Thermodynamics of triaryltin chloride adduct complexes

2001 ◽  
Vol 79 (1) ◽  
pp. 70-74
Author(s):  
Mozaffar Asadi ◽  
Khosrow Aein Jamshid
Keyword(s):  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Thermodynamic Data ◽  
Lewis Acids ◽  
Mixed Solvent ◽  
Adduct Formation ◽  
Lewis Bases ◽  
Water Solvent ◽  
The Stability ◽  
Chloride Adduct

The stability constants and the thermodynamic data were measured spectrophotometerically for 1:1 adduct formation of triaryltin chlorides, where aryl groups are p-chlorophenyl, phenyl, p-, m-, and o-tolyl, as Lewis acids, with chloride and bromide ions, as Lewis bases, in 50% v/v ethanol-water solvent. The stability constants and the thermodynamic parameters trend, confirmed the following softness trend of tin(IV) in the triaryltin chlorides:(p-, m-, o-tolyl)3SnCl > (phenyl)3SnCl > (p-chlorophenyl)3SnClKey words: tin(IV) complexes, thermodynamic parameters, mixed solvent, adduct formation.

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 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.

A Thermodynamic Study of the Charge Transfer Complexes of Iodine with Different tert-Butylcalix[4]crowns

2005 ◽  
Vol 60 (11) ◽  
pp. 1133-1137 ◽  
Author(s):  
Shehadeh A. Mizyed ◽  
Muhammad Ashram ◽  
Riyadh Saymeh ◽  
Deeb Marji
Keyword(s):  
Charge Transfer ◽  
Stability Constants ◽  
Thermodynamic Data ◽  
Chloroform Solution ◽  
Thermodynamic Study ◽  
Charge Transfer Complexes ◽  
The Stability

Formation of the charge-transfer complexes between calix[4]crowns (1 - 4) and iodine in chloroform solution was studied using UV-vis spectrophotometry. The stability constants and the thermodynamic data of the resulting 1 : 1 complexes were determined and was found to decrease with increasing the size of the crown moiety of the calixcrown. All complexes formed were found to be enthalpy stabilized, and all except the complex of 2 were entropy destabilized.

Chalcones as Analytical Reagents of Aluminum: Stability, Thermodynamic and Kinetic Study

2015 ◽  
Vol 229 (3) ◽  
Author(s):  
Vanesa A. Muñoz ◽  
Carolina G. Kretek ◽  
M. Paulina Montaña ◽  
Nora  B. Pappano ◽  
Nora  B. Debattista ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Driving Force ◽  
Biological Properties ◽  
Polyphenolic Compounds ◽  
Formation Reaction ◽  
Long Time ◽  
Analytical Reagents ◽  
The Stability

AbstractChalcones, a group of polyphenolic compounds, has been studied for a long time due to their biological properties and their ability as analytical reagents. In this work the stability and thermodynamic parameters concerning the fotmation in ethanolic medium of two chalcone–aluminium complexes (2′,3-dihydroxychalcone-Al(III) and 2′,4′,3-trihydroxychalcone-Al(III)) were studied and a kinetic study of the formation reaction was aslo performed. Both systems showed 1:1 L : M stoichiometry and stability constants at four temperatures were determined. Thermodynamic parameters indicate that both formation reactions are endothermic and driving force is entropic. Kinetic study revealed that 2′,4′,3-trihydroxychalcone-Al(III) formation is faster than 2′,3-dihydroxyclacone-Al(III), a factor which can be interesting when proposing new analytical reagents.

scholarly journals Thermodynamic parameters for the complexation of technetium(IV) with EDTA

2018 ◽  
Vol 106 (12) ◽  
pp. 963-970 ◽  
Author(s):  
Mitchell T. Friend ◽  
Cecilia Eiroa Lledo ◽  
Lindsey M. Lecrivain ◽  
Donald E. Wall ◽  
Nathalie A. Wall
Keyword(s):  
Thermodynamic Parameters ◽  
Stability Constants ◽  
High Yield ◽  
Edta Complex ◽  
Liquid Liquid Extraction ◽  
Geological Repository ◽  
The Stability ◽  
Apparent Stability ◽  
Accurate Quantification ◽  
Acid Dependence

Abstract Technetium-99 is a high yield (~6% fission yield) fission product and long-lived (2.13×105 year half-life) component of nuclear waste that will be disposed of in a geological repository. Some 99Tc has been released into the environment due to nuclear fuel and weapon production activities at sites such as Hanford, WA. Strongly complexing ligands such as ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA) are known to increase Tc(IV) solubility and mobility in environmental systems and an accurate quantification of the complexation of Tc(IV) with EDTA is important for predicting its behavior in a geological repository. A liquid–liquid extraction system utilizing 0.2 M TOPO in dodecane was used to measure the stability constants of Tc(IV)-EDTA in 0.50 m NaNO3 at variable temperatures (14.0±0.1, 25.0±0.1, and 32.0±0.1°C). The acid dependence of the apparent stability constants in the pCH range of 2.00–2.70 indicated the formation of TcO(EDTA)2− (logβ101=17.9±0.3, 25.0±0.1°C) and a protonated complex TcO(H)(EDTA)− (logβ111=20.5±0.1, 25.0±0.1°C). The associated thermodynamic parameters ΔrG101=−101.7±0.4 kJ·mol−1, ΔrH101=−47±9 kJ·mol−1, ΔrS101=179±36 J·mol−1·K−1, ΔrG111=−117.2±0.3 kJ·mol−1, ΔrH111=−23±5 kJ·mol−1, and ΔrS111=315±63 J·mol−1·K−1 (0.50 m NaNO3, 25.0±0.1°C) were determined by van’t Hoff analysis. The formation of each Tc(IV)–EDTA complex is exothermic and present favorable entropy terms.

Thermodynamics of metal-ligand bond formation. XXI. Base adducts of nickel(II) glyoximato complexes

1976 ◽  
Vol 29 (6) ◽  
pp. 1201 ◽  
Author(s):  
DP Graddon ◽  
IA Siddiqi
Keyword(s):  
Thermodynamic Data ◽  
Bond Formation ◽  
Adduct Formation ◽  
Lewis Bases ◽  
Alkyl Groups ◽  
Metal Ligand ◽  
Ligand Bond

Bis(glyoximato)nicke1(11) complexes and their BF2-bridged derivatives react with Lewis bases in non-donor solvents forming low-spin 1 : 1 adducts. Thermodynamic data are reported for formation of adducts of glyoximato complexes with PBu3 and of BF2-bridged complexes with pyridine (py), 4-methylpyridine (mpy), piperidine (pip), tributylphosphine, triphenylphosphine, ethane-1,2-diyi- bis(diphenylphosphine) and tetrahydrothiophen. Adduct stability is increased by BF2-bridging; in the Pbu3 adducts this is due to entropy factors. Variation of alkyl groups in the glyoxinie has only a small effect, but replacement of alkyl by Ph or H increases adduct stability while lowering enthalpy of adduct formation. Average values of ΔH� and K (at 30�C) for adducts of BF2-bridged complexes and for PBu3 adducts of H-bridged complexes (last entry) are: PY mpy pip PPh3 PBu3 Pbu3 -ΔH� (kJ mol-l) 29 31 35 23 43 42 K (1.mol-1) 3 5 80 4 800 60

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