scholarly journals Thermodynamic Studies of Complexes of Amlodipine Besylate with Ni2+, Mg2+, Co2+ and Ca2+ cations in pure and in mixed binary solvent systems at 303.15, 313.15 and 323.15 K by Conductometric Method

2020 ◽  
Vol 13 (1) ◽  
pp. 206-216
Author(s):  
Dhruvi. R. Mehta ◽  
Raviprakash S. Chandra ◽  
M. M. Maisuria

The present work relates to the complexation reaction between Amlodipine Besylate[AML] with Ni2+, Mg2+, Co2+ and Ca2+ cation in dimethylsulfoxide (DMSO), pure methanol (MeOH) and their binary mixtures(DMSO-MeOH and DMSO-Water) by conductometric method. The conductance data show that the stoichiometry of the complexes formed between AML with Ni2+, Mg2+, Co2+ and Ca2+ cation in pure DMSO, pure MeOHas well as in the binary solvent mixtures was 1:1. The stability of AML complexes with Ni2+ , Mg2+, Co2+ and Ca2+ metal ion was observed to be sensitive to the nature of the solvent system. In case of DMSO-Water binary solvent systems there was a linear change in LogKf values but in case of DMSO-MeOH binary solvent systems non linear change in LogKf values observed.The negative values of ΔG0 show that the reaction is spontaneous and ability of the AML ligand to form stable complexes. However, the result shows positive value of ΔH0 which indicates that enthalpy is not driving force for the formation of the complexes. Furthermore, the positive value of ΔS0 indicates that entropy is a driving force for the complexation. The values of ΔH0 and ΔS0 for formation of the complexes were obtained from temperature dependence of the stability constants.

2019 ◽  
Author(s):  
Chem Int

Stability constants are measured for complexes of Cd2+, Ni2+, Cu2+ and Co2+ with pyridine-2,6-dicarboxylic acid(PDA) in water, methanol and water-methanol binary solvent systems at 298.15, 308.15 and 318.15 K by conductometric method. The result shows that the stoichiometry of the complexes of PDA with all metals in all binary solvent systems is 1:2 [ML2]. The logKf values of PDA-M2+ complexes in H2O-MeOH binary solvent systems increase with increasing % of MeOH and temperature. The ΔH0 and ΔS0 of the complexation reaction in the different H2O-MeOH binary solvent systems were evaluated by the temperature dependence of the formation constants using a linear least square analysis according to van’t Hoff equation.


2014 ◽  
Vol 79 (10) ◽  
pp. 1263-1277
Author(s):  
Rashmidipta Biswas ◽  
Dhiraj Brahman ◽  
Biswajit Sinha

The complexation reaction between N-salicylidene-2-aminophenol, abbreviated as SAP, with Cu2+ ion was studied in binary mixtures of methanol and 1,4-dioxane by using conductometric and spectrophotometric method at different temperatures. The stability constants (Kf) for the 1:1 complex, Cu2+-SAP, were calculated from computer fitting of absorbance and molar conductance data against various mole ratios (cM:cL or cL:cM) in different binary solvent mixtures. A non-linear behaviour was observed for the variation of logKf for the complex against the solvent compositions. Various thermodynamic parameters (?H, ?S and ?G) for the formation of Cu2+-SAP complex were determined from the temperature dependence of stability constants (Kf). The overall results showed that the complexation reaction is entropy driven and is affected by the nature and composition of the mixed solvents.


1997 ◽  
Vol 12 (4) ◽  
pp. 1062-1068 ◽  
Author(s):  
Jau-Ho Jean ◽  
Shun-Fen Yeh ◽  
Chi-Jen Chen

The adsorption of poly(vinyl butyral) (PVB) on NiCuZn ferrite powder in binary solvent systems of 1-butanol and toluene has been investigated. The adsorption isotherms of different PVB's on ferrite powder from various solvent mixtures follow closely the Langmuir monolayer types and can be explained by adsorption competition between solvents and PVB. A relatively poor solvent for PVB increases its adsorption on ferrite powder and thus improves the dispersion of the powder in the nonaqueous suspension. The adsorbance of PVB increases with increasing hydroxyl content in PVB suggesting that PVB is bonding strongly to the protruding surface hydroxyl groups on ferrite powder.


2014 ◽  
Vol 79 (5) ◽  
pp. 565-578 ◽  
Author(s):  
Rashmidipta Biswas ◽  
Dhiraj Brahman ◽  
Biswajit Sinha

The complexation reaction between salicylaldehyde thiosemicarbazone, abbreviated as STSC, with Cu2+ ion was studied in the binary mixtures of methanol + 1,4-dioxane binary by using UV-Visible spectrophotometric and conductometric methods at different temperatures. The formation constants (Kf) for the 1:1 complex, Cu2+-STSC, were calculated from computer fitting of the absorbance and molar conductance data against various mole ratios (cM:cL or cL:cM) in different binary solvent mixtures. A non-linear correlation was observed for the variation of logKf for the complex against the solvent compositions. Various thermodynamic parameters (?H, ?S and ?G) for the formation of Cu2+-STSC complex were also determined from the temperature dependence of the stability constants (Kf). The results showed that the complexation reaction is affected by the nature and composition of the mixed solvents.


2020 ◽  
Vol 22 (19) ◽  
pp. 10995-11011 ◽  
Author(s):  
Dilek Yalcin ◽  
Andrew J. Christofferson ◽  
Calum J. Drummond ◽  
Tamar L. Greaves

In this study, we have investigated the solvation properties of binary mixtures of PILs with molecular solvents. The selected binary solvent systems are the PILs ethylammonium nitrate (EAN) and propylammonium nitrate (PAN) combined with either water, methanol, acetonitrile or DMSO.


1981 ◽  
Vol 34 (5) ◽  
pp. 933 ◽  
Author(s):  
S Balakrishnan ◽  
AJ Easteal

Values of the empirical solvent polarity parameters ET and Z have been determined as a function of composition for the binary solvent systems 1,2-dibromoethane + 1,2-dibromopropane, acetone + chloroform, acetone + ethanol, ethanol + chloroform and acetone + dichloromethane. For the 1,2-dibromoethane + 1,2-dibromopropane system both ET and Z are accurately linear (i.e. additive) functions of composition. For the other systems both parameters vary with composition in a strongly non-additive manner, and the deviations from additivity are interpreted in terms of intermolecular interactions. For these systems, in general ET and Z are not highly correlated, and neither parameter is highly correlated with other macroscopic properties or parameters derived from them.


Author(s):  
Ying Guo ◽  
Hui He ◽  
Haishuang Huang ◽  
Jingxuan Qiu ◽  
Jiaming Han ◽  
...  

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