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1.
Mater Sci Eng C Mater Biol Appl ; 103: 109727, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31349456

RESUMEN

The Cu2+, Co2+, Ni2+ and UO22+ polymer complexes of 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-8-hydroxyquinoline (HL) ligand were prepared and characterized. Elemental analyses, IR spectra, X-ray diffraction analysis and thermal analysis studies have been used to confirm the structure of the prepared polymer complexes. The chemical structure of metal chelates commensurate that the ligand acts as a neutral bis(bidentate) by through four sites of coordination (azo dye nitrogen, carbonyl oxygen, phenolic oxygen and hetero nitrogen from pyridine ring). The molecular and electronic structures of the hydrogen bond conformers of HL ligand were optimized theoretically and the quantum chemical parameters were calculated. Elemental analysis data suggested that the polymer complexes have composition of octahedral geometry for all the polymer complexes. Molecular docking of the binding between HL and the receptors of prostate cancer (PDB code 2Q7L Hormone) and the breast cancer (PDB code 1JNX Gene regulation) was studied. The interaction between HL and its polymer complexes with the calf thymus DNA (CT-DNA) was determined by absorption spectra. The antimicrobial activity of HL and its Cu2+, Co2+, Ni2+ and UO22+ polymer complexes were investigated; only Cu(II) polymer complex (1) was specifically active against Aspergillus niger. It inhibited the fungal sporulation and distorted the fungal mycelia, which became squashed at a concentration of 150 µg/ml; transmission electron microscope (TEM) also showed a deactivation of autophagy in the treated A. niger cells via accumulation of autophagic bodies in vacuoles. The inhibition process of the prepared ligand (HL) against the corrosion of carbon steel in 2 M HCl solution was determined by various methods (weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques) are found to be in reasonable agreement. The mechanism of inhibition in presence of HL in carbon steel corrosion obeys Friendlish adsorption isotherm.


Asunto(s)
Antiinfecciosos , Antineoplásicos , Complejos de Coordinación , Polímeros , Quinolinas , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Aspergillus niger/crecimiento & desarrollo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Corrosión , ADN/química , ADN/farmacología , Femenino , Humanos , Masculino , Simulación del Acoplamiento Molecular , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismo , Polímeros/química , Polímeros/farmacología , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Quinolinas/química , Quinolinas/farmacología , Receptores de Superficie Celular/antagonistas & inhibidores , Receptores de Superficie Celular/metabolismo
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 147: 200-11, 2015 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-25841152

RESUMEN

5-(2,3-Dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) and its metal complexes with copper(II) (1), cobalt(II) (2) and nickel(II) (3) are synthesized and characterized by physico-chemical techniques. The thermal properties of the ligand (HL) and its metal complexes (1-3) are discussed. The thermal activation energies of decomposition (Ea) of HL and its metal complexes with Cu(II), Co(II) and Ni(II) are found to be 48.76, 36.83, 30.59 and 40.45 kJ/mol, respectively. The frequency and temperature dependence of ac conductivity, dielectric constants for HL and its complexes (1-3) are investigated in the temperature range 300-356 K and frequency range 0.1-100 kHz. Both of the ac conductivity and the values of the thermal activation energy for conduction, as well as the dielectric properties of the complexes of HL are found to depend on the nature of the metallic ions. The values of the thermal activation energies of electrical conductivity decrease with increasing the value of test frequency. The small polarons tunneling (SPT) is the dominant conduction mechanism for the ligand (HL), while for complex (2) the overlapping large tunneling model (OLPT) is the dominant conduction mechanism. The correlated barrier hopping (CBH) is the dominant conduction mechanism for both of the complexes (1) and (3).

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 143: 200-12, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25727297

RESUMEN

A novel series of (5-(4'-derivatives phenyl azo)-8-hydroxy-7-quinolinecarboxaldehyde) (AQLn) (n=1, p-OCH3; n=2, R=H; and n=3; p-NO2) and their complexes [Cu(AQLn)2]·5H2O are synthesized and investigated. The optimized bond lengths, bond angles and the calculated quantum chemical parameters for AQLn are investigated. HOMO-LUMO energy gap, absolute electronegativities, chemical potentials, and absolute hardness are also calculated. The thermal properties, dielectric properties, alternating current conductivity (σac) and conduction mechanism are investigated in the frequency range 0.1-100kHz and temperature range 293-568K for AQL1-3 and 318-693K for [Cu(AQL1-3)2]·5H2O complexes. The thermal properties are of ligands (AQLn) and their Cu(II) complexes investigated by thermogravimetric analysis (TGA). The temperature and frequency dependence of the real and the imaginary part of the dielectric constant are studied. The values of the thermal activation energy of conduction mechanism for AQLn and their complexes [Cu(AQLn)2]·5H2O under investigation are calculated at different test frequencies. The values of thermal activation energies ΔE1 and ΔE2 for AQLn and [Cu(AQLn)2]·5H2O decrease with increasing the values of frequency. The ac conductivity is found to be depending on the chemical structure of the compounds. Different conduction mechanisms have been proposed to explain the obtained experimental data. The small polaron tunneling (SPT) is the dominant conduction mechanism for AQL1 and its complex [Cu(AQL1)2]·5H2O. The quantum mechanical tunneling (QMT) is the dominant conduction mechanism for AQL2 and its complex [Cu(AQL2)2]·5H2O. The correlated barrier hopping (CBH) is the dominant conduction mechanism for AQL3 and its complex [Cu(AQL3)2]·5H2O, and the values of the maximum barrier height (Wm) are calculated.


Asunto(s)
Compuestos Azo/química , Quelantes/química , Complejos de Coordinación/química , Cobre/química , Quinolinas/química , Compuestos Azo/síntesis química , Quelantes/síntesis química , Complejos de Coordinación/síntesis química , Conductividad Eléctrica , Modelos Moleculares , Teoría Cuántica , Quinolinas/síntesis química , Termodinámica , Termogravimetría
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 140: 111-31, 2015 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-25589393

RESUMEN

A number of novel polymer complexes of various anions of copper(II), cobalt(II), nickel(II) and uranyl(II) with N(4-(acrylamido)-2-hydroxy benzoic acid) (ABH) have been synthesized and characterized by elemental analysis, IR, 1H NMR, magnetic susceptibility measurements, electronic spin resonance, vibrational spectra and thermal analysis. The molecular structures of the ligand are optimized theoretically and the quantum chemical parameters are calculated. Tentative structures for the polymeric metal complexes due to their potential application are also suggested. The IR data exhibit the coordination of ONO2/OAc/SO4 with the metal ions in the polymeric metal complex. Vibrational spectra indicate coordination of carboxylate oxygen and phenolic OH of the ligand giving a MO4 square planar chromophore. Ligand field ESR spectra support square planar geometry around Cu(II). The thermal decomposition of the polymer complexes were discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated applying Coast-Redfern and Horowitz-Metzger methods.


Asunto(s)
Acrilamidas/química , Ácido Salicílico/química , Acrilamidas/síntesis química , Espectroscopía de Resonancia por Spin del Electrón , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Ácido Salicílico/síntesis química , Termodinámica , Termogravimetría
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 137: 1039-49, 2015 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-25286116

RESUMEN

N-acryloyl-4-aminosalicylic acid (4-AMSA), monomer (HL) and 5-(4'-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are synthesized and characterized with various physico-chemical techniques. Thin films of 5-(4'-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are prepared by spin coating technique. The X-ray diffraction (XRD) patterns of 4-aminosalicylic acid (4-ASA) and its derivatives are investigated in powder and thin film forms. Thermal properties of the compounds are investigated by thermogravemetric analysis (TGA). The optical energy gap and the type of optical transition are investigated in the wavelength range (200-2500 nm) for 4-ASA, HL and HLn. The values of fundamental energy gap (Eg) are in the range 3.60-3.69 eV for all compounds and the type of optical transition is found to be indirect allowed. The onset energy gap Eg(∗) appeared only for azodye compounds is found to be in the range 0.95-1.55 eV depending on the substituent function groups. The refractive index, n, shows a normal dispersion in the wavelength range 650-2500 nm, while shows anomalous dispersion in the wavelength rang 200-650 nm. The dispersion parameters ε∞, εL, Ed, Eo and N/m(∗) are calculated. The photoluminescence phenomena (PL) appear for thin films of 4-ASA and its derivatives show three main emission transitions.


Asunto(s)
Compuestos Azo/química , Membranas Artificiales , Salicilatos/química , Difracción de Rayos X
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 135: 774-91, 2015 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-25150428

RESUMEN

An interesting azodye heterocyclic ligand of copper(II), cobalt(II), nickel(II) and uranyl(II) complexes have been synthesized by the reaction of metal salts with 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)H and (13)C NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structures of the ligand tautomers are optimized theoretically and the quantum chemical parameters are calculated. The IR spectra showed that the ligand (HL) act as monobasic tridentate/neutral bidentate through the (-N=N), enolic (C-O)(-) and/or oxygen keto moiety groups forming a five/six-membered structures. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in dxy orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry is five/six-coordinated trigonal bipyramidal for complex (1) and octahedral for complexes (2-6). The value of covalency factor ß1(2) and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. The synthesized ligand (HL) and its Cu(II) complexes (1, 2 and 4) are screened for their biological activity against bacterial and fungal species. The ligand (HL) showed antimicrobial activities against Escherichia coli. The ligand (HL) and its Cu(II) complexes (2 and 4) have very high antifungal activity against Penicillium italicum. The inhibitive action of ligand (HL), against the corrosion of C-steel in 2M HCl solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).


Asunto(s)
Compuestos Azo/química , Colorantes/química , Metales/química , Temperatura , Compuestos Azo/farmacología , Bacterias/efectos de los fármacos , Espectroscopía de Resonancia Magnética con Carbono-13 , Colorantes/farmacología , Espectroscopía Dieléctrica , Espectroscopía de Resonancia por Spin del Electrón , Electrones , Hongos/efectos de los fármacos , Iones , Cinética , Ligandos , Fenómenos Magnéticos , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Espectroscopía de Protones por Resonancia Magnética , Pirazoles/química , Teoría Cuántica , Espectrofotometría Infrarroja , Marcadores de Spin , Estereoisomerismo , Termogravimetría , Difracción de Rayos X
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 127: 310-28, 2014 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-24632240

RESUMEN

A series of heterocyclic ligand of copper(II) complexes have been synthesized by the reaction of copper(II) acetate with 5-(4'-derivatives phenylazo)-2-thioxothiazolidin-4-one (HLn) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, spectral (IR and ESR), conductance, magnetic measurements, and thermogravimetric analysis (TGA) are used to characterize the isolated complexes. It is found that the change of substituent affects the thermal properties of azodye rhodanine derivatives and their Cu(II) complexes. The molecular and electronic structures of the investigated compounds (HLn) were also studied using quantum chemical calculations. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The data revealed that the coordination geometry around Cu(II) in all complexes (1-4) exhibit a trans square planar by NO monobasic bidentate and the two monobasic bidentate in octahedral complexes (5-7). Electronic, magnetic data and ESR spectra proposed the square planar structure for all complexes (1-4) under investigation. The value of covalency factor [Formula: see text] and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH(*)), entropy (ΔS(*)), and Gibbs free energy change of the decomposition (ΔG(*)) are calculated using Coats-Redfern and Horowitz-Metzger methods.


Asunto(s)
Cobre/química , Compuestos Heterocíclicos con 2 Anillos/química , Estructura Molecular , Termodinámica
8.
Artículo en Inglés | MEDLINE | ID: mdl-23973590

RESUMEN

A series of novel bidentate azodye quinoline ligands were synthesized with various p-aromatic amines like p-(OCH3, CH3, H, Cl and NO2). All ligands and their complexes have been characterized on the basis of elemental analysis, IR, (1)H and (13)C NMR data and spectroscopic studies. IR and (1)H NMR studies reveal that the ligands (HLn) exists in the tautomeric azo/hydrazo form in both states with intramolecular hydrogen bonding. The ligands obtained contain NN and phenolic functional groups in different positions with respect to the quinoline group. IR spectra show that the azo compounds (HLn) act as monobasic bidentate ligand by coordinating via the azodye (NN) and oxygen atom of the phenolic group. The ESR (g|| and g ) and bonding α(2) parameters of the copper ion were greatly affected by substituting several groups position of ring of quinoline and p-aromatic ring. The ESR spectra of copper complexes in powder form show a broad signal with values in order g|| >g > ge > 2.0023. The value of covalency factor ß and orbital reduction factor K accounts for the covalent nature of the complexes. All complexes possessed an octahedral and square planar geometry. The thermal properties of the complexes were investigated using TGA and DSC. It is found that the change of substituent affects the thermal properties of complexes.


Asunto(s)
Compuestos Azo/química , Colorantes/química , Cobre/química , Quinolinas/química , Espectroscopía de Resonancia por Spin del Electrón , Enlace de Hidrógeno , Ligandos , Espectrofotometría Infrarroja
9.
Artículo en Inglés | MEDLINE | ID: mdl-23268204

RESUMEN

A novel series of copper(II) and palladium(II) with 4-derivatives benzaldehyde pyrazolone (L(n)) were synthesized. The mixed ligand complexes were prepared by using 1,10-phenanthroline (Phen) as second ligand. The structure of these complexes was identified and confirm by elemental analysis, molar conductivity, UV-Vis, IR and (1)H NMR spectroscopy and magnetic moment measurements as well as thermal analysis. The ligand behaves as a neutral bidentate ligand through ON donor sites. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]Cl(2)⋅2H(2)O. Schiff bases (L(n)) were tested against bacterial species; namely two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and fungal species (Aspergillus niger, Fusarium oxysporium, Penicillium italicum and Alternaria alternata). The tested compounds have antibacterial activity against S. aureus, B. cereus and K. pneumoniae.


Asunto(s)
Antiinfecciosos/farmacología , Ampirona/química , Ampirona/farmacología , Antibacterianos/farmacología , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Cobre/química , Cobre/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Electrones , Hongos/efectos de los fármacos , Ligandos , Fenómenos Magnéticos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Paladio/química , Bases de Schiff/síntesis química , Bases de Schiff/química , Bases de Schiff/farmacología , Espectrofotometría Infrarroja , Termogravimetría , Difracción de Rayos X
10.
Artículo en Inglés | MEDLINE | ID: mdl-23036937

RESUMEN

A novel method to synthesize some mononuclear ternary palladium(II) complexes of the general formula [Pd(L(n))L] (where LH=diketone=acetylacetone, HL(n)=azorhodanine) has been synthesize. The structure of the new mononuclear ternary palladium(II) complexes was characterized using elemental analysis, spectral (electronic, infrared and (1)H &(13)C NMR) studies, magnetic susceptibility measurements and thermal studies. The IR showed that the ligands (HL(n) & LH) act as monobasic bidentate through the azodye nitrogen, oxygen keto moiety and two enolato oxygen atoms. The molar conductivities show that all the complexes are non-electrolytes. Bidentate chelating nature of ß-diketone and azorhodanine anions in the complexes was characterized by (electronic, infrared and (1)H &(13)C NMR) spectra. Square planar geometry around palladium has been assigned in all complexes. Various ligand and nephelouxetic parameter have been calculated for the complexes. The thermal decomposition for complexes was studied.


Asunto(s)
Compuestos Azo/química , Complejos de Coordinación/química , Paladio/química , Pentanonas/química , Rodanina/análogos & derivados , Compuestos Azo/síntesis química , Quelantes/síntesis química , Quelantes/química , Complejos de Coordinación/síntesis química , Ligandos , Espectroscopía de Resonancia Magnética , Pentanonas/síntesis química , Rodanina/síntesis química , Espectrofotometría Infrarroja
11.
Artículo en Inglés | MEDLINE | ID: mdl-23064551

RESUMEN

A novel series of platinum(II) and palladium(II) complexes have been synthesized by template condensation of 4-methoxybenzaldehyde, benzaldehyde, 4-chlorobenzaldehyde and 4-nitrobenzaldehyde, with appropriate 4-aminoantipyrine (4-AAP) in the presence of K(2)PtCl(4)/PdCl(2) to form complexes of the type [M(L(n))Cl(2)](where M=Pt(II) or Pd(II)). The corresponding Schiff base complexes mixed ligand were prepared by condensation of [M(L(n))Cl(2)] with ethanolamine (LH). The complexes have been characterized with the help of elemental analysis, IR, (1)H and (13)C NMR, electronic spectra, conductance measurements, magnetic susceptibilities and thermal analysis. On the basis of these studies, it is clear that ligands coordinated to metal atom in a mononuclear (NO) in (1-6), Schiff base complexes (NN(*)) in (7-9) and monobasic tridentate Schiff base complexes (NN(*)O) in (10-12). Thus, suitable square planar geometry for tetradentated state has been suggested for the metal complexes. Various ligand and nephelouxetic parameter have been calculated for the complexes. The thermal decomposition for complexes was studied.


Asunto(s)
Ampirona/química , Benzaldehídos/química , Complejos de Coordinación/química , Compuestos Organoplatinos/química , Paladio/química , Ampirona/síntesis química , Benzaldehídos/síntesis química , Complejos de Coordinación/síntesis química , Ligandos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Compuestos Organoplatinos/síntesis química , Bases de Schiff/síntesis química , Bases de Schiff/química , Espectrofotometría Infrarroja , Termogravimetría
12.
Artículo en Inglés | MEDLINE | ID: mdl-22137746

RESUMEN

The amidation of aliphatic amine with acryloyl chloride in dry benzene as a solvent has been performed. Moreover, the polymer complexes have been prepared and structurally characterized by analyses, molar conductance measurements, magnetic susceptibility measurements, spectral techniques like IR, UV, NMR, ESR and thermal methods. Acryloyl hydrazine (AH) has been shown to behave as a bidentate ligand via its nitrogen (NH(2) of hydrazine group) and C-O/C=O (acryloyl group) in polymer complexes, all of which exhibit supramolecular architectures assembled through weak interaction including hydrogen bonding and π-π stacking .The magnetic and spectral data indicate a square planar geometry for Cu(2+) complexes and an octahedral geometry for Co(II) and UO(2)(II). The ESR spectral data of the Cu(II) complexes showed that the metal-ligand bonds have considerable covalent character. The thermal stability was investigated using thermogravimetric analysis. The results showed that the polymer complexes are more stable than the homopolymer.


Asunto(s)
Sustancias Macromoleculares/química , Modelos Químicos , Polímeros/química , Complejos de Coordinación/química , Análisis Diferencial Térmico , Conductividad Eléctrica , Espectroscopía de Resonancia por Spin del Electrón , Electrones , Hidrazinas/química , Enlace de Hidrógeno , Ligandos , Espectroscopía de Resonancia Magnética , Magnetismo , Espectrofotometría Infrarroja , Estereoisomerismo , Temperatura , Termogravimetría , Vibración
13.
Artículo en Inglés | MEDLINE | ID: mdl-21962380

RESUMEN

The synthetic methods of novel Cu(II) and adduct complexes, with selective azodyes containing nitrogen and oxygen donor ligands have been developed, characterized and presented. The prepared complexes fall into the stoichiometric formulae of [Cu(L(n))(2)](A) and [Cu(L(n))(2)(Py)(2)](B), where two types of complexes were expected and described. In type [(A) (1:2)] the chelate rings are six-membered/four coordinate, whereas in type [(B) (1:2:2)] they are six-membered/six coordinate. The important bands in the IR spectra and main (1)H NMR signals are tentatively assigned and discussed in relation to the predicted assembly of the molecular structure. The IR data of the azodye ligands suggested the existing of a bidentate binding involving azodye nitrogen and C-O oxygen atom of enolic group. They also showed the presence of Py coordinating with the metal ion. The coordination geometries and electronic structures are determined from the framework of the proposed modeling of the formed novel complexes. The complexes (1-5) exist in trans-isomeric [N,O] solid form, while adduct complexes (6-10) exist in trans isomeric (Py) form. The square planar/octahedral coordination geometry of Cu(II)/adduct is made up of an N-atom of azodye, the deprotonated enolic O-atom and two Py. The azo group was involved in chelation for all the prepared complexes. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]. The ligands in the dimmer are stacked over one another. In the solid state of azo-rhodanine, the dimmers have inter- and intramolecular hydrogen bonds. Interactions between the ligands and Cu(II) are also discussed.


Asunto(s)
Compuestos Azo/química , Colorantes/química , Complejos de Coordinación/química , Cobre/química , Espectroscopía de Resonancia por Spin del Electrón , Enlace de Hidrógeno , Espectroscopía de Resonancia Magnética
14.
Artículo en Inglés | MEDLINE | ID: mdl-21906992

RESUMEN

Supramolecular coordination of dioxouranium(VI) heterochelates 5-sulphono-7-(4'-X phenylazo)-8-hydroxyquinoline HL(n) (n=1, X=CH(3); n=2, X=H; n=3, X=Cl; n=4, X=NO(2)) have been prepared and characterized with various physico-chemical techniques. The infrared spectral studies showed a monobasic bidentate behavior with the oxygen and azonitrogen donor system. The temperature dependence of the D.C. electrical conductivity of HL(n) ligands and their uranyl complexes has been studied in the temperature range 305-415 K. The thermal activation energies E(a) for HL(n) compounds were found to be in the range 0.44-0.9 eV depending on the nature of the substituent X. The complexation process decreased E(a) values to the range 0.043-045 eV. The electrical conduction mechanism has been investigated for all samples under investigation. It was found to obey the variable range hopping mechanism (VRH).


Asunto(s)
Óxidos/química , Oxiquinolina/química , Sulfonas/química , Uranio/química , Compuestos Azo/química , Conductividad Eléctrica , Ligandos , Conformación Molecular , Semiconductores , Espectrofotometría Infrarroja
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 79(5): 1057-62, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21632280

RESUMEN

N-(biphenylmethylidenyl) chitosan polymer was prepared, characterized and thermal stability was compared with chitosan. Thermal degradation products of the modified polymer were identified by GC-MS technique. It seems that the mechanism of degradation of the prepared polymer is characterized by formation of low molecular weight radicals, followed by random scission mechanism along the backbond chain.


Asunto(s)
Benzofenonas/química , Quitosano/química , Quitosano/metabolismo , Polímeros/química , Polímeros/metabolismo , Materiales Biocompatibles , Cromatografía de Gases y Espectrometría de Masas , Peso Molecular , Temperatura
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 78(3): 1119-25, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21227746

RESUMEN

Oxovanadium(IV) polymer complexes of formulation {[(VO)L](2)}(n) (1) and [(VO)LB](n) (2-4), where H(2)L is tridentate and dianionic ligand (allylazorhodanine) and B is planar heterocyclic and aliphatic base have been prepared and characterized by elemental analyses, IR, (1)H NMR, electronic spin resonance spectra, magnetic susceptibility measurements, molar conductance and thermal studies. The molecular structure shows the presence of a vanadyl group in six-coordinate VNO(3)/VN(3)O(3) coordination geometry. The N,N-donor heterocyclic and aliphatic bas displays a chelating mode of binding with an N-donor site trans to the vanadyl oxo-group. In all polymeric complexes (1-4) the ligand coordinates through oxygen of phenolic/enolic and azodye nitrogen. The molar conductivity data show them to be non-electrolytes. All the polymer complexes are ESR active due to the presence of an unpaired electron. The calculated bonding parameters indicate that in-plane σ bonding is more covalent than in-plane π bonding. From the electronic, magnetic and ESR spectral data suggest that all the oxovanadium(IV) polymer complexes have distorted octahedral geometry. The thermal decomposition process of the polymeric complexes involves three decomposition steps.


Asunto(s)
Quelantes/química , Polímeros/química , Vanadio/química , Espectroscopía de Resonancia por Spin del Electrón , Estructura Molecular , Análisis Espectral/métodos
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 77(4): 795-801, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20833100

RESUMEN

Novel polymer complexes of copper(II), palladium(II), platinum(II) and cadmium(II) containing homopolymer [4-acrylamido benzene sulphonyl guanidine; (HL)] and various anions (SO4²â», CH3COO⁻, NO3⁻, Br⁻ or Cl⁻) have been designed and carried out. Their structures were investigated by elemental analyses, spectral (IR, UV-vis, ¹H NMR and ESR) and magnetic moments. The modes of interactions between the ligand and the metals were discussed, where oxygen (of O=S=O group) and nitrogen atom [of imino nitrogen (NH/N) of the guanidine group] are involved in chelation. The homopolymer shows two types of coordination behaviour. In mononuclear polymer complexes 4 and 6-10, it acts as a neutral bidentate ligand chelated through the NH and O atoms, whereas in the polymer complexes 1-3, 5 and 11, monobasic bidentate ligand is coordinated through the -N and -O atoms. The poly-chelates are of 1:1/1:2 (metal-homopolymer) stoichiometry and exhibit four coordination. On the basis of electronic spectral data and magnetic susceptibility measurement square planar geometry has been proposed. The ESR spectral data provided information about their structure on the basis Hamiltonian parameters and degree of covalency. From the electron paramagnetic resonance and spectral data, the orbital reduction factors were calculated.


Asunto(s)
Complejos de Coordinación/química , Espectroscopía de Resonancia por Spin del Electrón , Guanidina/análogos & derivados , Polímeros/química , Guanidina/química , Ligandos , Metales Pesados/química , Estructura Molecular , Nitrógeno/química , Oxígeno/química , Azufre/química
18.
Artículo en Inglés | MEDLINE | ID: mdl-20692866

RESUMEN

A novel series of nickel(II) polymer complexes of 5-sulphadiazineazo-3-phenylamino-2-thio-4-thiazolidinone (HL1), 5-sulphamethazine-3-phenylamino-2-thioxo-4-thiazolidinone (HL2), 5-sulphamethoxazole-3-phenylamino-2-thioxo-4-thiazolidinone (HL3), 5-sulphacetamide-3-phenyl-2-thioxo-4-thiazolidinone (HL4) and 5-sulphaguanidine-3-phenylamino-2-thioxo-4-thiazolidinone (HL5) were prepared and characterized. IR spectra show that HL(n) (n=1-5) is coordinated to the metal ion in a neutral tetradentate manner with NSNO donor sites of NH (hydrazone's), NH (3-phenylamine), carbonyl group and Ph-NH. The title [Ni3(HL(n))2(µ-OAc)2(OAc)4](n) consists of three Ni(II) atoms linked by interchain π-π interaction are observed between aromatic rings of two ligands (HL(n)) which are further doubly bridged two adjacent nickel atoms by acetate group. The geometrical structures of these complexes are found to be octahedral. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, thermal, infrared, ¹H NMR, electronic spectra, magnetic susceptibility and conductivity measurements. The richness of electronic spectral in these complexes is also supporting evidence for the trinuclearity of the Ni(II) polymer complexes.


Asunto(s)
Electrones , Enlace de Hidrógeno , Níquel/química , Polímeros/química , Ligandos , Metales , Estructura Molecular , Donantes de Óxido Nítrico/química , Análisis Espectral , Azufre/química
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 75(1): 394-405, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19944640

RESUMEN

Novel five binuclear polymeric dioxouranium(VI) of azosulphadrugs [(azodrug substances) azobenzene sulphonamides] were prepared for the first time. The infrared spectra of the samples were recorded and their fundamental vibration wave number was obtained. The resulting polymeric uranyl complexes were characterized on the basis of their elemental analyses, conductance and spectral (IR, NMR, and electronic spectra) data. The ligation modes of the azosulphadrugs ligands towards uranyl(II) ions were critically assigned and addressed properly on the basis of their IR and their uranyl(II) complexes. The theoretical aspects are described in terms of the well-known theory of 5d-4f transitions. The coordination geometries and electronic structures are determined from a framework for the modeling of novel polymer complexes. The values of nu(3) of the prepared complexes containing UO(2)(2+) were successfully used to calculate the force constant, F(UO) (1n 10(-8)N/A) and the bond length R(UO) of the U-O bond. Wilson's, matrix method, Badger's formula, and Jones and El-Sonbati equations were used to calculate the U-O bond distances from the values of the stretching and interaction force constants. The most probable correlations between U-O force constant to U-O bond distance were satisfactorily discussed in terms of "Badger's rule", "Jones" and "El-Sonbati equations".


Asunto(s)
Compuestos Azo/química , Hidrazonas/química , Polímeros/química , Sulfonamidas/química , Compuestos de Uranio/química , Compuestos Azo/síntesis química , Hidrazonas/síntesis química , Estructura Molecular , Polímeros/síntesis química , Análisis Espectral/métodos , Sulfonamidas/síntesis química , Tiazolidinas/síntesis química , Tiazolidinas/química , Compuestos de Uranio/síntesis química
20.
Artículo en Inglés | MEDLINE | ID: mdl-12524114

RESUMEN

The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [(11)+(12)] in the paper and in mononuclear polymer complexes (1)-(5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX2 and KPtCl4 in the presence of N-heterocyclic base consisting of polymer complexes (9)+(10), and in monouclear compounds (6)-(8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds (13)+(14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.


Asunto(s)
Polímeros/química , Quelantes/síntesis química , Quelantes/química , Fenómenos Químicos , Química Física , Electroquímica , Ligandos , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/química , Paladio/química , Platino (Metal)/química , Polímeros/síntesis química , Rodio/química , Rutenio/química , Espectrofotometría Infrarroja
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