Thermodynamic function of valineacid in n-n dimethyl formamide mixtures from conductance measurement

Sanaa T. Sarhan

doi:10.21123/bsj.2013.10.4.1172-1181

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Publication Date

Sun Dec 01 2013

Journal Name

Baghdad Science Journal

Volume

10

Issue Number

4

DOI

10.21123/bsj.2013.10.4.1172-1181

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Thermodynamic function of valineacid in n-n dimethyl formamide mixtures from conductance measurement

valine

Dimethyl formaide

Thermodynamic function

conductance measurement

Sanaa T. Sarhan

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Some physical properties enthalpy (?H), entropy (?s), free energy (?G),capacities(?cp?) and Pka values) for valine in dimethyl foramideover the temperature range 293.15-318.15K, were determined by direct conductance measurements. The acid dissociation at six temperature was examined at solvent composition x2) involving 0.141 of dimethyl foramide . As results, calculated values have been used to determine the dissociation constant and the associated thermodynamic function for the valine in the solvent mixture over temperatures in the range 293.15-318.15 k. The Pka1, and Pka2 were increased with increasing temperature.

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Publication Date

Fri Sep 20 2024

Journal Name

Journal Of Nano Research

Impact of Copper Doping on Nanocrystalline SnO2 Thin Films Synthesized by Sol-Gel Coating and Chemical Bath Deposition for Gas Sensor Applications

: Spin coating

SnO2 thin films

CBD

AFM

XRD

gas sensor

Selma M.H.

Mohammed

Isam M.

Amel S.

Abdulhussain K.

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This work focuses on the preparation of pure nanocrystalline SnO2 and SnO2:Cu thin films on cleaned glass substrates utilizing a sol-gel spin coating and chemical bath deposition (CBD) procedures. The primary aim of this study is to investigate the possible use of these thin films in the context of gas sensor applications. The films underwent annealing in an air environment at a temperature of 500 ^◦C for duration of 60 minutes. The thickness of the film that was deposited may be estimated to be around 300 nm. The investigation included an examination of the structural, optical, electrical, and sensing characteristics, which were explored across various preparation circumstances, specifically focusing on varied

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(3)

(1)

Publication Date

Wed Jan 01 2020

Journal Name

Modern Sport

Special exercises according to the Dynafoot data and its effect on the force index and the performance of the front straight air flip skill on the ground movements mat device

دعاء

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Publication Date

Wed Sep 25 2013

Journal Name

International Journal For Sciences And Technology

Synthesis, Characterization, And Antibacterial Activities Of Manganese (II),Cobalt(II), Copper(II) ,Iron (II), Nickel (II) And Cadmium(II) Mixed- Ligand Complexes Containing Amino Acid( L- Lysine) And 1,10-Phenanthroline

Taghreed

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The research includes the synthesis and identification of the mixed ligands complexes of M(II) Ions in general composition [M(Lyn)2(phen)] Where L- lysine (C6H14N2O2) commonly abbreviated (LynH) as a primary ligand and 1,10-phenanthroline(C12H8N2) commonly abbreviated as "phen," as a secondary ligand . The ligands and the metal chlorides were brought in to reaction at room temperature in ethanol as solvent. The reaction required the following molar ratio [(1:1:2) (metal): phen:2 Lyn -] with M(II) ions, were M = Mn(II),Cu(II), Ni(II), Co(II), Fe(II) and Cd(II). Our research also includes studying the bio–activity of the some complexes prepared against pathogenic bacteria Escherichia coli(-),Staphylococcus(-) , Pseudomonas (-), Bacillus (-)

Publication Date

Sun Jun 01 2008

Journal Name

Baghdad Science Journal

Synthesis and characterization of VO(II), Cr(III),Mn(II), Fe(II),Zn(II),Cd(II),Hg(II) and UO2(VI) complexes with ligands containing (ONO) and (ON) donor set atoms

Abbas.ALi.Salih.

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A new Schiff base o-hydroxybenzylidene-1-phenyl-2,3-dimethyl-4-amino-3-pyrazolin-5-on (HL) ,have been prepared and characterization.(HL) has been used as a chelating ligand to prepare a number of metal complexes VO(II) ,Cr(III) ,Mn(II),Fe(II),Hg(II) and UO2(II) .and mixed ligands complexes have been prepared between o-hydroxybenzylidene-1-phenyl-2,3-dimethyl-4-amino-3-pyrazolin-5-on and 8- hydroxy quinoline with VO(II),Zn(II),Cd(II), Hg(II) and UO2(II) the prepared complexes were isolated and characterized by (FT-IR)and (UV-Vis) spectroscopy. Elemental analysis (C.H.N) Chloride contents, Flame atomic absorption technique. in addition to magnetic susceptibility and conductivity measurement. Molar ratio measurement in solution gave comparabl

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(1)

Publication Date

Thu Apr 01 2021

Journal Name

Chaos, Solitons & Fractals

Modeling and analysis of an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.svg"><mml:mrow><mml:mi>S</mml:mi><mml:msub><mml:mi>I</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:msub><mml:mi>I</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>R</mml:mi></mml:mrow></mml:math> epidemic model with nonlinear incidence and general recovery functions of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.svg"><mml:msub><mml:mi>I</mml:mi><mml:mn>1</mml:mn></mml:msub></mml:math>

A.A

Raid Kamil

F

A.

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(19)

(17)

Publication Date

Wed May 01 2024

Journal Name

Journal Of Physics: Conference Series

Analyze the Structure and Electrical Properties of PbBr2 Ca1.9Sb0.1Cu3O8+ δ Superconducting Gamma Irradiation

Radiation

Gamma

Zero critical temperature

properties of Superconducting and XRD

Rafah

Hind

Marwah

Kareem. A.

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The purpose of the current work was to evaluate the effect of Radiation of Gamma on the superconducting characteristics of the compound PbBr2Ca1.9Sb0.1Cu3O8+δ utilizing a 137Cs source at doses of 10, 15, and 20MRad. Solid state reaction technology was used to prepare the samples. Before and after irradiation, X-ray diffraction (XRD) and superconductor properties were examined. Results indicated that the tetragonal structure of our chemical corresponds to the Pb-1223 phase with an increase in the ratio c/a as a result of gamma irradiation. (Tc (onset) ) and on set temperature Tc (offset)) were also dropping from 113 to the 85.6 K and 129.5 to 97 K, respectively, for a transition temperatu

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Publication Date

Tue Jan 01 2019

Journal Name

Inorganica Chimica Acta

Synthesis, characterisation and electrochemistry of eight Fe coordination compounds containing substituted 2-(1-(4-R-phenyl-1H-1,2,3-triazol-4-yl)pyridine ligands, R = CH3, OCH3, COOH, F, Cl, CN, H and CF3.

(1

2

3-Triazol-4-yl)pyridine Redox potential Iron DFT

Kinaan M

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Eight different Dichloro(bis{2-[1-(4-R-phenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})iron(II) compounds, 2–9, have been synthesised and characterised, where group R=CH3 (L2), OCH3 (L3), COOH (L4), F (L5), Cl (L6), CN (L7), H (L8) and CF3 (L9). The single crystal X-ray structure was determined for the L3 which was complemented with Density Functional Theory calculations for all complexes. The structure exhibits a distorted octahedral geometry, with the two triazole ligands coordinated to the iron centre positioned in the equatorial plane and the two chloro atoms in the axial positions. The values of the FeII/III redox couple, observed at ca. −0.3 V versus Fc/ Fc+ for complexes 2–9, varied over a very small potential range of 0.05 V.

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Publication Date

Sat Sep 01 2018

Journal Name

Polyhedron

Novel dichloro (bis {2-[1-(4-methylphenyl)-1H-1, 2, 3-triazol-4-yl-κN3] pyridine-κN}) metal (II) coordination compounds of seven transition metals (Mn, Fe, Co, Ni, Cu, Zn and Cd)

The 1

3-dipolar cycloaddition “click” reaction between an azide and an alkyne to give a 1

2

3-triazole was reported by Huisgen in 1961 [1]. In 2002 the Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC) to prepare a 1

2

3-triazole was reported [2]

[3]. The existence of relatively basic nitrogen atoms in the 1

2

3-triazole rings

and the possibility of introducing additional donor groups in the substituents (Fig. 1)

made the CuAAC “click” reaction an attractive method to prepare differently substituted 1

2

3-triazoles. These compounds have been used as ligands to coordinate to various metal ions that display a range of applications such as in electrochemical and photochemical studies

in supramolecular chemistry

magnetism

metal-ion sensing and catalysis [4]. The reasons for the success of the “click” reaction

is that it is easy to carry out and is widely applicable. It is not affected by a variety of functional groups

and can be carried out with a variety of Cu(I) catalysts and solvents

including aqueous conditions. The Cu(I) catalysts overcome the high activation energy barrier of the non-catalyzed Huisgen reaction by changing the mechanism of the reaction. A large variety of copper catalysts can be used for the CuAAC reaction

on condition that the maximum concentration of Cu(I) species is generated during the reaction. The pre-catalyst can be a Cu(II) salt (usually CuSO4) together with a reducing agent (often sodium ascorbate) or a Cu(I) compound in the presence of a base or amine ligand and a reducing agent to prevent oxidation to Cu(II). Some strong oxidising cupric salts or complexes such as Cu(OAc)2 also work. The solvent is very flexible from organic to aqueous

with the most commonly used combination water + an alcohol (t-BuOH

MeOH or EtOH). The key role of the solvent or solvent mixture is to solubilize the substrates and Cu(I) catalyst in order to ensure rapid reactions. Such aqueous conditions are very useful for biochemical conjugations

as well as for organic syntheses. We recently reported on the synthesis of a series of differently substituted 1

2

3-triazole chromophores

the substituted 2-(1-phenyl-1H-1

2

3-triazol-4-yl)pyridine ligands [5]

see Fig. 2 middle

with substituents R = H (L1)

CH3 (L2)

OCH3 (L3)

COOH

F

Cl

CN

CF3

O(CH2)3CH3 and N(CH3)2. These versatile ligands were found to coordinate to various first row transition metals

such as manganese

cobalt and nickel [6]. Here we extend the series to include more first row transition metal(II) coordination compounds

iron

copper and zinc

as well as a second row transition metal(II) coordination compound

cadmium

containing the 2-(1-(4-methyl-phenyl)-1H-1

2

3-triazol-1-yl)pyridine chromophore (Fig. 2 right with R = CH3). This series of seven novel coordination compounds is the first series of pyridyl-triazole based transition metal coordination compounds where seven different transition metals are coordinated to the same 1

2

3-triazole chromophore

namely 2-(1-(4-methyl-phenyl)-1H-1

2

3-triazol-1-yl)pyridine.

Kinaan M

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Publication Date

Sat Sep 23 2017

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

Synthesis and Charact'erizatio.n of new Schiff base ligand [(2-{1-[(2 hydraxyÂ benzylidene)-hydrazono]-ethyl} benzene-I, 3, 5--triol.] and it's CQmp.lexes. with Co en\ Ni . (U),, cÂ·u(U)' and Â· zn(II).

A.Â·

...Show More Authors

The eaction of 2 4 .6-trihydroxyactophenonemonohydra1e with

l hydr.azine monohydrate was realized tiÂ·nder reflu.(( in methanol and i:l.

Jew drops of glacial acetic acid we.re added to give lhe'(int rmediate)

2-(1hydr pno-ctbyt)-benzcne-Â·1.3.5-r:Qql, which reacted wittl

saEcy.laldehyde. jn methm)ql to gjy;e 'a new :tyRe CNzOi) Ligand (H:flL]

f(2-{1-[(2-=bydroxy-bertzylideÂ·ne)-bydrazqoo,J-eÂ·thy.1}bcnzeÂ·neJ ;3Â·,5

of

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Publication Date

Mon Jul 01 2013

Journal Name

Iraqi Journal Of Agricultural Sciences مجلة العلوم الزراعية العراقية

EFFECT OF HARROW TYPE AND DRILL SEEDER'S SPEEDS AND DEPTHS ON SOME MACHINERY UNIT TECHNICAL, ECONOMICAL AND ENERGY REQUIREMENT INDICATORS تأثير نوع المنعمة وسٌرع وأعماق البذار في بعض المؤشرات الفنية والأقتصادية ومتطلبات القدرة للوحدة الميكنية

K. M.

L. A. Z.

F. F. M.

...Show More Authors

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