A Study on the Solvation Phenomena of Some Sodium Salts in 1,2-Dimethoxyethane from Conductance, Viscosity, Ultrasonic Velocity, and FT-Raman Spectral Measurements

Abstract

Electrical conductances, viscosity, apparent molar adiabatic compressibilities and Fourier transform (FT)-Raman spectra of sodium perchlorate (NaClO 4 ), sodium tetrafluoroborate (NaBF 4 ), and sodium tetraphenylborate (NaBPh 4 ) in 1,2-dimethoxyethane have been reported. All these electrolytes are found to be strongly associated in this solvent medium. Both ion pairs and triple ions are found to be formed though an overwhelming fraction of each of these electrolytes exists as ion pairs. For NaClO 4 , the solvent-separated ion pairs predominate over the contact species. For NaBF 4 and NaBPh 4 , on the other hand, the contact species are also formed in significant amounts. FT-Raman studies indicate the presence of "spectroscopically free" ClO 4 -, BF 4 -, and BPh 4ions in 1,2-dimethoxyethane solution. The ClO 4ion is found to be significantly solvated, whereas BF 4and BPh 4ions are poorly solvated in DME solution.

Unique Behavior of Dimethoxyethane (DME)/Mg(N(SO2CF3)2)2 Solutions

“…In particular, Raman spectroscopy is very sensitive to molecular conformation and, under favorable conditions, can be used for clear identification of the different conformers in mixtures . Importantly, each conformer is characterized by distinct values of its properties such as its dipole moment, chelating capabilities, and molecular excess volume, making it a useful indicator of the state of the solution. ,, For example, the conformers’ distribution was found to be strongly dependent on the phase (liquid or gas), the presence of other components in the mixtures, and the temperature. ,, …”

“…4,17,18 For example, the conformers' distribution was found to be strongly dependent on the phase (liquid or gas), the presence of other components in the mixtures, and the temperature. 7,15,19 The other component in the solutions explored in this work, MgTFSI 2 , is a unique magnesium salt. Because of its chargedissipation capabilities, the bulky TFSI anion forms a highly soluble salt in many organic solvents, despite the small doubly charged magnesium cation.…”

A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

“…Fuoss relation was used to evaluate limiting molar conductance ), association constants ), and co-sphere diameter (R) for ion-pair formation in the mixed solvent systems. The measurements of electrical conductance of sodium per chlorate (NaClO 4 ), sodium tetrafluoroborate (NaBF 4 ) and sodium tetraphenyl borate (NaBPh 4 ) in 1,2-dimethoxythane by Pitchi J Victor et al [26] reveals that ions are solvated to greater extent as compared to and ions in the solvent. Though both ion-pairs and triple ions form, formation of ion pairs dominates over the formation of triple ions.…”

Micro-Raman analysis of association equilibria in supersaturated NaClO4 droplets

“…As droplets become more and more concentrated with the decrease of RH, a complex ion aggregates component commonly appears. 12,28 For this band component, the peak position and its FWHM are fixed in our fitting process, as for the other components.…”

“…À represents the solvent-shared ion pair, Na + ClO 4 À represents the contact ion pair and (Na + ClO 4 À ) 2 refers to complex ion aggregates. 12,28 Here we use micro-Raman technique to study the complex associations that occur in supersaturated solutions in single NaClO 4 droplets deposited on a quartz substrate. The diameter of the deposited droplets is from 5 to 20 microns, and the mass is on the order of a nanogram.…”