Effects of substituents on ion-association properties. 1H n.m.r. studies of substituted pyridinium tribromo(triphenylphosphine)cobaltate(II) complexes in nitrobenzene

1980 ◽  
Vol 33 (3) ◽  
pp. 689 ◽  
Author(s):  
N Tsao ◽  
Y Lim
Keyword(s):  
Association Constant ◽  
Pyridine Ring ◽  
Complex Anion ◽  
Ion Association ◽  
Steric Effects ◽  
Triphenyl Phosphine ◽  
Isotropic Shift ◽  
Pyridinium Cations

A series of compounds containing substituted pyridinium cations and the tribromo(triphenyl-phosphine)cobaltate(II) complex anion have been prepared and studied by n.m.r. spectroscopy in nitrobenzene at 307 K. It is shown that the electronic and the steric effects of the substituents can affect the ion-association constant. From the measured isotropic shift ratios, it is concluded that two substituents at the meta positions of the pyridine ring move the complex anion away from the ring, whereas a para substituent tends to favour a geometry where the anion is tilted towards the ring.

Effects of substituents on ion-association properties. II. 1H N.M.R. studies of substituted pyridinium and tetraalkylammonium Bis(4-methylbenzene-1,2-dithiolato)cobaltate(III) in non-aqueous solvents

1981 ◽  
Vol 34 (11) ◽  
pp. 2321 ◽  
Author(s):  
N Tsao ◽  
Y Lim
Keyword(s):  
Dielectric Constant ◽  
Complex Anion ◽  
Ion Pairs ◽  
Ion Association ◽  
Ion Pair ◽  
Association Constants ◽  
Ionic Clusters ◽  
Isotropic Shift ◽  
Large Size ◽  
Pyridinium Cations

A series of nine compounds containing quaternary ammonium and substituted pyridinium cations and the bis(4-methylbenzene-1,2-dithiolato)cobaltate(III) complex anion have been prepared andtheir ion-pair properties studied by lH n.m.r. spectroscopy. Their concentration association constants in nitrobenzene at 307 K range from 9 to 20. In the pyridinium series of ion pairs, it is concludedfrom the measured isotropic shift ratios that methyl substituents at the meta and para positions favour a geometry where the anion is tilted towards the ring of the cation but the ortho substituents push the anion away from the ring. In the methyltrioctylammonium ion pair, there is linear correlation between the observed isotropic shift of the N-methyl or the N-methylene protons and the dielectric constant of the solvents (E) from 4.56 to 12.3 for the 0.06, 0.09 and 0.12 M solutions. Its implication is discussed in terms of the formation of the ionic clusters of sufficiently large size.

scholarly journals Conductometric studies of 1, 3, 5 –triazinothiocarbamide at different concentration and temperature

2021 ◽  
Vol 16 (2) ◽  
pp. 151-157
Author(s):  
DD Sonone ◽  
ME Shelke ◽  
DT Tayade
Keyword(s):  
Thermodynamic Parameters ◽  
Association Constant ◽  
Ion Association ◽  
Vital Role ◽  
Ion Pair ◽  
Pair Formation ◽  
Drug Diffusion ◽  
Ion Pair Formation

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.

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
Keyword(s):  
Association Constant ◽  
Ion Association ◽  
Dipole Interaction ◽  
Molar Conductivity ◽  
Specific Interactions ◽  
Ionic Radii ◽  
Conductance Data ◽  
Different Temperatures ◽  
Transport Behaviour ◽  
Ionic Components

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.

Raman Spectroscopic Study of the Ion Association of Lithium Sulfate Aqueous Solutions

1995 ◽  
Vol 50 (2-3) ◽  
pp. 292-300 ◽  
Author(s):  
Fernando Rull
Keyword(s):  
Aqueous Solutions ◽  
Spectroscopic Study ◽  
Association Constant ◽  
Profile Analysis ◽  
Dynamic Properties ◽  
Ion Association ◽  
Sulfate Ions ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Band Profile

Abstract A Raman spectroscopic study of Li2SO4 aqueous solutions as function of concentration and temperature was performed. The dynamic properties of the sulfate ions were studied by a band profile analysis of their internal modes using Fourier transform methods. This analysis reveals the perturbation of the SO4-2 vibrations due to ionic interactions. From the v1 (SO4-2) band profile the spectroscopic ionic association constant was calculated in the range from 5 to 80 °C. The large difference found between the values thus obtained for the association constant and the values obtained from macroscopic measurements is interpreted, assuming that Raman spectra reflect only the short-range forces acting on the ions. Using the Bjerrum equation to calculate the contribution for the long-range forces, good agreement is found between the spectroscopic and macroscopic results.

scholarly journals Crystal structure of tris[4-(dimethylamino)pyridinium] tris(oxalato-κ2O,O′)chromate(III) tetrahydrate

2015 ◽  
Vol 71 (11) ◽  
pp. 1408-1410 ◽  
Author(s):  
Noé Makon ma Houga ◽  
Frédéric Capet ◽  
Justin Nenwa ◽  
Gouet Bebga ◽  
Michel Foulon
Keyword(s):  
Complex Anion ◽  
Crystal Packing ◽  
Rotation Axis ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Additional Stabilization ◽  
Pyridinium Cations

In the title hybrid salt, (C7H11N2)3[Cr(C2O4)3]·4H2O, the central CrIIIion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2−) ligands in a slightly distorted octahedral coordination sphere. The Cr—O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O—Cr—O angles range from 82.11 (6) to 93.41 (5)°. The 4-(dimethylamino)pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N—H...O and O—H...O hydrogen bonds link the cations and anions into a three-dimensional network. π–π interactions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å.

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