Calculation of Electrochemical Reorganization Energies for Redox Molecules at Self-Assembled Monolayer Modified Electrodes

Abstract

Electrochemical electron transfer reactions play an important role in energy conversion processes with many technological applications. Electrodes modified by self-assembled monolayers (SAMs) exhibit reduced double layer effects and are used in molecular electronics. An important quantity for calculating the electron transfer rate constant is the reorganization energy, which is associated with changes in the solute geometry and the environment. In this Letter, an approach for calculating the electrochemical reorganization energy for a redox molecule attached to or near a SAM modified electrode is presented. This integral equations formalism polarizable continuum model (IEF-PCM) approach accounts for the detailed electronic structure of the molecule, as well as the contributions from the electrode, SAM, and electronic and inertial solvent responses. The calculated total reorganization energies are in good agreement with experimental data for a series of metal complexes in aqueous solution. This approach will be useful for calculating electron transfer rate constants for molecular electrocatalysts.

Nature of the First Electron Transfer in Electrochemical Ammonia Activation in a Nonaqueous Medium

“…18 Through this method, the reorganization energy for ammonia oxidation (Equation 3) was calculated to be 1.94 eV. This value is significantly larger than many experimentally determined reorganization energies for common outer-sphere reactions, 18,32,33 such as that of ferrocyanide oxidation in water ( = 0.99 ), 33 and explains the low transfer coefficient observed in the ammonia oxidation reaction ( Figure 5b).…”

Electrochemical kinetics as a function of transition metal dichalcogenide thickness

“…The overlap integrals for anodic and cathodic processes, as described in Eq.1 and Eq.2, were calculated by numerical integration, obtaining two waveforms (for anodic and cathodic processes), which describe the ratio of the overlap of the reacting redox species as a function of the applied potential. The waveforms, displayed in Figure S15, range between 0 and 1 and assume a metallic electrode with flat DOS and reorganization energy (λ) for [Ru(NH3)6] 3+/2+ of 1 eV [45,47,48]. Thus, the total current can be expressed as:…”

ANI-1: an extensible neural network potential with DFT accuracy at force field computational cost

“…ML methods have been successfully applied in a variety of applications in chemistry, including the prediction of reaction pathways, 18 QM excited state energies, 19 formation energies, 20 atomic forces, nuclear magnetic resonance chemical shifts, 21 and assisting in the search of novel materials. 22 ML potentials have shown promise in predicting molecular energies with QM accuracy with a speed up of as much as 5 orders of magnitude.…”