Metal ion association in alcohol solutions. III. Erbium chloride in aqueous methanol

1974 ◽  
Vol 78 (4) ◽  
pp. 424-428 ◽  
Author(s):  
Jeffry Reidler ◽  
Herbert B. Silber
Keyword(s):  
Metal Ion ◽  
Ion Association ◽  
Aqueous Methanol ◽  
Erbium Chloride

Metal ion association in alcohol solutions—I

1974 ◽  
Vol 36 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Jeffry Reidler ◽  
Herbert B. Silber
Keyword(s):  
Metal Ion ◽  
Ion Association

Solvent-dependent circular dichroism of trans-disubstituted Bis(R-propane-1,2-diamine)cobalt(III) complexes

1977 ◽  
Vol 30 (10) ◽  
pp. 2115 ◽  
Author(s):  
CJ Hawkins ◽  
GA Lawrance ◽  
RM Peachey
Keyword(s):  
Circular Dichroism ◽  
Metal Ion ◽  
Ion Association ◽  
Positive Contribution ◽  
Circular Dichroism Spectra ◽  
Hydrogen Bond Formation ◽  
Rotational Strength ◽  
Solvent Dependence ◽  
Halide Salts ◽  
Circular Dichroïsm

The circular dichroism spectra of trans-disubstituted bis(R-propane- 1,2-diamine)cobalt(III) complexes are reported for an extended series of solvents. The observed variations in the spectra of the dichloro and dibromo complexes are analysed in terms of stereoselective solvation at the diamine N-H protons, and also the ion association between the complexes and their counter-ions. The solvation of these dihalo complexes, which was studied by p.m.r., showed a preference for hydrogen-bond formation with the equatorial N-H protons, rendering the donor nitrogens asymmetric and thus introducing a new source of dissymmetry close to the metal ion chromophore. This affected a decrease in the positive rotational strength of the 1A1g → 1Eg (D4h) transition, and a positive contribution to the rotational strength of the 1A1g → 1A2g (D4h) component. Ion association of the dihalo complexes was evaluated by a comparison of the circular dichroism of the tetraphenylborate and halide salts. ��� The tendency for ion association was much greater for the tripositive diammine complex. However, stereospecific solvation was of little importance and the circular dichroism spectra did not show any marked solvent dependence for the tetraphenylborate salt.

scholarly journals When spectroscopy fails: The measurement of ion pairing

2006 ◽  
Vol 78 (8) ◽  
pp. 1571-1586 ◽  
Author(s):  
Glenn Hefter
Keyword(s):  
Metal Ion ◽  
Chemical Speciation ◽  
Ion Pairs ◽  
Ion Association ◽  
Ion Pair ◽  
Association Constants ◽  
Spectroscopic Techniques ◽  
Association Equilibria ◽  
Solvent Molecules ◽  
Contact Ion Pairs

Spectroscopic techniques such as UV/vis, NMR, and Raman are powerful tools for the investigation of chemical speciation in solution. However, it is not widely recognized that such techniques do not always provide reliable information about ion association equilibria. Specifically, spectroscopic measurements do not in general produce thermodynamically meaningful association constants for non-contact ion pairs, where the ions are separated by one or more solvent molecules. Such systems can only be properly quantified by techniques such as dielectric or ultrasonic relaxation, which can detect all ion-pair types (or equilibria), or by traditional thermodynamic methods, which detect the overall level of association. Various types of quantitative data are presented for metal ion/sulfate systems in aqueous solution that demonstrate the inadequacy of the major spectroscopic techniques for the investigation of systems that involve solvent-separated ion pairs. The implications for ion association equilibria in general are briefly discussed.

Thermodynamics of Ion-Association of NaClO4in Aqueous-Methanol and Aqueous-Glycerol Using Conductance Measurements

1988 ◽  
Vol 35 (5) ◽  
pp. 337-344 ◽  
Author(s):  
Mostafa M. Emara ◽  
Hassan A. Shehata ◽  
Sayed H. El Nkhaily
Keyword(s):  
Ion Association ◽  
Aqueous Methanol

Investigations of polyelectrolyte-transition metal ion association in mixed solvents

1991 ◽  
Vol 27 (2) ◽  
pp. 179-184 ◽  
Author(s):  
S. K. Chatterjee ◽  
F. H. Rajabi ◽  
B. V. Farahani ◽  
N. Chatterjee
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Mixed Solvents ◽  
Ion Association ◽  
Transition Metal Ion

Metal ion association in alcohol solutions—VIII

1976 ◽  
Vol 38 (11) ◽  
pp. 2053-2057 ◽  
Author(s):  
Herbert B. Silber ◽  
Arthur Pezzica
Keyword(s):  
Metal Ion ◽  
Ion Association
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