Electrochemical and Computational Study of Ion Association in the Electroreduction of PW₁₂O₄₀^3–

Abstract

Insights into ion pairing effects on the redox properties of the Keggin-type polyoxotungstate PW12O40 3are gained by combining electrochemical experiments and density functional theory (DFT) calculations. Such effects have been reported to affect the performance of these species as molecular electrocatalysts.Experimental square wave voltammetry (SWV) of the two-electron reduction of PW12O40 3in acetonitrile evidences that the reduced forms PW12O40 4and PW12O40 5can be significantly stabilized by ion association. The strength and stoichiometry of the corresponding aggregates are estimated as a function of the nature of the cation (lithium, sodium and tetramethylammonium) and the oxidation state of the polyoxometalate. The results obtained in combination with DFT enable us to examine the roles of the cation solvation and the charge number and distribution of the polyanions.

Unveiling KuQuinone Redox Species: An Electrochemical and Computational Cross Study

“…Similarly, in CH 2 Cl 2 /TBAPF 6 , ion pairing between KuQ 3 · – and supporting electrolyte cations occurs, thus inhibiting reversibility. 22 , 23 …”

“…Similarly, in CH 2 Cl 2 /TBAPF 6 , ion pairing between KuQ 3•− and supporting electrolyte cations occurs, thus inhibiting reversibility. 22,23 Therefore, tetrabutylammonium perchlorate (TBAP) has been chosen as the supporting electrolyte for further experiments. Previous works demonstrated that solvent polarity affects the acid−base equilibrium in KuQs.…”

“…It can be assumed that in CH 2 Cl 2 /TFAB, an intimate ion pair between KuQ 2– and tetrabutylammonium ions forms, leading to stable species, which do not undergo further reduction. Similarly, in CH 2 Cl 2 /TBAPF 6 , ion pairing between KuQ 3 · – and supporting electrolyte cations occurs, thus inhibiting reversibility. , …”

Redox-inactive ions control the redox-activity of molecular vanadium oxides

“…Previous work had demonstrated that the presence of different cations can lead to signicant shis of the redoxprocesses in polyoxometalates. 29,50 To explore this behaviour for {Ca 2 V 12 }, we performed cyclic voltammetry using deaerated, anhydrous DMF containing LiPF 6 (0.1 M) as the electrolyte (see the ESI, Fig. S11 †).…”

Electrical Conductance And Theoretical Study Of Glutamic Acid In Different Solvents at 310.16k

“…In particular, in recent years, the solventand ion-related effects on polyelectrolytes have drawn significant interest. Previous atomistic MD simulations, for example, showed that the behavior of molecular solving greatly influences the sum of dissociated counterions and hence the resulting conformational behaviour of repulsive electrostatic interactions or charge screening effects along the polyelectrolyte backbone [9,14,15]. The presence of the polyelectrolyte as expressed by local dielectric constant changes, asymmetry effects of charge hydration, or modified charge transfer mechanisms [16][17][18], affects the molecular structure of the solvent molecules.…”