Cobalt | An-Najah Staff

Spectrophotometric and Polarographic Studies of Di-2-Pyridyl Ketone 2-Thienoylhydrazone

Thu, 2015-05-14 11:04 — Mohammed A. A. Hannoun

Journal Title, Volume, Page:

nalytical Letters Volume: 27 Issue: 10 Pages: 1907-1919 Published: 1994

Year of Publication:

1994

Link:

http://www.tandfonline.com/doi/abs/10.1080/00032719408002640#.VVR2PZP-n_J

Authors:

Ali Z. Abu Zuhri

Department of Chemistry, Faculty of Science, UAE , University, Al-Ain , P.O.Box 17551, United Arab Emirates

Mohamad S. El-Shahawi

Department of Chemistry, Faculty of Science, UAE , University, Al-Ain , P.O.Box 17551, United Arab Emirates

Mostafa M. Kamal

Department of Chemistry, Faculty of Science, UAE , University, Al-Ain , P.O.Box 17551, United Arab Emirates

Mohamad Al-Nuri

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Mohamed Hannoun

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

The spectral and differential pulse polarographic (DPP) behaviour of di-2-pyridyl ketone 2-thienoylhydrazone (DPKTH) has been investigated in 30% (v/v) ethanol-buffer mixtures over a wide range of pH (2.0-12.0). The spectral bands located at 325, 276. 230 and 208 nm of the DPKTH in ethanol are assigned to the possible electronic transitions of the molecule. The spectral data at various pH values indicates that the molecule characterized by the keto = enol tautomerization and the pK(a) value for the enolic form of the compound is determined in aqueous ethanol and was found to be 10.6. The effect of various operational parameters on the reduction current and the mechanism of the electrode reaction of DPKTH at the DME are discussed. The main reduction peaks are attributed to the reduction of C=N centre of both the keto and enol forms. This behaviour is compared with the DPP behaviour of the other related acid hydrazone compounds. The applicability of DPP technique for the trace determination of DPKTH was tested under the optimum experimental conditions and the detection limit is found to be 0.09 mu m.

Spectrophotometric Determination of Trace Amounts of Cobalt and Copper with 3- (2'-Thiazolylazo)- 2,6- Diaminopyridine

Thu, 2015-05-14 10:54 — Mohammed A. A. Hannoun

Journal Title, Volume, Page:

Spectroscopy Letters, Volume 25, Issue 7 November 1992 , pages 1049 - 1055

Year of Publication:

1992

Link:

http://www.tandfonline.com/doi/abs/10.1080/00387019208018214

Authors:

Basem F. Shraideh

Ali. Z. Abu Zuhri

Mohammad Hannoun

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Sensitive methods for the determination of trace amounts of cobalt and copper by complexation with 3-(2'-Thiazolylazo)-2,6- diaminopyridine (2,6-TADAP) are described. Copper forms a 1:2 violet complex with the reagent having a molar absorptivity of 1.00 times 104 L mol-1cm-1, Baer's law is obeyed over the range 0 -50.84 μg in the total volume of 10ml. Cobalt also forms a 1:1 green complex with a molar absorptivity of 1.07 times 104L mol-1cm-1 and obeying Beer's law over the range 0 -23.57 μg in the total volume of 10 ml. The procedure is simple and rapid without any tedious extraction steps for copper and without oxidation of cobalt (II) to cobalt (III).

Spectrophotemetric determination of cobalt in aqueous solution using di-2-pyridyl ketone derivatives

Thu, 2015-05-14 10:26 — Mohammed A. A. Hannoun

Journal Title, Volume, Page:

Analytica Chimica Acta, Volume 259, Issue 1, 5 April 1992, Pages 175-179

Year of Publication:

1992

Authors:

Mohammed A. Al-Nuri

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Maher Abud-Eid

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Nidal A. Zatar

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Shukri Khalaf

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Mohammed Hannoun

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Mustafa Khamis

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

A method for the spectrophotometric determination of cobalt(II) is presented, with a comparison of the binary complexes formed by cobalt(II) with di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), di-2-pyridyl ketone 2-thiophenoylhydrazone (DPKTH) and di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Cobalt(II) forms 1:2 complexes with the three reagents. Maximum absorbance is at 372 nm for Co(II)-DPKNH, at 389 nm for Co(II)-DPKTH and at 370 nm for Co(II)-DPKBH. Ranges of linearity, effects of pH and excess reagent, sensitivity, stability of the complexes and tolerance limits of ions are reported. It was concluded that the system with DPKTH is the best, followed by DPKNH and then DPKBH. The method was applied to the determination of cobalt in different alloys.

Kinetics, Equilibrium and Thermodynamic Studies on the Adsorptive Removal of Nickel, Cadmium ‎and Cobalt from Wastewater by Superparamagnetic Iron Oxide Nanoadsorbents

Mon, 2014-05-19 10:52 — Nashaat N. Nassar

Journal Title, Volume, Page:

The Canadian Journal of Chemical Engineering Volume 90, Issue 5, pages 1231–1238

Year of Publication:

2012

Link:

http://onlinelibrary.wiley.com/doi/10.1002/cjce.20613/abstract

Authors:

Nashaat N. Nassar

Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, Alberta, Canada, T2N 1N4

Current Affiliation:

Department of Chemical Engineering, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Because of its unique properties, such as specific functionality and large specific surface area, iron oxide nanoadsorbents had showed potential for energy and environmental applications. This work investigated the adsorptive removal of different metal ions from wastewater by superparamagnetic iron oxide nanoadsorbents (Fe₃O₄). Batch-adsorption technique was employed to assess the kinetic behaviour and adsorption equilibrium of cadmium, cobalt and nickel. Accordingly, the effect of the following variables on the adsorption reaction was tested, namely: solution pH, contact time and temperature. Metal ion adsorption was found to be highly pH dependent with a maximum uptake achieved around pH 5.5. Kinetic studies showed that adsorption was fast and equilibrium was achieved in less than 60 min. The external mass transfer kinetic model was applied to the experimental results and provided reasonable overall volumetric mass transfer coefficients. Adsorption isotherms were determined and appropriately described by the Freundlich and Langmuir models, with a better fit to the Freundlich model. The amount of metal ion adsorbed increased as the temperature increased, suggesting an endothermic adsorption process. The thermodynamics studies indicated that the adsorption process was spontaneous and endothermic in nature. © 2011 Canadian Society for Chemical Engineering

Spectrophotometric Determination of Cobalt in Aqueous Solution using Di-2-Pyridyl ‎Ketone Derivatives

Tue, 2014-04-01 10:07 — Mohammed Abdullah Al-Nuri

Journal Title, Volume, Page:

Analytica Chimica Acta Volume 259, Issue 1, Pages 175–179

Year of Publication:

1992

Link:

http://www.sciencedirect.com/science/article/pii/000326709285091J

Authors:

Mohammed A. Al-Nuri

Chemistry Department, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Maher Abud-Eid

Chemistry Department, An-Najah National University, Nablus, Palestine

Nidal A. Zatar

Chemistry Department, An-Najah National University, Nablus, Palestine

Shukri Khalaf

Chemistry Department, An-Najah National University, Nablus, Palestine

Mohammed Hannoun

Chemistry Department, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

A method for the spectrophotometric determination of cobalt(II) is presented, with a comparison of the binary complexes formed by cobalt(II) with di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), di-2-pyridyl ketone 2-thiophenoylhydrazone (DPKTH) and di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Cobalt(II) forms 1:2 complexes with the three reagents. Maximum absorbance is at 372 nm for Co(II)-DPKNH, at 389 nm for Co(II)-DPKTH and at 370 nm for Co(II)-DPKBH. Ranges of linearity, effects of pH and excess reagent, sensitivity, stability of the complexes and tolerance limits of ions are reported. It was concluded that the system with DPKTH is the best, followed by DPKNH and then DPKBH. The method was applied to the determination of cobalt in different alloys.

Spectrophotometric Determination of Cobalt in Aqueous Solution using Di-2-Pyridyl ‎Ketone Derivatives

Mon, 2014-03-31 10:11 — Nidal Zatar

Journal Title, Volume, Page:

Analytica Chimica Acta Volume 259, Issue 1, Pages 175–179

Year of Publication:

1992

Link:

http://www.sciencedirect.com/science/article/pii/000326709285091J

Authors:

Nidal A. Zatar

Chemistry Department, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Mohammed A. Al-Nuri

Chemistry Department, An-Najah National University, Nablus, Palestine

Maher Abud-Eid

Chemistry Department, An-Najah National University, Nablus, Palestine

Shukri Khalaf

Chemistry Department, An-Najah National University, Nablus, Palestine

Mohammed Hannoun

Chemistry Department, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

A method for the spectrophotometric determination of cobalt(II) is presented, with a comparison of the binary complexes formed by cobalt(II) with di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), di-2-pyridyl ketone 2-thiophenoylhydrazone (DPKTH) and di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Cobalt(II) forms 1:2 complexes with the three reagents. Maximum absorbance is at 372 nm for Co(II)-DPKNH, at 389 nm for Co(II)-DPKTH and at 370 nm for Co(II)-DPKBH. Ranges of linearity, effects of pH and excess reagent, sensitivity, stability of the complexes and tolerance limits of ions are reported. It was concluded that the system with DPKTH is the best, followed by DPKNH and then DPKBH. The method was applied to the determination of cobalt in different alloys.

Spectrophotometric Determination of Cobalt in Aqueous Solution using Di-2-Pyridyl ‎Ketone Derivatives

Wed, 2014-03-26 14:32 — Maher An-Natsheh

Journal Title, Volume, Page:

Analytica Chimica Acta Volume 259, Issue 1, Pages 175–179

Year of Publication:

1992

Link:

http://www.sciencedirect.com/science/article/pii/000326709285091J

Authors:

Maher Abud-Eid

Chemistry Department, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Mohammed A. Al-Nuri

Chemistry Department, An-Najah National University, Nablus, Palestine

Nidal A. Zatar

Chemistry Department, An-Najah National University, Nablus, Palestine

Shukri Khalaf

Chemistry Department, An-Najah National University, Nablus, Palestine

Mohammed Hannoun

Chemistry Department, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

A method for the spectrophotometric determination of cobalt(II) is presented, with a comparison of the binary complexes formed by cobalt(II) with di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), di-2-pyridyl ketone 2-thiophenoylhydrazone (DPKTH) and di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Cobalt(II) forms 1:2 complexes with the three reagents. Maximum absorbance is at 372 nm for Co(II)-DPKNH, at 389 nm for Co(II)-DPKTH and at 370 nm for Co(II)-DPKBH. Ranges of linearity, effects of pH and excess reagent, sensitivity, stability of the complexes and tolerance limits of ions are reported. It was concluded that the system with DPKTH is the best, followed by DPKNH and then DPKBH. The method was applied to the determination of cobalt in different alloys.

Spectrophotometric Determination of Trace Amounts of Cobalt and Copper with 3- (2′-Thiazolylazo)- 2,6- Diaminopyridine

Thu, 2014-03-20 13:05 — Bassem Shraydeh

Journal Title, Volume, Page:

Spectroscopy Letters: An International Journal for Rapid Communication Volume 25, Issue 7, Pages 1049-1055

Year of Publication:

1992

Link:

http://www.tandfonline.com/doi/abs/10.1080/00387019208018214#.UyrPQPmSwgY

Authors:

Bassem F. Shraydeha

Chemistry Department, Faculty of Science , An-Najah National University , Nablus, Palestine

Current Affiliation:

Department of Chemistry, An-Najah National University, Nablus, Palestine

[email protected]

Ali. Z. Abu Zuhria

Chemistry Department, Faculty of Science , An-Najah National University , Nablus, Palestine

Mohammad Hannouna

Chemistry Department, Faculty of Science , An-Najah National University , Nablus, Palestine

Preferred Abstract (Original):

Sensitive methods for the determination of trace amounts of cobalt and copper by complexation with 3-(2′-Thiazolylazo)-2,6- diaminopyridine (2,6-TADAP) are described. Copper forms a 1:2 violet complex with the reagent having a molar absorptivity of 1.00 × 10⁴ L mol⁻¹cm⁻¹, Baer's law is obeyed over the range 0 −50.84 μg in the total volume of 10ml. Cobalt also forms a 1:1 green complex with a molar absorptivity of 1.07 × 10⁴L mol⁻¹cm⁻¹ and obeying Beer's law over the range 0 –23.57 μg in the total volume of 10 ml. The procedure is simple and rapid without any tedious extraction steps for copper and without oxidation of cobalt (II) to cobalt (III).

Syntheses, Physico-Chemical Studies and Antioxidant Activities of Transition Metal Complexes with a Perimidine Ligand

Thu, 2013-03-14 17:41 — Ismail Warad

Journal Title, Volume, Page:

Zeitschrift für anorganische und allgemeine Chemie, Volume 638, Issue 5, pages 881–886, April 2012

Year of Publication:

2012

Link:

http://onlinelibrary.wiley.com/doi/10.1002/zaac.201100561/abstract?systemMessage...

Authors:

Dr. Mohammad Azam

Department of Chemistry, King Saud University, P. O. Box 2455, Riyadh 11451, KSA

[email protected]

Ismail Warad

Department of Chemistry, King Saud University, P. O. Box 2455, Riyadh 11451, KSA

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Saud Al-Resayes

Department of Chemistry, King Saud University, P. O. Box 2455, Riyadh 11451, KSA

Maryam Zahin

Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202 002, India

Iqbal Ahmad

Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202 002, India

Mohammad Shakir

Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India

Preferred Abstract (Original):

A series of mononuclear complexes of the type, [MLCl2] [M = CoII, NiII, CuII, and ZnII] with a pyrimidene-type ligand, which was synthesized by the reaction of 2-furaldehyde and 1, 8-diaminonaphthalene, was obtained. The ligand and its complexes were characterized by elemental analysis, IR, NMR, EPR, and UV/Vis spectroscopy, ESI-mass spectrometry, magnetic susceptibility, molar conductivity, and thermogravimetric analyses. On the basis of UV/Vis spectroscopic and magnetic susceptibility data, an octahedral arrangement was assigned around all metal ions. The low molar conductivity data for all the complexes show their non-electrolytic nature. The thermal behavior of the complexes was studied by TGA analyses. The electrochemical study carried out on the CuII complex exhibits a quasi reversible redox process. The ligand and its complexes showed potential antioxidant and antimicrobial activities.

Lifetimes, Branching Ratios, and Transition Probabilities in Co ii

Sun, 2013-03-03 09:50 — Dr. Subhi Saleh

Journal Title, Volume, Page:

Phys. Rev. A 31, 744–749 (1985)

Year of Publication:

1985

Link:

http://pra.aps.org/abstract/PRA/v31/i2/p744_1

Authors:

S. Salih

University of Wisconsin, Madison, Wisconsin 53706

Current Affiliation:

Department of Physics, Faculty of Sciences, An-Najah National University, Palestine

[email protected]

J. E. Lawler

University of Wisconsin, Madison, Wisconsin 53706

W. Whaling

Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125

Preferred Abstract (Original):

The radiative lifetime of 14 levels in the z⁵F, z⁵D, and z⁵G terms of Co ii have been measured with use of time-resolved laser fluorescence spectroscopy with a Co⁺-ion beam. Our lifetime values are shorter by 15–50 % than earlier results from beam-foil time-of-flight measurements. The lifetimes were converted to 41 individual transition probabilities with use of branching ratios measured on spectra recorded with the 1-m Fourier-transform spectrometer at the Kitt Peak National Observatory. On average our transition probabilities agree with those of Kurucz and Peytremann; for ΔS=1 transitions their calculated values are lower than our experimental results by a factor of ∼(1/4).