Transport Behaviour of Ions in N,N-Dimethylformamide and Dimethyl Sulfoxide at Different Temperatures. Conductance Studies

1995 ◽  
Vol 60 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Mohinder S. Chauhan ◽  
Manita Sharma ◽  
Sanjay Gupta ◽  
K. Ashwini ◽  
Suvarcha Chauhan

Molar conductivities of Bu4NBPh4, Bu4NNO3, LiNO3, NaNO3, KNO3 and AgNO3 have been reported in pure DMF and DMSO in the temperature range from 20 to 45 °C. The conductance data have been analyzed in terms of limiting molar conductivity Λ0 and ion-association constant KA. Separation of Λ0 into ionic components Λi 0 has been carried out on the basis of Bu4NBPh4 assumption in order to calculate the effective ionic radii ri in DMF and DMSO. Examination of ri values of K+ and Ag+ ions as a function of temperature revealed some specific interactions of Ag+ ion with DMF and DMSO. In DMSO electrostatic ion-dipole interaction of Li+, Na+ and K+ ions is found to be somewhat modified due to dipole-dipole interaction.

1992 ◽  
Vol 57 (10) ◽  
pp. 2078-2088 ◽  
Author(s):  
Mohinder S. Chauhan ◽  
Kishore C. Sharma ◽  
Sanjay Gupta ◽  
Suvarcha Chauhan ◽  
Vijay K. Syal

Molar conductances and viscosities of Bu4NBPh4, NaBPh4 and R4NBr (R ethyl, propyl and butyl) at 35 °C in acetonitrile (AN), dimethylsulfoxide (DMSO) and their binary mixtures have been reported. The conductivity data has been analysed by the Shedlovsky conductance equation and viscosity data by the Jones-Dole equation. Resolution of limiting molar conductivity (Λ0) and viscosity B coefficient of electrolytes into their ionic components have been achieved by the reference salt method. Viscosity A coefficients have been compared with theoretical Aη coefficients. Derived conductance and viscosity parameters have been discussed in terms of the ion-solvent interaction.


2021 ◽  
Vol 16 (2) ◽  
pp. 151-157
Author(s):  
DD Sonone ◽  
ME Shelke ◽  
DT Tayade

Conductivity plays vital role in drug diffusion. Thermodynamic parameters affected by substituents of drug. Thermodynamic parameters of 1, 3, 5 –triazinothiocarbamide (1a) have been investigated by using conductometrically carried out at different molar concentrations. This work highlights investigation of G, K and µ values. The thermodynamic parameters viz. ΔH, ΔS and ∆G for ion pair formation determine from the value of ion association constant. This technique is suitable and accurate to study of pharmokinetics and pharmodynamics parameters.


Author(s):  
Seplapatty Kalimuthu Periyasamy ◽  
H. Satham Hussain ◽  
R. Manikandan

The kinetics of Oxidation of Phenol and aniline by quinolinium Chlorochromate (QCC) in aqueous acetic acid medium leads to the formation of quinone and azobenzene respectively. The reactions are first order with respect to both Phenol and aniline. The reaction is first order with respect to quinolinium chlorochromate (QCC) and is catalyzed by hydrogen ion. The hydrogen-ion dependence has the form: kobs = a+b [H+]. The rate of oxidation decreases with increasing dielectric constant of solvent, indicating the presence of an ion-dipole interaction. The reaction does not induced the polymerization of acrylonitrile. The retardation of the rate by the addition of Mn2+ ions confirms that a two electron transfer process is involved in the reaction. The reaction rates have been determined at different temperatures and the activation parameters have been calculated. From the above observations kinetic results a probable mechanism have been proposed.


1988 ◽  
Vol 66 (7) ◽  
pp. 1720-1727 ◽  
Author(s):  
Auaz Ahmad Ansari ◽  
M. R. Islam

Electrical conductivities of Me4NBr, Et4NBr, Pr4NBr, Bu4NBr, and Bu4PBr have been measured in isopropanol + water (2-PrOH + H2O) mixtures covering the approximate range of dielectric constant (71.40 ≥ D ≥ 19.40) at 25 °C. The conductance data have been analysed by using the Fuoss-1978 (F78) conductance equation and the results compared with those obtained from the Fuoss–Onsager–Skinner (FOS) equation. The values of the limiting equivalent conductance, Λ0, the association constant, KA, and the distance of ion-size parameter [Formula: see text] are computed from these data. A better fit of the conductance data was provided by the F78 equation. Ion–solvent interactions and effective sizes of tetraalkylammonium ions are also discussed in order to understand the magnitude of the ionic association. The overall association behaviour of these salts has been found to increase with decrease in dielectric constant of the medium.


1988 ◽  
Vol 66 (5) ◽  
pp. 1223-1228 ◽  
Author(s):  
Aijaz Ahmad Ansari ◽  
M. R. Islam

The molar conductivities of Pr4NBr, Bu4NBr, Pr4NI, and BU4NI have been measured in tert-butanol–water (t-BuOH–H2O) mixtures (61.30 ≥ D ≥ 16.50) over the maximum concentration range (2 × D3 × 10−7 mol dm−3) along with the densities and viscosities of the solvent mixtures at 25 °C. The conductance data have been analysed by using the Fuoss-1978 (F78) conductance equation and the results compared with the values obtained from the Justice (J), Pitt's (P), and Fuoss–Onsager–Skinner (FOS) equations. Molar conductivities at infinite dilution (Λ0), the thermodynamic ion association constants (KA) and the distance or ion-size parameters (R0 or a0) are evaluated from these data. The F78 equation fitted the data better and yielded KA and R values which are in accord with the ion-association theories. The interpretation of these parameters is discussed to provide some insight on the magnitude of the ionic association and the ion–solvent interaction.


1978 ◽  
Vol 11 (2) ◽  
pp. 103-178 ◽  
Author(s):  
M. Thomas Record ◽  
Charles F. Anderson ◽  
Timothy M. Lohman

The purpose of this review is to examine the various effects of low- molecular-weight electrolytes on the associations and interactions of proteins and nucleic acids. Our primary interest is in general electrostatic effects, rather than chemical effects (specific interactions) of particular ions (e.g. transition metals, protons). We consider those interactions in which a variation in salt concentration has a significant effect on the macromolecular equilibrium, and analyse the effects of salt in these situations in terms of (i) direct participation of ions in the biopolymer reaction, (ii) Debye—Hückel screening by salt ions of the charge interactions on the biopolymers, and (iii) the reduction in water activity brought about at high salt concentrations.


2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Kosrat N. Kaka ◽  
Anis A. Al-Najar ◽  
Wali M. Hamad

The audio electrical conductances of aqueous solutions of magnesium, manganese II, barium, and copper succinates have been measured at various temperatures in the range of 298.15 K to 313.15 K, using an audio frequency conductance bridge. The evaluation of conductance data was carried out by minimisation technique using the theoretical equations of the complete and modified forms of Pitts (P) and Fuoss-Hsia (F-H), each a three-parameter equation, association constant (KA), molar conductance (Λm), and distance parameter (a). Quantitative results showed that these salts do not behave as “strong” electrolytes, and that their dissociations are far from complete. The abnormally low conductances of these electrolytes are not due to the presence of electrically neutral molecules but to the ion-pair formation. The Walden product values, as well as the standard thermodynamics functions (ΔH∘,ΔG∘,ΔS∘) for the association reaction at the four temperatures studied, have been evaluated.


2003 ◽  
Vol 217 (6) ◽  
pp. 739-750 ◽  
Author(s):  
Dip Singh Gill ◽  
Vivek Pathania ◽  
Bal Krishan Vermani ◽  
Raj Pal Sharma

AbstractMolar conductances of a large number of copper(I) and cobalt(III) complexes, behaving as strong 1:1 electrolytes, have been measured in acetonitrile (AN) and n-butyronitrile (n-BTN) at 298.15K. The conductance data have been analyzed by the Shedlovsky method to evaluate Λ0 and KA values of these electrolytes. Limiting ion conductances (λi0) for various ions in AN have been calculated by using transference number data. In n-BTN, where no transference number data is available, such values have been calculated by an indirect method using Bu4NBPh4 as a reference electrolyte. The actual ionic radii (ri) for various ions in solution have been calculated using a modified form of Stokes’ law. The ionic radii (ri) for various complex ions have been compared with the ionic radii of two reference ions, Bu4N+ and Ph4B−, which are not solvated in dipolar aprotic solvents, to throw light on the solvation behaviour of these complex ions.


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