How to Probe Hydrated Dielectrons Experimentally: Simulations of the Absorption Spectra of Aqueous Dielectrons, Electron Pairs, and Hydride.

In the radiation chemistry of water, two hydrated electrons () can react to form H and OH. Experiments and simulations suggest that this reaction occurs through a mechanism involving colocalization of two 's into the same solvent cavity, forming a hydrated dielectron intermediate, with aqueous hydride (H) as a subintermediate. However, there has been no direct experimental observation of either or H.

Simulating the Competitive Ion Pairing of Hydrated Electrons with Chaotropic Cations.

Experiments show that the absorption spectrum of the hydrated electron () blue-shifts in electrolyte solutions compared with what is seen in pure water. This shift has been assigned to the 's competitive ion-pairing interactions with the salt cation relative to the salt anion based on the ions' positions on the Hofmeister series. Remarkably, little work has been done investigating the 's behavior when the salts have chaotropic cations, which should greatly change the ion-pairing interactions given that the is a champion chaotrope.

Roles of H-Bonding and Hydride Solvation in the Reaction of Hydrated (Di)electrons with Water to Create H and OH.

Even though single hydrated electrons ('s) are stable in liquid water, two hydrated electrons can bimolecularly react with water to create H and hydroxide: + + 2HO → H + 2OH. The rate of this reaction has an unusual temperature and isotope dependence as well as no dependence on ionic strength, which suggests that cosolvation of two electrons as a single hydrated dielectron () might be an important intermediate in the mechanism of this reaction. Here, we present an ab initio density functional theory study of this reaction to better understand the potential properties, reactivity, and experimental accessibility of hydrated dielectrons.

How Solvation Alters the Thermodynamics of Asymmetric Bond-Breaking: Quantum Simulation of NaK in Liquid Tetrahydrofuran.

Gas-phase potential energy surfaces (PESs) are often used to provide an intuitive understanding of molecular chemical reactivity. Most chemical reactions, however, take place in solution, and it is unclear whether gas-phase PESs accurately represent chemical processes in solvent environments. In this work we use quantum simulations to investigate the dissociation energetics of NaK in liquid tetrahydrofuran (THF) to understand the degree to which solvent interactions alter the gas-phase picture.

Partial Molar Solvation Volume of the Hydrated Electron Simulated Via DFT.

Different simulation models of the hydrated electron produce different solvation structures, but it has been challenging to determine which simulated solvation structure, if any, is the most comparable to experiment. In a recent work, Neupane et al. [ , 127, 5941-5947] showed using Kirkwood-Buff theory that the partial molar volume of the hydrated electron, which is known experimentally, can be readily computed from an integral over the simulated electron-water radial distribution function.

Using Machine Learning to Understand the Causes of Quantum Decoherence in Solution-Phase Bond-Breaking Reactions.

Decoherence is a fundamental phenomenon that occurs when an entangled quantum state interacts with its environment, leading to collapse of the wave function. The inevitability of decoherence provides one of the most intrinsic limits of quantum computing. However, there has been little study of the precise chemical motions from the environment that cause decoherence.

Solvent Control of Chemical Identity Can Change Photodissociation into Photoisomerization.

In solution-phase chemistry, the solvent is often considered to be merely a medium that allows reacting solutes to encounter each other. In this work, however, we show that moderate locally specific solute-solvent interactions can affect not only the nature of the solute but also the types of reactive chemistry. We use quantum simulation methods to explore how solvent participation in solute chemical identity alters reactions involving the breaking of chemical bonds.