Pulse voltammetric and NMR investigations of thionyl chloride in N,N-dimethylformamide

Abstract

Normaland reverse-pulse voltammetry was used to investigate both the reduction and oxidation of SOCl2 at glassy carbon electrodes in jV,7V-dimethylformamide (DMF) with tetrabutylammonium hexafluorophosphate supporting electrolyte. NMR spectroscopy was used to probe for interactions between SOCl2 and DMF. NMR spectra and the quantitative treatment of normaland reverse-pulse voltammograms gave evidence for the displacement of Cl" in SOCl2 by DMF. The species SO2"1", solvated by DMF, and Cl" are responsible for the reduction and oxidation currents, respectively. The species S02+ is reduced via a two-electron process to "SO". Analyses of normal-pulse voltammograms for the S02+ reduction indicate that the rate-determining step is a one-electron transfer, and there is no evidence for an intermediate in the overall electroreduction.

Stripping chronopotentiometry at scanned deposition potential (SSCP). Part 4. The kinetic current regime

“…5, the direct dissociation of the Cd-NTA complex via Eq. (20) becomes slower than the acid-assisted path of Eq. (21), the rates being k 1 in the range 1-3 s À1 , and k 2 6.5 Â 10 4 -1.5 Â 10 6 dm 3 mol À1 s À1 [30].…”

“…All curves correspond to HMDE conditions with a t d of 300 s. Data correspond to (i) a CdL complex that is labile, m, or quasi-labile, n (calculated using the same parameters as given in Fig. 2), (ii) a redox reaction that is reversible, d, or irreversible, s (calculated for conditions relevant for Zn [20][21][22][23]: a ¼ 0:3, k 0 ¼ 1 Â 10 À5 s À1 , D ¼ 7:8 Â 10 À10 m 2 s À1 [24]) and (iii) a metal-only curve, n, and in the presence of a heterogeneous ligand, Ã (data are experimental results for Cu(II) in the presence of humic acid, 15 mg dm À3 ; see [11] for details). Curves are shown for the labile case (j) and the kinetic case with k a ¼ 10 10 (Ã) and 10 9 dm 3 mol À1 s À1 (n).…”

Isolation and Characterization of a Non‐Rigid Hexamethylbenzene–SO2+ Complex

“…[25] Later reports claimed the existence of solvated SO 2+ from the reaction of thionyl chloride and silver salts in acetone [26] and from autodissoziation of thionyl chloride in DMF. [27] Under strongly ionizing conditions, SO 2+ has been detected in the gas phase. [28] Although the detection of the C6(CH3)6SO 2+ adduct is unprecedented, the general structure is not.…”

Stripping chronopotentiometry at scanned deposition potential (SSCP). Part 6: Features of irreversible complex systems

“…Values reported for k 0 range from 2 to 5 · 10 À4 m s À1 in 0.1 mol dm À3 NO À 3 (i.e., reversible [20][21][22][23]), and from 2.8 to 4.2 · 10 À5 m s À1 in 1.0 mol dm À3 NO À 3 or ClO À 4 (i.e., quasi-reversible) [20,21,[23][24][25], with a % 0.3 in all cases. The charge transfer rates at an ionic strength of 1.0 mol dm À3 fall within the range in which the shape of the SSCP wave is sensitive to electrode size and deposition time, as demonstrated previously [8].…”