The β-hydroxyethyl radical as a model system for two-pathway electroreduction in the presence of proton donors

Thermodynamic and kinetic characteristics of intermediates of electrode reactions: A comparative investigation of a number of alkylaryl and alkyl halide radicals by the laser photoemission methods

“…Following such a correction, the Tafel plots practically merged, which points to the closeness of values of E 0 and τ X in these solvents. 7 As far as radicals of the second group are concerned, the dependence of the rate of their electroreduction on pH is observed in acidic and, every now and then, in weakly alkaline solutions as well [39][40][41][42][43]46], and, more likely than not, the final product is RH [1,23,24] .…”

“…The intermediates that were investigated in this work had been generated by a photoemission current I P of solvated (hydrated) electrons homogeneously captured by compound RX [19][20][21][22][23][24][39][40][41][42][43][44][45][46]-steps (a) and (b) in Scheme 1; such a technique of generation is similar to 4 The authors thank S.V. Kurmaz for help in these measurements.…”

Thermodynamic and kinetic characteristics of intermediates of electrode reactions: Determination by direct and combined electrochemical methods

“…A group of methods of laser photoemission (LPE), 2 which were designed in the 1960s to 1990s (see, for example, [1,33,85,86,89]) and the references presented there, getting technically ever more perfect [1,32,39,40,83,, continues to be actively used for both the investigation of irreversible and quasi-reversible electrode reactions involving intermediates in aprotic and protogenic media [1,39,40,84,87,88,[98][99][100][101][102][103][104][105][106][107][108][109][110][111] and the investigation of redox properties of intermediates in aprotic media [1,[94][95][96][97].…”

“…4a, curve 1). The situation turns more involved in the presence of a slow chemical τ X 1 -step, for example, the dissociation of radical anions [87,88,122] or the formation/dissociation of a metastable complex of radicals with a donor/acceptor of protons [32,[100][101][102], which is possible in both protic and aprotic media; the latter case is presented in Fig. 4a, curve 2, for a metastable complex of radical β-hydroxyethyl with H 3 O + [100].…”

“…(a) Tafel plots for irreversible reduction of (1) trifluoromethyl ( ) radical (data of[96,106,111]) and (2) β-hydroxyethyl radical (data of[100]); supporting electrolyte-aqueous solution of 0.5 M KCl with addition of buffer solutions, with the following values of pH: (1) 4.8-9.6 and (2) 3.6; an Hg electrode; and (b) the E 1/2 ,Ω dependences for a trifluoromethyl radical, obtained (1, 2, 2') experimentally and(3)calculated: (1) data of measurements of kinetics in a coulostatic regime and (2, 2') data of TRV; calculation parameters: W d = 10 3 s -1 , = 10 9 s -1 , τ R = 10 -3 s, and τ X = 10 -2 s; points 2 and 2' correspond to different experimental series; DMSO or DMF + 0.4 M LiClO 4 ; an Hg electrode; vertical dashed lines mark the range of scatter of E 0 (see text for explanations).…”