Formation constant

حرية الوصول المقاله

1 - Interaction of Dioxovanadium(V) Ion with Methionine at Different Ionic Strengths
M. Kia F. Gharib G. Ghasemi

The dependence on ionic strength of protonation of methionine and its complexation with dioxovanadium(V) isreported in sodium perchlorate solution as supporting electrolyte. The measurements have been performed at 25􀁻C using a combination of potentiometric and spectrop أکثر

The dependence on ionic strength of protonation of methionine and its complexation with dioxovanadium(V) isreported in sodium perchlorate solution as supporting electrolyte. The measurements have been performed at 25􀁻C using a combination of potentiometric and spectrophotometric techniques. The overall analysis of the presentand the previous data dealing with determination of stability constants at different ionic strengths allowed us toobtain a general equation, by which a formation constant determined at a fixed ionic strength can berecalculated, with a good approximation for another ionic strength in the range of 0.1 0.7 mol dm-3. تفاصيل المقالة

حرية الوصول المقاله

2 - Hydrolysis of cadmium cation in different ionic strength
Farahnaz Soleimani Hossein Aghaie Farrokh Gharib

The hydrolysis of cadmium nitrate was studied spectrophotometrically at different ionic strengthsof sodium perchlorate in a wide pH range, 1-12, and at 25 C. Least squares calculations areconsistent with the formation of M(OH)+, M(OH)2, M(OH)3- and M(OH)42- species, whi أکثر

The hydrolysis of cadmium nitrate was studied spectrophotometrically at different ionic strengthsof sodium perchlorate in a wide pH range, 1-12, and at 25 C. Least squares calculations areconsistent with the formation of M(OH)+, M(OH)2, M(OH)3- and M(OH)42- species, which M isCd2+. The dependency on ionic strength in the background electrolyte solutions was taken intoaccount by using a Debye-Huckel type equation, and finally the results have been compared withdata previously reported and interpreted. تفاصيل المقالة

حرية الوصول المقاله

3 - Complexation of alkali metal ions by totrapropary-monoamine and tetrabutoxytriamine utak] arenes
Noushin Osouleddini Karim Zare

The complexive abilities of 5,11,17-tddert-butyl-23 amino-25.26,27,28-tet3propoxy-calix[4]arere and5,1127-tri-amino-23 acelyktert-butylamide-25,26,27,28-tetrabutoxy-calixplarene towards alkali metalions Lit Nat, Kt RIC and Cs+ in methanol-chloroform mixture have been ev أکثر

The complexive abilities of 5,11,17-tddert-butyl-23 amino-25.26,27,28-tet3propoxy-calix[4]arere and5,1127-tri-amino-23 acelyktert-butylamide-25,26,27,28-tetrabutoxy-calixplarene towards alkali metalions Lit Nat, Kt RIC and Cs+ in methanol-chloroform mixture have been evaluated at 25 °C, using UVVis spectrophotometric techniques. The results showed that the hgands are capable to complex with all ofthe alkali cations by LI metal to ligand ratios The selectivity presented considering the calculatedformation constants are in the order Li* > Na > C, Kb+ > Cs for the ligands تفاصيل المقالة

حرية الوصول المقاله

4 - Ionic Strength Dependence of Formation Constants: Complexation of Dioxouranium (VI) with Aspartic Acid
Farrokh Gharib Karim Zare Ramin Cheraghali

The dependence on ionic strength of protonation of L-aspartic acid and its complexation withdioxouranium(VI) is reported in sodium perchlorate solution as a background salt. The measurementshave been performed at 25 ± 0.1 °C and various ionic strengths in the أکثر

The dependence on ionic strength of protonation of L-aspartic acid and its complexation withdioxouranium(VI) is reported in sodium perchlorate solution as a background salt. The measurementshave been performed at 25 ± 0.1 °C and various ionic strengths in the range 0.1 to 1.0 mol dm-3, using acombination of potentiometric and spectrophotometric techniques. The overall analysis of the present andthe previous data dealing with the determination of stability constants at different ionic strengths allowedus to obtain a general equation, by which a formation constant determined at a fixed ionic strength can becalculated, with a good approximation, at another ionic strength, if 0.1 ≤ ionic strength ≤ 1.0 mol dm-3sodium perchlorate. تفاصيل المقالة

حرية الوصول المقاله

5 - Thermodynamic study of interaction between phthalocyanines with calf thymus DNA
M. Aghaie F. Naderi M. Monajjemi H. Aghaie N. Safari P.R. Jamaat

The experimental determination of formation constant for interaction of two water soluble phthalocyanines,Cobalt (II) 4,4',4",4'"-tetrasulpho phthalocyanine (CoTsPc ) and Manganese(II) 4,4',4",4"-tetrasulphophthalocyanine (MnTsPc ) , with calf thymus DNA have been studi أکثر

The experimental determination of formation constant for interaction of two water soluble phthalocyanines,Cobalt (II) 4,4',4",4'"-tetrasulpho phthalocyanine (CoTsPc ) and Manganese(II) 4,4',4",4"-tetrasulphophthalocyanine (MnTsPc ) , with calf thymus DNA have been studied by UV-Vis spectrophotometric methodat lrnM phosphate buffer , pH 7.4 and at 5 different temperatures 20,25,30,35 and 400CC . The changes of Uv-Vis absorption spectra during the titration of these phthalocyanines with calf thymus DNA revealed a largehypochromicity (up to 45%) of the phthalocyanines maximum bands, usually considered as proof ofphthalocyanine intercalation in to DNA. The calculated formation constants, Ks , according to theSQUAD software were in the range of 104-105 M-1.By using the Van't Hoff equation. The values of enthalpyand entropy changes associated to the (CoTsPc +DNA) and(MnTsPc+DNA) were determined .Then by using AG°=-RTLIIK, we calculated the values of AG° at consideredtemperatures. Our results showed strong electrolytic effects on phthalocyanines behavior and increasingNaCl concentration induced self-aggregation of the CoTsPc and MnTsPc. تفاصيل المقالة

حرية الوصول المقاله

6 - Ionic str4ength dependence of formation constants, complexation of Glycine with dioxouranium (VI) Ion
Farrokh Gharib Ali Shamel Farbod Lotfi

The dependence on ionic strength of protonation of glycine and its complexation with dioxouranium (VI) is reported in sodium perchlorate and sodium chloride solutions as background salts. The measurements have been performed at 25±0.1°C and various ionic stre أکثر

The dependence on ionic strength of protonation of glycine and its complexation with dioxouranium (VI) is reported in sodium perchlorate and sodium chloride solutions as background salts. The measurements have been performed at 25±0.1°C and various ionic strengths in the range 0.1 to 1.0 mol , using a combination of potentiometric and spectrophotometric techniques. The overall analysis of the present and the previous data dealing with the determination of stability constants at different ionic strengths allowed us to obtain a general equation, by which a formation constant determined at a fixed ionic strengths can be calculated, with a good approximation, at another ionic strength, if 0.1 ionic strength 1.0 mol sodium perchlorate or sodium chloride. تفاصيل المقالة

حرية الوصول المقاله

7 - Thermodynamic Studies on the Interaction of Phthalocyanine with Bovine serum albumin
K. Zare H. Aghaie M. Mirzaie M.R. Zardoost F. Khazali

Using UV-Vis spectrophotometric method the interaction of water soluble phthalocyanine, Cobalt(ΙΙ) 4,4′,4′′,4′′′- tetrasulfophthalocyanine(CoTSPc), with bovine serum albumin (BSA) to determine the formation constant and rela أکثر

Using UV-Vis spectrophotometric method the interaction of water soluble phthalocyanine, Cobalt(ΙΙ) 4,4′,4′′,4′′′- tetrasulfophthalocyanine(CoTSPc), with bovine serum albumin (BSA) to determine the formation constant and related thermodynamic functions. The measurements were considered in 1mM sodium phosphate buffer, pH 7.0 and at 5 different temperatures 20, 25, 30, 35 and 40ºC. The results showed that the best fitting corresponds to a 1:1 complex model between BSA and CoTSPc. The optical adsorption spectra of phthalocyanine was analyzed in order to obtain binding constants, K, using SQUAD software. By using the Van’t Hoff equation, values of enthalpy, ∆H˚,and entropy, ∆S˚,changes associated to the (BSA+ CoTSPc) were determined, and the values of ∆G˚ were calculated by using ∆G˚ = -RTlnK at 5 different temperatures. تفاصيل المقالة

حرية الوصول المقاله

8 - The pH effect on complexation of Alkali metal cation by p-sulfonatocalix (4) arene in aqueous solution
K. Zare N. Osouleddini

The complexation of Alkali metal cations by the water-soluble p-sulfonic acid calix(4)arenewas thermodynamically characterized using spectrophotometeric data which are consistentwith the formation of a 1:1 complex resulting from electrostatic interactions between thesul أکثر

The complexation of Alkali metal cations by the water-soluble p-sulfonic acid calix(4)arenewas thermodynamically characterized using spectrophotometeric data which are consistentwith the formation of a 1:1 complex resulting from electrostatic interactions between thesulfonato groups and alkali metal cations. In this study, we determined the formationconstants (log K) of the complexes and have compared in deferent pH (1.0 and 1.5) at 25°C. تفاصيل المقالة

حرية الوصول المقاله

9 - Interaction of Phthalocyanine with Egg albumin and Bovine serum albumin
K. Zare H. Aghaie M. Mirzaie

The interaction of bovine serum albumin ( BSA) and egg albumin with water solublephthalocyanine, cobalt (ΙΙ) 4, 4′ , 4′′, 4′′′- tetrasulfophthalocyanine ( CoTSPc) , has been studiedby the UV- Vis method at pH 7.0 and five di أکثر

The interaction of bovine serum albumin ( BSA) and egg albumin with water solublephthalocyanine, cobalt (ΙΙ) 4, 4′ , 4′′, 4′′′- tetrasulfophthalocyanine ( CoTSPc) , has been studiedby the UV- Vis method at pH 7.0 and five different temperatures 20, 25, 30, 35 and 40°C. Theformation constants have been elucidated by using spectrophotometric titration and computerSQUAD program data refinement. The thermodynamic parameters ΔH°, ΔG°and ΔS° at 5 differenttemperatures were calculated. The results showed that the best fitting corresponds to a 1: 1complex model between BSA and egg albumin with CoTSPc. Formation constants decrease withincreasing temperature.The formation constants showed that bonding effect between egg albuminand CoTSPc is stronger than BSA. تفاصيل المقالة

حرية الوصول المقاله

10 - Synthesis and Solution Complexation Studies of a new Schiff base Ligand
Mahmood Payehghadr Farzaneh Nourifard Mehdi Kalhor Chiman Shahoei

A new Schiff base ligand, 2,2'-{pyridine-2,6-diylbis[nitrilo(E)methylylidene]}bis(4 bromophenol),has been synthesized by reaction of the 2,6-diamino pyridine with 5-bromo salicylaldehyde at ethanolunder refluxing. The structure of the synthesized compound resulted from أکثر

A new Schiff base ligand, 2,2'-{pyridine-2,6-diylbis[nitrilo(E)methylylidene]}bis(4 bromophenol),has been synthesized by reaction of the 2,6-diamino pyridine with 5-bromo salicylaldehyde at ethanolunder refluxing. The structure of the synthesized compound resulted from the IR, 1HNMR, MS andUV spectroscopy and elemental analysis data. Formation Constant (kf) value of it’s complexes withCu2+, Ni2+, Cd2+, Co2+ and Hg2+ has been determined Conductometrically. The formation constants ofthe resulting 1:1 complexes have been calculated from the computer fitting of the molar conductance- mole ratio data at different temperatures. The stability of the complexes to vary in acetonitrilesolvent was in the order of Cu2+ > Cd2+ > Co2+ > Hg2+ > Ni2+. The enthalpy and entropy changes ofthe complexation reactions have been evaluated from the temperature dependence of formationconstants. تفاصيل المقالة

حرية الوصول المقاله

11 - Investigate formation constant of some Amino Acids by p-sulphonato-calix (4) arene in Aqueous Solution
Noushin Osouleddini

The formation constants (log K), of the complexes formed between a number of amino acids(glycine , L-valine and L-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °C) in aqueous solutions and at natural pH of p-sulph أکثر

The formation constants (log K), of the complexes formed between a number of amino acids(glycine , L-valine and L-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °C) in aqueous solutions and at natural pH of p-sulphonato-calix [4] arene (pH=3.2) bymeans of UV-Vis spectrophotometeric technique have been investigated. At this pH the guestmolecule is in its cationic and zwitterionic forms. The results revealed that the host is q ui t ecapable of complexing with the guest in 1:1 guest-to-host ratio. Regarding the formation constantvalues, the binding selectivity of the host towards the guests proves in the order (alanine > valine >glycine). The thermodynamic parameters have been assessed and interpreted in matters of thesignificance of the various interactions responsible for the complexation. A roughly linear relationshipbetween BHo and TBSo has been observed for the studied complexes and it is discussed. تفاصيل المقالة

حرية الوصول المقاله

12 - Solution state studies on thermodynamic parameters and complexation behavior of inner transition metal ions with creatinine in aqueous and mixed equilibria
Sangita Sharma Ashish Patel Jasmin Bhalodia Jayesh Ramani

The determination of formation constants of binary inner transition metal complexes where M=Y(III) or La(III) or Ce(III) or Pr(III) or Nd(III) or Sm (III) or Gd (III) or Dy (III) or Th(IV) andL = Creatinine have been carried out using Irving–Rossotti titration tec أکثر

The determination of formation constants of binary inner transition metal complexes where M=Y(III) or La(III) or Ce(III) or Pr(III) or Nd(III) or Sm (III) or Gd (III) or Dy (III) or Th(IV) andL = Creatinine have been carried out using Irving–Rossotti titration technique in aqueous mediaat different temperatures and at ionic strength. To understand more about the nature ofequilibrium involving inner transition metals with Creatinine, the effect of dielectric constants onthe stability of these complexes at different percentage of solvent variation and at differentsolvent systems has been studied. The formation constant (logβn) have been calculated on IBMcomputer using BEST Program. Thermodynamic parameters (ΔG, ΔH and ΔS) are alsoevaluated, negative ΔG, ΔH and ΔS values indicate that complex formation is favorable atordinary temperatures. Species distribution curves of complexes have been plotted as function ofpH using Fortran IV program SPE PLOT to visualize the equilibria systems in pH range of 2-8pH. The order of stability for metals is Y < La < Ce < Pr < Nd < Sm < Gd < Dy < Th. This ordercan be explained on the basis of basicity of ligand, protonation of ligand, electronicconfiguration of metal ions, size and ionic potential of tripositive ion, charge/size ratio of metalions and species distribution diagrams. تفاصيل المقالة

فهرس المقالات Formation constant

سند

الروابط

المراكز ذات الصلة

دعامة

الصفحات الرسمية