Viscometric and Conductometric Studies of Solvation Behaviour of Tetraalkylammonium Salts in the Binary Mixtures of Dimethylsulfoxide and Methanol at 298.15 K

Molar conductance and viscosity of some tetraalkylammonium perchlorates (R4NClO4 where R = Methyl, Ethyl, Propyl, Butyl) have been measured in the concentration range (30–500) × 10−4 mol kg−1 at 298.15 K in the binary mixtures of dimethylsulfoxide (DMSO) + methanol (MeOH) containing 0, 20, 40, 50, 60, 80 and 100 mol% methanol. Conductance data has been analyzed using the Shedlovsky equation and the viscosity data by Jones-Dole equation. The limiting ionic conductances ($\lambda_{\pm}^{o}$) were used to calculate the solvated radii (ri) of the ions. The A and B coefficients of the Jones-Dole equation are positive in all salts. The A coefficients are in reasonable good agreement with the limiting theoretical values (Aη) calculated using Falkenhagen-Vernon equation. The variation of the ionic B± coefficients as well as the actual solvated radii (ri) with solvent composition in DMSO + MeOH mixtures show the preferential solvation of tetraalkylammonium ions by MeOH and MeOH-rich region of the mixtures. The tetraalkylammonium ions exhibit solvation in the order Me4N+ > Et4N+ > Pr4N+ > Bu4N+.

Bulky cations greatly increase the turnover of a native hammerhead ribozyme

Large tetraalkylammonium ions increase the turnover rate of the ribozyme derived from an intronic ribozyme in the human genome. The rate can be enhanced by more than a hundred-fold at the optimal concentrations of Mg2+ and TPeA ions.

Separation of asparagine, valine and tetraethylammonium ions overlapping in an ion mobility spectrum by clustering with methanol introduced as a modifier into the buffer gas

We introduced methanol into the buffer gas of an ion mobility spectrometer-mass spectrometer and mobilities changed depending on ion structures; baseline separation of valine, asparagine, and tetraalkylammonium ions was achieved.

Increased ion conduction in dual cation [sodium][tetraalkylammonium] poly[4-styrenesulfonyl(trifluoromethylsulfonyl)imide-co-ethylacrylate] ionomers

Three dual-cation polymeric ionomers that contain tetraalkylammonium ions and sodium ions have been synthesized and exhibited higher conductivity than the analogous single sodium ion polymers.