arXiv subjects

Leonardo Coello Escalante

Publications and source records attributed to Leonardo Coello Escalante.

3 recordsLinked to original sources

arXiv2026

Solvent Effects on Triplet Yields in BODIPY-Based Photosensitizers

We employ molecular dynamics simulations and quantum rate theories to elucidate the complex condensed-phase dynamics underpinning triplet-state formation in organic photosensitizers. Using models informed by first-principles calculations complete with a molecular representation of solvents of different polarities, we elucidate the interplay of the internal and environmental interactions underlying triplet yield. We find that triplet yields depend sensitively on the dielectric stabilization of the charge transfer intermediate that facilitates a transition into the triplet manifold. Our results illustrate the importance of molecularly detailed models in understanding the excited-state internal charge-transfer dynamics of photochemically-relevant organic molecules.

physics.chem-ph↗

arXiv2025

Electronic origin of reorganization energy in interfacial electron transfer

Electron transfer (ET) reactions underpin energy conversion and chemical transformations in both biological and abiological systems. The efficiency of any ET process relies on achieving a desired ET rate within an optimal driving force range. Marcus theory provides a microscopic framework for understanding the activation free energy, and thus the rate, of ET in terms of a key parameter: the reorganization energy. For electrified solid-liquid interfaces, it has long been conventionally understood that only factors in the electrolyte phase are responsible for determining the reorganization energy and the electronic density of states (DOS) of the electrode serves only to dictate the number of thermally accessible channels for ET. Here we show instead that the electrode DOS plays a central role in governing the reorganization energy, far outweighing its conventionally assumed role. Using atomically layered heterostructures, we tune the DOS of graphene and measure outer-sphere ET kinetics. We find the ensuing variation in ET rate arises from strong modulation in a reorganization energy associated with image potential localization in the electrode. This work redefines the traditional paradigm of heterogeneous ET kinetics, revealing a deeper role of the electrode electronic structure in interfacial reactivity.

cond-mat.mtrl-sci↗

arXiv2024

Microscopic origin of twist-dependent electron transfer rate in bilayer graphene

Using molecular simulation and continuum dielectric theory, we consider how electrochemical kinetics are modulated by twist angle in bilayer graphene electrodes. By establishing a connection between twist angle and the screening length of charge carriers within the electrode, we investigate how tunable metallicity modifies the statistics of the electron transfer energy gap. Constant potential molecular simulations show that the activation free energy for electron transfer increases with screening length, leading to a non-monotonic dependence on the twist angle. The twist angle alters the density of states, tuning the number of thermally-accessible channels for electron transfer and the reorganization energy by affecting the stability of the vertically excited state through attenuated image charge interactions. Understanding these effects allows us to express the Marcus rate of interfacial electron transfer as a function of twist angle, consistent with a growing body of experimental observations.

cond-mat.stat-mech↗