Simulation of the reaction of paracetamol in the presence of a diamine in the liver using an elec... more Simulation of the reaction of paracetamol in the presence of a diamine in the liver using an electrochemical cell.
A novel copper complex of proline‐based mono(phenol) amine (HLPro) immobilized in SBA‐15 as a mod... more A novel copper complex of proline‐based mono(phenol) amine (HLPro) immobilized in SBA‐15 as a model of Galactose oxidase enzyme has been synthesized and characterized using transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared (FT‐IR), N2 adsorption–desorption, thermogravimetric analysis (TGA), and elemental analysis. The immobilized complex was found to heterogeneously catalyse the aerobic oxidation of alcohols under mild conditions to the corresponding aldehydes in the presence of TEMPO and in the absence of any additive such as base. The catalyst was easily recovered by a simple filtration and was subsequently reused in the four reaction cycles without considerable loss of activity.
Abstract A new iron complex of bis(phenol) amine ligand of glycine amino acid derivative, FeLGDC ... more Abstract A new iron complex of bis(phenol) amine ligand of glycine amino acid derivative, FeLGDC supported on amine-functionalized graphene oxide (GO) nanosheets (FeLGDC -AP@GO) was synthesized. This is the first report of bis(phenol) amine complexes immobilized to a solid support. This novel catalyst was characterized by different techniques such as TEM, SEM, EDX, XRD, FT-IR, TGA, AAS, ICP-AES and Porosimetry. The results show that FeLGDC -AP@GO has layered structure incorporating FeLGDC complex by covalent attachment. FeLGDC-AP@GO was examined as a catalyst for the selective oxidation of sulfides as environmental pollutants to their corresponding sulfoxides. This reaction was performed using hydrogen peroxide as a green oxidant in water at room temperature. The recycling experiment results showed that FeLGDC -AP@GO could be easily recovered by simple filtration and recycled for several times without the loss of activity and selectivity.
The association behavior of tetrakis( N , N ′, N ″, N ‴-tetramethyl tetra-2,3-pyridino)porphyrazi... more The association behavior of tetrakis( N , N ′, N ″, N ‴-tetramethyl tetra-2,3-pyridino)porphyrazine copper(II) ([ Cu(II) 2,3- tmtppa ]4+) was investigated in aqueous solutions at 25 °C and various ionic strengths using optical absorption and resonance light scattering (RLS) spectroscopies. The results show that ([ Cu(II) 2,3- tmtppa ]4+) does not have any affinity for aggregation due to increasing of salt concentration and exists as monomers even in homogeneous aqueous solutions of high ionic strengths (more than 1 M NaCl ). Interaction of ([ Cu(II) 2,3- tmtppa ]4+) with calf thymus DNA has also been studied in 1 mM aqueous phosphate buffer of pH 7.0, by optical absorption and RLS spectroscopies, and thermal denaturation experiments. The appearance of hypochromicity of less than 10% and bathochromicity shift of Δλ ≤ 2 nm in UV-vis spectra of ([ Cu(II) 2,3- tmtppa ]4+), increasing of thermal melting point of DNA, and no change in RLS spectra of porphyrazine due to interaction with DN...
Journal of Porphyrins and Phthalocyanines, Nov 1, 2007
Interaction of N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatonickel(II), ([ Ni (2,... more Interaction of N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatonickel(II), ([ Ni (2,3- tmtppa )]4+) and N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatoiron(II), ([ Fe (2,3- tmtppa )]4+) with calf thymus DNA (CT-DNA) have been studied in 1mM phosphate buffer and low ionic strength (5 mM NaCl ) using several spectroscopic techniques: absorbance, fluorescence and circular dichroism. The 2:1 porphyrazine/DNA mole ratio, existence of moderate hypochromicity, moderate and progressive red shift and conservative ICD in the visible part of [ Fe (2,3- tmtppa )]4+ spectra suggested an outside binding with self-stacking mode. Analysis of the dramatic hypochromicity, small blue shift and bisignate ICD in the Q-band absorption region of [ Ni (2,3- tmtppa )]4+ spectra and 1:1 porphyrazine/DNA mole ratio possibly led us to the dual binding mode of this complex, i.e. at the minor and major grooves of DNA. The influence of the ionic strength on the porphyrazine-DNA binding confirmed this suggestion. The fluorescence quenching of DNA-ethidium bromide complex by porphyrazines was investigated. The values of quenching constants ( K sv ) and the rate constants of the quenching ( K q ) were determined by Stern-Volmer equation. The values of K sv have been obtained (2.07 ± 0.11) × 106 and (0.48 ± 0.01) × 106 M−1 for [ Fe (2,3- tmtppa )]4+ and [ Ni (2,3- tmtppa )]4+, respectively, at 27°C. The higher affinity of [ Fe (2,3- tmtppa )]4+ for the quenching of EB-DNA fluorescence with respect to Ni complex was attributed to self-stacking of the former along DNA helix and favorable energy transfer between EB+ and cationic porphyrazine. ΔG25 (the difference between the free energy of the native ( N ) and the denatured (D) form of DNA at 25°C), ΔHm and ΔSm (difference between enthalpy and entropy at Tm) were extracted from thermal curves. The decline in the melting temperature of DNA following the addition of porphyrazine complexes confirms that the substantial mode of Ni and Fe interaction is not intercalation. The thermodynamic results imply that both Ni and Fe complexes have a slight destabilizing effect on the DNA. A comparison between [ Ni ( tmtppa )]4+ and [ Fe ( tmtppa )]4+ indicates that the latter is more effective than the former.
Abstract An ethylene diamine derivative of a bis(phenol)diamine ligand (H2L) was synthesized via ... more Abstract An ethylene diamine derivative of a bis(phenol)diamine ligand (H2L) was synthesized via the Mannich reaction and subsequent ring cleavage of the produced imidazoline ring (H2LIm), and then it was characterized by 1H NMR and IR spectroscopies and CHN analysis. The iron(III) complex (FeLCl) of this ligand was synthesized and characterized by IR, UV–Vis, X-ray and magnetic susceptibility studies. X-ray analysis reveals that in FeLCl the iron(III) center has a distorted square pyramidal coordination sphere and is surrounded by a chlorine atom, two amine nitrogen and two phenolate oxygen atoms of the ligand. Variable-temperature magnetic susceptibility measurements indicate that FeLCl is a paramagnetic high spin iron(III) complex. It shows weak antiferromagnetic interactions through N H⋯Cl intermolecular interactions. The ligand-centered electrochemical oxidation of this complex, due to the oxidation of phenolate group to phenoxyl radicals, as well as the electrochemical metal-centered reduction of the ferric ion to the ferrous ion were investigated. In addition, the efficient cleavage by oxygenation of 3,5-di-tert-butyl-catechol with FeLCl in the presence of dioxygen was observed.
A ZnTCPP-TiO2/CoFe2O4 nanohybrid easily reusable using a permanent magnet without losing its reac... more A ZnTCPP-TiO2/CoFe2O4 nanohybrid easily reusable using a permanent magnet without losing its reactivity for the selective production of aldehydes from a mechanistic point of view.
Simulation of the reaction of paracetamol in the presence of a diamine in the liver using an elec... more Simulation of the reaction of paracetamol in the presence of a diamine in the liver using an electrochemical cell.
A novel copper complex of proline‐based mono(phenol) amine (HLPro) immobilized in SBA‐15 as a mod... more A novel copper complex of proline‐based mono(phenol) amine (HLPro) immobilized in SBA‐15 as a model of Galactose oxidase enzyme has been synthesized and characterized using transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared (FT‐IR), N2 adsorption–desorption, thermogravimetric analysis (TGA), and elemental analysis. The immobilized complex was found to heterogeneously catalyse the aerobic oxidation of alcohols under mild conditions to the corresponding aldehydes in the presence of TEMPO and in the absence of any additive such as base. The catalyst was easily recovered by a simple filtration and was subsequently reused in the four reaction cycles without considerable loss of activity.
Abstract A new iron complex of bis(phenol) amine ligand of glycine amino acid derivative, FeLGDC ... more Abstract A new iron complex of bis(phenol) amine ligand of glycine amino acid derivative, FeLGDC supported on amine-functionalized graphene oxide (GO) nanosheets (FeLGDC -AP@GO) was synthesized. This is the first report of bis(phenol) amine complexes immobilized to a solid support. This novel catalyst was characterized by different techniques such as TEM, SEM, EDX, XRD, FT-IR, TGA, AAS, ICP-AES and Porosimetry. The results show that FeLGDC -AP@GO has layered structure incorporating FeLGDC complex by covalent attachment. FeLGDC-AP@GO was examined as a catalyst for the selective oxidation of sulfides as environmental pollutants to their corresponding sulfoxides. This reaction was performed using hydrogen peroxide as a green oxidant in water at room temperature. The recycling experiment results showed that FeLGDC -AP@GO could be easily recovered by simple filtration and recycled for several times without the loss of activity and selectivity.
The association behavior of tetrakis( N , N ′, N ″, N ‴-tetramethyl tetra-2,3-pyridino)porphyrazi... more The association behavior of tetrakis( N , N ′, N ″, N ‴-tetramethyl tetra-2,3-pyridino)porphyrazine copper(II) ([ Cu(II) 2,3- tmtppa ]4+) was investigated in aqueous solutions at 25 °C and various ionic strengths using optical absorption and resonance light scattering (RLS) spectroscopies. The results show that ([ Cu(II) 2,3- tmtppa ]4+) does not have any affinity for aggregation due to increasing of salt concentration and exists as monomers even in homogeneous aqueous solutions of high ionic strengths (more than 1 M NaCl ). Interaction of ([ Cu(II) 2,3- tmtppa ]4+) with calf thymus DNA has also been studied in 1 mM aqueous phosphate buffer of pH 7.0, by optical absorption and RLS spectroscopies, and thermal denaturation experiments. The appearance of hypochromicity of less than 10% and bathochromicity shift of Δλ ≤ 2 nm in UV-vis spectra of ([ Cu(II) 2,3- tmtppa ]4+), increasing of thermal melting point of DNA, and no change in RLS spectra of porphyrazine due to interaction with DN...
Journal of Porphyrins and Phthalocyanines, Nov 1, 2007
Interaction of N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatonickel(II), ([ Ni (2,... more Interaction of N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatonickel(II), ([ Ni (2,3- tmtppa )]4+) and N , N ′, N ″, N ‴-tetramethyltetra-2,3-pyridinoporphyrazinatoiron(II), ([ Fe (2,3- tmtppa )]4+) with calf thymus DNA (CT-DNA) have been studied in 1mM phosphate buffer and low ionic strength (5 mM NaCl ) using several spectroscopic techniques: absorbance, fluorescence and circular dichroism. The 2:1 porphyrazine/DNA mole ratio, existence of moderate hypochromicity, moderate and progressive red shift and conservative ICD in the visible part of [ Fe (2,3- tmtppa )]4+ spectra suggested an outside binding with self-stacking mode. Analysis of the dramatic hypochromicity, small blue shift and bisignate ICD in the Q-band absorption region of [ Ni (2,3- tmtppa )]4+ spectra and 1:1 porphyrazine/DNA mole ratio possibly led us to the dual binding mode of this complex, i.e. at the minor and major grooves of DNA. The influence of the ionic strength on the porphyrazine-DNA binding confirmed this suggestion. The fluorescence quenching of DNA-ethidium bromide complex by porphyrazines was investigated. The values of quenching constants ( K sv ) and the rate constants of the quenching ( K q ) were determined by Stern-Volmer equation. The values of K sv have been obtained (2.07 ± 0.11) × 106 and (0.48 ± 0.01) × 106 M−1 for [ Fe (2,3- tmtppa )]4+ and [ Ni (2,3- tmtppa )]4+, respectively, at 27°C. The higher affinity of [ Fe (2,3- tmtppa )]4+ for the quenching of EB-DNA fluorescence with respect to Ni complex was attributed to self-stacking of the former along DNA helix and favorable energy transfer between EB+ and cationic porphyrazine. ΔG25 (the difference between the free energy of the native ( N ) and the denatured (D) form of DNA at 25°C), ΔHm and ΔSm (difference between enthalpy and entropy at Tm) were extracted from thermal curves. The decline in the melting temperature of DNA following the addition of porphyrazine complexes confirms that the substantial mode of Ni and Fe interaction is not intercalation. The thermodynamic results imply that both Ni and Fe complexes have a slight destabilizing effect on the DNA. A comparison between [ Ni ( tmtppa )]4+ and [ Fe ( tmtppa )]4+ indicates that the latter is more effective than the former.
Abstract An ethylene diamine derivative of a bis(phenol)diamine ligand (H2L) was synthesized via ... more Abstract An ethylene diamine derivative of a bis(phenol)diamine ligand (H2L) was synthesized via the Mannich reaction and subsequent ring cleavage of the produced imidazoline ring (H2LIm), and then it was characterized by 1H NMR and IR spectroscopies and CHN analysis. The iron(III) complex (FeLCl) of this ligand was synthesized and characterized by IR, UV–Vis, X-ray and magnetic susceptibility studies. X-ray analysis reveals that in FeLCl the iron(III) center has a distorted square pyramidal coordination sphere and is surrounded by a chlorine atom, two amine nitrogen and two phenolate oxygen atoms of the ligand. Variable-temperature magnetic susceptibility measurements indicate that FeLCl is a paramagnetic high spin iron(III) complex. It shows weak antiferromagnetic interactions through N H⋯Cl intermolecular interactions. The ligand-centered electrochemical oxidation of this complex, due to the oxidation of phenolate group to phenoxyl radicals, as well as the electrochemical metal-centered reduction of the ferric ion to the ferrous ion were investigated. In addition, the efficient cleavage by oxygenation of 3,5-di-tert-butyl-catechol with FeLCl in the presence of dioxygen was observed.
A ZnTCPP-TiO2/CoFe2O4 nanohybrid easily reusable using a permanent magnet without losing its reac... more A ZnTCPP-TiO2/CoFe2O4 nanohybrid easily reusable using a permanent magnet without losing its reactivity for the selective production of aldehydes from a mechanistic point of view.
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