs then well characterized by X-ray diffraction, SEM and EDX elemental analyses and proved that the product Ca0.5Ba0.5Se2O5 is mainly belong to AB2X5-type structure with average grain size ranged in between 1.2–3.8 μm. A visualized study was constructed depending upon SEM and 3D-AFM experimental data to confirm the the microstructure morphological features of calcium-barium selenate surface.

Synthesis, Spectroscopic, Thermal, and Photostability Studies of 2-aminobenzaldehyde Phenylhydrazone (2ABPH) as Fluorescent Dye and their Cu(II), Co(II), and Mn(II) Complexes

Herein, the 2-aminobenzaldehyde phenylhydrazone (2ABPH) Schiff base and their mononuclear Mn(II), Co(II), and Cu(II) complexes were reported. The structures of the complexes have been elucidated by elemental analysis, molar conductivity, magnetic properties, infrared, electronic, mass spectra, and thermal studies. The stoichiometries of the 2ABPH complexes accordance of the mentioned analysis give the general formula [M(2ABPH)2(Cl)2].xH2O (where M is Mn(II), Co(II), Cu(II), and x = 1, 4 and 6). The photo stabilities of the Schiff base and their complexes were examined.