Effect of ionic strength of the solution of some hydrogen - bonded interpolymer complexes on the stability and thermodynamic parameters

Polimery ◽  
2009 ◽  
Vol 54 (04) ◽  
pp. 261-265 ◽  
Author(s):  
B. VASHEGHANI F. ◽  
F. H. RAJABI ◽  
M. H. AHMADI ◽  
A. GHOLEHZADEH
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Interpolymer Complexes ◽  
The Stability ◽  
Hydrogen Bonded

scholarly journals Potentiometric and spectrophotometric studies of the complexation of Schiff-base hydrazones containing the pyrimidine moiety

2003 ◽  
Vol 68 (10) ◽  
pp. 729-749 ◽  
Author(s):  
H.S. Seleem ◽  
B.A. El-Shetary ◽  
S.M.E. Khalil ◽  
M. Shebl
Keyword(s):  
Schiff Base ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Dissociation Constants ◽  
The Stability ◽  
Pyrimidine Moiety ◽  
Metal Ligand

Three Schiff-base hydrazones (ONN ? donors) were prepared by condensation of 2-amino-4-hydrazino-6-methylpyrimidine with 2-hydroxyacetophenone 2-methoxybenzaldehyde and diacetyl to yield 2-OHAHP, 2-OMeBHPand DHP respectively. The structures of these ligands were elucidated by elemental analysis, UV, IR, 1H-NMR and mass spectra. The metal?ligand stability constants of Mn2+, Fe3+,Co2+,Ni2+,Cu2+, Zn2+,Cd2+,UO22+ and Th4+ chelates were determined potentiometrically in two different media (75%(v/v) dioxane?water and ethanol?water) at 283, 293, 303 and 313 K at an ionic strength of 0.05 M (KNO3). The thermodynamic parameters of the 1:1 and 1:2 complexes were evaluated and are discussed. The dissociation constants of 2-OHAHP, 2-OMeBHP and DHPligands and the stability constants of Co2+, Ni2 and Cu2+ with 2-OHAHP were determined spectrophotometrically in 75 % (v/v) dioxane?water.

Effect of added salt on the stability of hydrogen-bonded interpolymer complexes

1996 ◽  
Vol 274 (6) ◽  
pp. 532-539 ◽  
Author(s):  
V. A. Prevysh ◽  
B. -C. Wang ◽  
R. J. Spontak
Keyword(s):  
Interpolymer Complexes ◽  
The Stability ◽  
Added Salt ◽  
Hydrogen Bonded

Synthesis, characterization, and thermodynamics of tertiary phosphine cobalt(III) Schiff-base complexes

2001 ◽  
Vol 79 (9) ◽  
pp. 1360-1365 ◽  
Author(s):  
Mozaffar Asadi ◽  
Ali Hossein Sarvestani
Keyword(s):  
Schiff Base ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Schiff Base Complex ◽  
Axial Ligand ◽  
Adduct Formation ◽  
Schiff Base Complexes ◽  
Tertiary Phosphine ◽  
The Stability

[Co(5-nitroSalen)(PBu3)]ClO4·H2O and [Co(Salpd)(PBu3)]ClO4·H2O were synthesized and characterized. The stability constants and the thermodynamic parameters were measured spectrophotometrically for 1:1 adduct formation of [CoL(PBu3)]ClO4·H2O, (L = Salen, 5-nitroSalen, Salpd), and [Co(Salen)(PMe2Ph)]ClO4·H2O as acceptors with P(OR)3, (R = Me, Et, i-Pr) as donors, in acetonitrile solvent and in constant ionic strength (I = 0.01 M) and at various temperatures. The trend of the reactivity of cobalt(III) Schiff-base complexes with PBu3 axial ligand toward a given donor is as follows: 5-nitroSalen > Salen > Salpd.Also, the following reactivity trend of the donors toward a given cobalt(III) Schiff-base complex is in the operation: P(O-i-Pr)3 > P(OEt)3 > P(OMe)3.Key words: cobalt(III) Schiff-base complexes, thermodynamic parameters, trialkylphosphite, adduct complexes, stability constants.

scholarly journals Qualitative Investigation on some H-bonded Interpolymer Complexes by Determination of Thermodynamic Parameters

2017 ◽  
Vol 56 (2) ◽  
Author(s):  
Bahman Vasheghani Farahani ◽  
Farzaneh Hosseinpour Rajabi ◽  
Mohammad Hoseein Ahmadi ◽  
Naser Zenooz
Keyword(s):  
Thermodynamic Parameters ◽  
Interpolymer Complex ◽  
Ionic Polymers ◽  
Interpolymer Complexes ◽  
Dipole Interactions ◽  
Two Factors ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
The Stability

Qualitative analysis for stability of some hydrogen bonded interpolymer complexes of poly (acrylic acid) with non ionic polymers such as poly (methacryl amide) (PMAm), poly (vinyl pyrrolidon) (PVP), poly (ethylene oxide) (PEO) and poly (ethylene glycol) (PEG), has been done by determining the stability constant (K) and thermodynamic parameters (e.g. ΔH<sup>0</sup> and ΔS<sup>0</sup>) of these complexes at several temperatures. The comparative studies indicate considerable difference in the values of these parameters. They can be explained on the basis of influence of other interacting forces such as hydrophobic and ion dipole interactions during interpolymer complex formation. It has been found that the stability of H-bonding interpolymer complex is greatly enhanced by these two factors.

scholarly journals The Stability Constants and Thermodynamic Parameters of Borate - Carbohydrate Complexes by pH Measurements

2012 ◽  
Vol 25 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Farida Akhtar ◽  
Md Anisur Rahman ◽  
DM Shafiqul Islam ◽  
Md Anamul Hoque
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Chemical Society ◽  
Ph Measurements ◽  
Negative Contribution ◽  
Exothermic Process ◽  
Different Temperatures ◽  
The Stability

The complexation of borate with carbohydrates was studied potentiometrically at  temperatures 298.15-328.15K in aqueous medium at constant ionic strength, I = 0.1M  KCl. The stability constants (?) and thermodynamic parameters of borate-carbohydrate  complexes were determined using the technique proposed by Verchere and Hlaibi.  Carbohydrates such as D-fructose, D-Sorbitol, D-Mannitol, D-Galactose, D-Glucose and  D-Raffinose were used as ligands in this study. The ?1 values for the complexes at  different temperatures were found to follow the order: D-fructose > D-Sorbitol > DMannitol > D-Galactose > D-Glucose > D-Raffinose. The ?G0 values were found to be  negative and the negative values increased according to the above order. The values of  ?H0 and ?S0 were both negative which indicated that the complex formation was an  exothermic process and the spontaneity of its formation is driven by enthalpic  contribution overcoming the negative contribution of ?S0. DOI: http://dx.doi.org/10.3329/jbcs.v25i1.11766 Journal of Bangladesh Chemical Society, Vol. 25(1), 15-20, 2012

Polymerization of acrylonitrile initiated by peroxomonosulphate-thiols redox systems

1990 ◽  
Vol 55 (8) ◽  
pp. 2001-2007
Author(s):  
Gurusamy Manivannan ◽  
Pichai Maruthamuthu
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Thermal Polymerization ◽  
Reaction Scheme ◽  
Degree Of Polymerization ◽  
Reducing Agent ◽  
Redox Systems ◽  
Temperature Range ◽  
Rate Of Polymerization

Aqueous thermal polymerization of acrylonitrile (AN) initiated by peroxomonosulphate (HSO5-, PMS)-thiolactic acid (TLA) and PMS-thiomalic acid (TMA) redox systems has been carried out in the temperature range 30-50 °C. The effect of concentration of monomer, initiator, reducing agent, H+, and ionic strength on rate of polymerization, Rp, has been investigated under deaerated conditions. The Rp has been found to depend on, Rp ~ [AN]01.5 [PMS]0.5 [TLA]0.5 in PMS-TLA system and, Rp ~ [AN]02.0 [PMS]1.0 [TMA]0 in PMS-TMA system. The degree of polymerization (Xn) values and thermodynamic parameters have been evaluated. Suitable reaction scheme has been proposed and expressions for Rp and Xn have been obtained.

Thermodynamic Studies of the Core Histones:  pH and Ionic Strength Effects on the Stability of the (H3−H4)/(H3−H4)2System†

Biochemistry ◽  
1996 ◽  
Vol 35 (6) ◽  
pp. 2037-2046 ◽  
Author(s):  
Vassiliki Karantza ◽  
Ernesto Freire ◽  
Evangelos N. Moudrianakis
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Studies ◽  
The Core ◽  
Core Histones ◽  
The Stability

scholarly journals Stability Studies of Transition Metal Chelates of 5-Bromosalicylidene-4-methoxyaniline andSalicylidene-2,3-dimethylaniline as Ligands

2011 ◽  
Vol 8 (4) ◽  
pp. 1911-1915
Author(s):  
N. G. Nadkarni ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Transition Metal ◽  
Stability Constants ◽  
Metal Chelates ◽  
Ternary Complexes ◽  
Water Medium ◽  
Stability Studies ◽  
Binary And Ternary Complexes ◽  
Transition Metal Chelates ◽  
The Stability

Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II), Ni(II), Cu(II) and Zn(II); X = 5-bromosalicylidene-4-methoxyaniline and Y = salicylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5°C and at constant ionic strength, μ = 0.1 M (KCl) in 75 : 25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated.

scholarly journals Effects of electron transfer on the stability of hydrogen bonds

2017 ◽  
Vol 8 (11) ◽  
pp. 7324-7329 ◽  
Author(s):  
Tyler M. Porter ◽  
Gavin P. Heim ◽  
Clifford P. Kubiak
Keyword(s):  
Electron Transfer ◽  
Hydrogen Bonds ◽  
Ruthenium Complexes ◽  
Complementary Pair ◽  
Redox States ◽  
The Stability ◽  
Hydrogen Bonded

The measurement of the dimerization constants of hydrogen-bonded ruthenium complexes (12, 22, 32) linked by a self-complementary pair of 4-pyridylcarboxylic acid ligands in different redox states is reported.

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