I. A. Shkrob
A review with 106 references of the recent advances in understanding the structure, dynamics, and photodynamics of solvated electrons in polar liquids (and, to some degree, clusters): water, alcohols, ammonia, ethers. Both the orthodox (cavity) and heterodox (multimer anion) pictures of the solvated electron are discussed.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Nonlinear terahertz polarizability of electrons solvated in a polar liquid
本研究利用二维太赫兹光谱探究液态2-丙醇中溶剂化电子的非线性极化子响应，观测到非共振脉冲对极化子振荡相位的调控，且该非线性极化率变化得到理论计算验证。
The terahertz (THz) response of solvated electrons in liquid water is studied in nonlinear ultrafast pump-probe experiments. Free electrons with concentrations from c_e = 4 to 140 \times 10-6 moles/liter are generated by high-field THz or near-infrared multiphoton excitation. The time-resolved change of the dielectric function as mapped by broadband THz pulses exhibits pronounced oscillations persisting up to 30 ps. Their frequency increases with electron concentration from 0.2 to 1.5 THz. The oscillatory response is assigned to impulsively excited coherent polarons involving coupled electron …
Below band gap formation of solvated electrons in neutral water clusters using pump-probe photoelectron imaging is compared with recent data for liquid water and with above band gap excitation studies in the liquid and clusters. Similar relaxation times in the order of 200 fs and 1-2 ps are retrieved for below and above band gap excitation, in both clusters and liquid. The relaxation times independence from the generation process indicates that these times are dominated by the solvent response, which is significantly slower than the different solvated electron formation processes. The analysis…
The benzene radical anion is a molecular ion pertinent to several organic reactions, including the Birch reduction of benzene in liquid ammonia. The species exhibits a dynamic Jahn-Teller effect due to its open-shell nature and undergoes pseudorotation of its geometry. Here we characterize the complex electronic structure of this condensed-phase system based on ab initio molecular dynamics simulations and GW calculations of the benzene radical anion solvated in liquid ammonia. Using detailed analysis of molecular and electronic structure, we find that the spatial character of the excess electr…
Solvated electrons in polar liquids as epsilon-near-zero materials tunable in the terahertz frequency range
本研究探讨了极性液体中电子的极化子共振对太赫兹光传播的影响，通过实验和局域场方法计算证实其表现出可调的epsilon-near-zero材料特征行为。
The solvated electron represents an elementary quantum system in a liquid environment. Electrons solvated in water have raised strong interest because of their prototypical properties, their role in radiation chemistry, and their relevance for charge separation and transport. Nonequilibrium dynamics of photogenerated electrons in water occur on ultrafast time scales and include charge transfer, localization, and energy dissipation processes. We present new insight in the role of fluctuating electric fields of the liquid for generating electrons in presence of an external terahertz field and ad…
Recent atomic force microscopy (AFM) can measure force curves between a probe and a sample surface in several solvents. The force curve is thought as the solvation structure in some cases, because its shape is generally oscilltive and pitch of the oscillation is about the same as diameter of the solvent. However, it is not the solvation structure. It is just only a mean force between the probe and sample surface. Since theoretical relation between the mean force and the solvation structure had not been clearly known, we have recently derived a relational expression within a simple liquid. Alth…
In this work, we extend the quantum optimal control theory of molecules subject to ultrashort laser pulses to the case of solvated systems, explicitly including the solvent dielectric properties in the system Hamiltonian. A reliable description of the solvent polarization is accounted for within the Polarizable Continuum Model (PCM). The electronic dynamics for the molecule in solution is coupled with the dynamics of the surrounding polarizable environment, that affects the features of the optimized light pulse. Examples on test molecules are presented and discussed to illustrate such effects.
Two recent articles present results that allegedly exclude a possible multimodal distribution of the hydrated electron in ultraviolet photoelectron spectra. The first article bases its conclusion on the assumption that the non-Gaussian genuine band shape previously retrieved for the solvated electron in liquid water is an artefact arising from insufficient electron scattering cross sections used in the retrieval. The second article excludes a multimodal band shape based on a photoelectron spectrum of the solvated electron in water clusters recorded at a single ultraviolet photon energy, and it…
While ionization of some polyatomic molecular liquids (such as water and aliphatic alcohols) yields so-called "solvated electrons" in which the excess electron density is localized in the interstices between the solvent molecules, most organic and inorganic liquids yield radical anions and cations in which the electron and spin densities reside on the solvent molecule or, more commonly, a group of such molecules. The resulting multimer ions have many unusual properties, such as high rates of diffusive hopping. The "solvated electron" can be regarded as a variant of a multimer radical anion in …
Recent atomic force microscopy (AFM) can measure force curves between a probe and a sample surface in solvent. The force curve is thought as the solvation structure in some cases, because its shape is generally oscilltive and pitch of the oscillation is about the same as diameter of the solvent. However, it is not the solvation structure. It is just only a mean force between the probe and the sample surface. A theoretical relation between the mean force and the solvation structure is not clearly known. Therefore, the relation must be elucidated theoretically to deepen understanding of the mean…
We have investigated the solvation dynamics and the genuine binding energy and photoemission anisotropy of the solvated electron in neutral water clusters with a combination of time-resolved photoelectron velocity map imaging and electron scattering simulations. The dynamics was probed with a UV probe pulse following above-band-gap excitation with a EUV pump pulse. The solvation dynamics is completed within about 2 ps. Only a single band is observed in the spectra, with no indication for isomers with distinct binding energies. Data analysis with an electron scattering model reveals a genuine b…
A subsystem approach for obtaining electron binding energies in the valence region and apply it to the case of halide ions (X$^-$, X = F-At) in water. This approach is based on electronic structure calculations combining the relativistic equation of motion coupled-cluster method for electron detachment (EOM-IP-CCSD) and density functional theory via the frozen density embedding (FDE) approach, using structures from classical molecular dynamics with polarizable force fields for discrete systems (in the present study, droplets containing the anion and 50 water molecules). Our results indicate on…
Due to solvation, excess charge carriers on 1d semiconductor nanostructures immersed in polar solvents undergo self-localization into polaronic states. Using a simplified theoretical model for small-diameter structures, we study low-frequency properties of resulting 1d adiabatic polarons. The combined microscopic dynamics of the electronic charge density and the solvent leads to macroscopic Langevin dynamics of a polaron and to the appearance of local dielectric relaxation modes. Polaron mobility is evaluated as a function of system parameters. Numerical estimates indicate that the solvated ca…
Birch reduction is a time-proven way to hydrogenate aromatic hydrocarbons (such as benzene), which relies on the reducing power of electrons released from alkali metals into liquid ammonia. We have succeeded to characterize the key intermediates of the Birch reduction process - the solvated electron and dielectron and the benzene radical anion - using cyclic voltammetry and photoelectron spectroscopy, aided by electronic structure calculations. In this way, we not only quantify the electron binding energies of these species, which are decisive for the mechanism of the reaction but also use Bir…
Recently, it became practicable to study geminate recombination dynamics of solvated electrons in polar liquids by using short pulses of light to reexcite these electrons back into the conduction band of the liquid and observe a change in the fraction of electrons that escape geminate recombination. In this Letter, the potential of this technique to provide additional insight into the recombination dynamics of electrons generated by charge-transfer-to-solvent (CTTS) photodetachment from monovalent anions in polar liquids is studied theoretically. The resulting expression accounts for the recen…
Using molecular dynamics simulations, the structure of model mini-protein was thoroughly characterized in the imidazolium-based amino acid ionic liquids and their aqueous solutions. We report that the mini-protein is more stable when AAIL is added as a cosolvent. Complete substitution of water by organic cations and anions further results in hindered conformational flexibility of the mini-protein. This observation suggests that AAILs are able to defend proteins from thermally induced denaturation. We show by means of radial distributions that the mini-protein is efficiently solvated by both so…
A Simple Molecular Model for Hydrated Silicate Ionic Liquids, a Realistic Zeolite Precursor
本研究开发了水合硅酸盐离子液体（HSILs）的简单分子模型，结合分子动力学模拟与实验，揭示了碱金属阳离子对HSIL结构的调控作用及硅酸盐单体缩合机制，为理解分子筛早期成核过程迈出重要一步。
Steric hindered frustrated Lewis pairs (FLPs) have been shown to activate hydrogen molecules, and their reactivity is strongly determined by the geometric parameters of the Lewis acid s and bases. A recent experimental study showed that ionic liquids (ILs) could largely improve the effective configuration of FLPs. However, the detailed mechanistic profile is still unclear. Herein, we performed a molecular dynamics (MD) simulations, aimi ng to reveal the effects of ILs on the structures of FLPs, and to present a rule for selecting more efficient reaction media. For this purpose, mixture systems…
We propose an enhanced approach to the extrapolation of mean potential forces acting on atoms of solute macromolecules due to their interactions with solvent atoms in complex biochemical liquids. It improves and extends previous extrapolation schemes by including additionally new techniques such as an exponential scaling transformation of coordinate space with weights complemented by a dynamically adjusted balancing between the least square minimization of force deviations and the norm of expansion coefficients in the approximation. The expensive mean potential forces are treated in terms of t…
We applied angular X-ray Cross-Correlation analysis (XCCA) to scattering images from a femtosecond resolution LCLS X-ray free-electron laser (XFEL) pump-probe experiment with solvated PtPOP ([Pt$_2$(P$_2$O$_5$H$_2$)$_4$]$^{4-}$) metal complex molecules. The molecules were pumped with linear polarized laser pulses creating an excited state population with a preferred orientational (alignment) direction. Two time scales of $1.9\pm1.5$ ps and $46\pm10$ ps were revealed by model-independent XCCA, associated with an internal structural changes and rotational dephasing, respectively. Our studies ill…
Zeta potentials of several polar protic (water, ethylene glycol, formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three non-polar surfaces using closed-cell electro-osmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited substantial electrokinetics in contact with the non-polar surfaces with these observations: the electrokinetic effect on the fluorocarbon-coated surface is the strongest; and on a PDMS grafted surface, the …
We demonstrate the applicability of extended Lagrangian Born-Oppenheimer quantum-based molecular dynamics (XL-BOMD) to model electron transfer reactions occurring on solid-liquid interfaces. Specifically, we consider the reduction of O$_2$ as catalyzed at the interface of an N-doped graphene sheet and H$_2$O at fuel cell cathodes. This system is a good testbed for next-generation computational chemistry methods since the electrochemical functionalities strongly depend on atomic-scale quantum mechanics. As opposed to prior iterations of first principles molecular dynamics, XL-BOMD only requires…
Ionization of polar liquids and glasses often yields metastable electron centers collectively known as weakly bound (wb) electrons that absorb to the red of the ground state of the solvated/trapped electron. Formation of these species is thought to be the initial stage of electron localization in such media. Although these commonly occurring species have distinctive absorption spectra, no insight into their structure currently exists. In this Letter, we address the structure of the wb electron in low-temperature ice-Ih theoretically, using a combination of mixed quantum-classical (MQC) floatin…
Thermodynamics of Mixtures Containing a Strongly Polar Compound. 9. Liquid-Liquid Equilibria for $ε$-CAPROLACTAM + Selected Alkanes
本研究通过激光散射临界乳光法测定ε-己内酰胺与多种烷烃的液-液平衡共存曲线，发现UCST随正构烷烃链长线性增加，且辛烷体系的UCST低于2,2,4-三甲基戊烷体系。
Post-collision interaction in the liquid phase: the role of electron scattering
本文研究液相中溶剂化Cl⁻、K⁺和Ca²⁺的Auger KLL电子碰撞后相互作用，发现三种等电子离子行为相似且受溶剂影响小，提出用电子输运蒙特卡洛模拟替代修正半经典理论可更好地解释实验，并建议将PCI数据用于约束低能电子在水中的散射参数。
Continuum solvent models have become a standard technique in the context of electronic structure calculations, yet, no implementations have been reported capable to perform molecular dynamics at solid-liquid interfaces. We propose here such a continuum approach in a DFT framework, using plane-waves basis sets and periodic boundary conditions. Our work stems from a recent model designed for Car-Parrinello simulations of quantum solutes in a dielectric medium [J. Chem. Phys. 124, 74103 (2006)], for which the permittivity of the solvent is defined as a function of the electronic density of the so…
The Photochemical Birth of the Hydrated Electron in Liquid Water
研究通过分子动力学模拟揭示了液态水在紫外光照射下生成水合电子的关键化学过程，揭示了两种主要反应路径及超快运动对离子-自由基对形成的影响。
We present the results of numerical simulations of fluctuations of the electrostatic potential and electric field inside cavities created in the fluid of dipolar hard spheres. We found that the thermodynamics of polar solvation dramatically changes its regime when the cavity size becomes about 4-5 times larger than the size of the liquid particle. The range of small cavities can be reasonably understood within the framework of current solvation models. On the contrary, the regime of large cavities is characterized by a significant softening of the cavity interface resulting in a decay of the f…
An electronically coarse-grained model for water reveals a persistent vestige of the liquid-gas transition deep into the supercritical region. A crossover in the density dependence of the molecular dipole arises from the onset of non-percolating hydrogen bonds. The crossover points coincide with the Widom line in the scaling region but extend further, tracking the heat capacity maxima, offering evidence for liquid- and gas-like state points in a "one-phase" fluid. The effect is present even in dipole-limit models suggesting that it is common for all molecular liquids exhibiting dipole enhancem…
Modeling Reactions on the Solid-Liquid Interface With Next Generation Extended Lagrangian Quantum-Based Molecular Dynamics
该研究采用XL-BOMD框架模拟ORR，发现偏压会改变反应机制，其动力学与常用理论有差异，为电催化过程提供了预测性原子级洞察。
We develop a phenomenological vector model of polar liquids capable to describe aqueous interactions of macroscopic bodies. It is shown that a strong, long-range and orientationally dependent interaction between macroscopic objects appears as a result of competition between short-range (hydrogen bonding) and the long-range dipole-dipole interactions of the solvent molecules. Spontaneous polarization of molecular dipoles next to a hydrophobic boundaries leads to formation of globally ordered network of hydrogen-bonded molecules with ferroelectric properties. The proposed vector model naturally …
We demonstrate three-dimensional vibrational imaging of director structures in liquid crystals using coherent anti-Stokes Raman scattering (CARS) polarized microscopy. Spatial mapping of the structures is based on sensitivity of a polarized CARS signal to orientation of anisotropic molecules in liquid crystals. As an example, we study structures in a smectic material and demonstrate that single-scan CARS and two-photon fluorescence images of molecular orientation patterns are consistent with each other and with the structure model.
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。