scholarly journals Cavity frequency-dependent theory for vibrational polariton chemistry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xinyang Li ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Molecular System ◽  
Reaction Rate Constant ◽  
Theoretical Explanation ◽  
State Theory ◽  
Rate Theory ◽  
Radiation Mode ◽  
Frequency Dependent ◽  
Markovian Dynamics ◽  
Photon Frequency ◽  
Dependent Modification

AbstractRecent experiments demonstrate the control of chemical reactivities by coupling molecules inside an optical microcavity. In contrast, transition state theory predicts no change of the reaction barrier height during this process. Here, we present a theoretical explanation of the cavity modification of the ground state reactivity in the vibrational strong coupling (VSC) regime in polariton chemistry. Our theoretical results suggest that the VSC kinetics modification is originated from the non-Markovian dynamics of the cavity radiation mode that couples to the molecule, leading to the dynamical caging effect of the reaction coordinate and the suppression of reaction rate constant for a specific range of photon frequency close to the barrier frequency. We use a simple analytical non-Markovian rate theory to describe a single molecular system coupled to a cavity mode. We demonstrate the accuracy of the rate theory by performing direct numerical calculations of the transmission coefficients with the same model of the molecule-cavity hybrid system. Our simulations and analytical theory provide a plausible explanation of the photon frequency dependent modification of the chemical reactivities in the VSC polariton chemistry.

scholarly journals Resonance Theory of Vibrational Strong Couplings in Polariton Chemistry

2020 ◽  
Author(s):  
Xinyang Li ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Chemical Reaction ◽  
Molecular System ◽  
Optical Cavity ◽  
Theoretical Explanation ◽  
Rate Theory ◽  
Resonance Theory ◽  
Radiation Mode ◽  
Cavity Radiation ◽  
Photon Frequency ◽  
Kinetics Of

<div>In this work, we present a new theoretical explanation of the resonance vibrational strong coupling (VSC) regime in polariton chemistry. Coupling molecular vibrations and the cavity photonic excitation has experimentally demonstrated to strongly influence the ground state kinetics of a chemical reaction. Our theoretical results suggest that the VSC kinetics modification originates from the non-Markovian behavior of the cavity radiation mode when coupling to the molecule, leading to the dynamical caging of the reaction coordinate and the suppression of chemical reaction rate for a given range of photon frequency that is close to the barrier frequency. Further, we use a simple analytical non-Markovian rate theory to describe a single molecular system coupled to a radiation mode in an optical cavity. We demonstrate the accuracy of the rate theory by performing a numerical calculation in a one-dimensional model molecular system coupled to the cavity. Our simulations and analytical theory demonstrate the importance of dynamical effects in VSC polaritonic chemistry.</div>

scholarly journals Resonance Theory of Vibrational Strong Couplings in Polariton Chemistry

2020 ◽  
Author(s):  
Xinyang Li ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Chemical Reaction ◽  
Molecular System ◽  
Optical Cavity ◽  
Theoretical Explanation ◽  
Rate Theory ◽  
Resonance Theory ◽  
Radiation Mode ◽  
Cavity Radiation ◽  
Photon Frequency ◽  
Kinetics Of

<div>In this work, we present a new theoretical explanation of the resonance vibrational strong coupling (VSC) regime in polariton chemistry. Coupling molecular vibrations and the cavity photonic excitation has experimentally demonstrated to strongly influence the ground state kinetics of a chemical reaction. Our theoretical results suggest that the VSC kinetics modification originates from the non-Markovian behavior of the cavity radiation mode when coupling to the molecule, leading to the dynamical caging of the reaction coordinate and the suppression of chemical reaction rate for a given range of photon frequency that is close to the barrier frequency. Further, we use a simple analytical non-Markovian rate theory to describe a single molecular system coupled to a radiation mode in an optical cavity. We demonstrate the accuracy of the rate theory by performing a numerical calculation in a one-dimensional model molecular system coupled to the cavity. Our simulations and analytical theory demonstrate the importance of dynamical effects in VSC polaritonic chemistry.</div>

scholarly journals “Transitivity”: A Code for Computing Kinetic and Related Parameters in Chemical Transformations and Transport Phenomena

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3478 ◽  
Author(s):  
Hugo G. Machado ◽  
Flávio O. Sanches-Neto ◽  
Nayara D. Coutinho ◽  
Kleber C. Mundim ◽  
Federico Palazzetti ◽  
...  
Keyword(s):  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
State Theory ◽  
Chemical Transformations ◽  
Graphical Interface ◽  
Arrhenius Behavior ◽  
Reaction Rate Constants ◽  
Kinetic And Thermodynamic Parameters ◽  
Data Documentation

The Transitivity function, defined in terms of the reciprocal of the apparent activation energy, measures the propensity for a reaction to proceed and can provide a tool for implementing phenomenological kinetic models. Applications to systems which deviate from the Arrhenius law at low temperature encouraged the development of a user-friendly graphical interface for estimating the kinetic and thermodynamic parameters of physical and chemical processes. Here, we document the Transitivity code, written in Python, a free open-source code compatible with Windows, Linux and macOS platforms. Procedures are made available to evaluate the phenomenology of the temperature dependence of rate constants for processes from the Arrhenius and Transitivity plots. Reaction rate constants can be calculated by the traditional Transition-State Theory using a set of one-dimensional tunneling corrections (Bell (1935), Bell (1958), Skodje and Truhlar and, in particular, the deformed ( d -TST) approach). To account for the solvent effect on reaction rate constant, implementation is given of the Kramers and of Collins–Kimball formulations. An input file generator is provided to run various molecular dynamics approaches in CPMD code. Examples are worked out and made available for testing. The novelty of this code is its general scope and particular exploit of d -formulations to cope with non-Arrhenius behavior at low temperatures, a topic which is the focus of recent intense investigations. We expect that this code serves as a quick and practical tool for data documentation from electronic structure calculations: It presents a very intuitive graphical interface which we believe to provide an excellent working tool for researchers and as courseware to teach statistical thermodynamics, thermochemistry, kinetics, and related areas.

scholarly journals Viscosity model of deep eutectic solvents from group contribution method

2022 ◽  
Author(s):  
Liuying Yu ◽  
Xiaojing Hou ◽  
Gao-Peng Ren ◽  
Kejun Wu ◽  
Chao-Hong He
Keyword(s):  
Deep Eutectic Solvents ◽  
State Theory ◽  
Group Contribution ◽  
Rate Theory ◽  
Model Parameters ◽  
Training Set ◽  
Free Volume Theory ◽  
Relative Deviation ◽  
Proposed Model ◽  
Very High

In this work, based on mathematical model inspired by transition state theory, the group contribution (GC) method is used to predict the viscosity of DESs. The model is constrained by Eyring rate theory and hard sphere free volume theory. A dataset of 2229 experimental measurements of the viscosity of 183 DESs from literature is used for determining the model parameters and subsequent verification of the model. The rules introduced by this model are simple and easy to understand. The results show that the proposed model is able to predict the DESs viscosity with very high accuracy, i.e., with an average absolute relative deviation of 8.12% over the training set and 8.64% over the test set, using only temperature and composition as inputs. The maximum absolute relative deviation is 34.63%. Therefore, the as-proposed model can be considered a highly reliable tool for predicting DESs viscosity when experimental data are absent.

scholarly journals Adiabatic versus Non-Adiabatic Electron Transfer at 2D Electrode Materials

2021 ◽  
Author(s):  
Dan-Qing Liu ◽  
Minkyung Kang ◽  
David Perry ◽  
Chang-Hui Chen ◽  
Geoff West ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Electrode Materials ◽  
Copper Substrate ◽  
State Theory ◽  
Experimental Methodology ◽  
Diffusion Limit ◽  
Rate Theory ◽  
Multilayer Graphene ◽  
Contact Potential

<div><div><div><p>Outer-sphere electron transfer (OS-ET) is a cornerstone elementary electrochemical reaction, yet microscopic understanding is largely based on idealized theories, developed in isolation from experiments that themselves are often close to the kinetic (diffusion) limit. Focusing on graphene as-grown on a copper substrate as a model 2D material/metal-supported electrode system, this study resolves the key electronic interactions in OS-ET, and identifies the role of graphene in modulating the electronic properties of the electrode/electrolyte interface. An integrated experimental-theoretical approach combining co-located multi-microscopy, centered on scanning electrochemical cell microscopy (SECCM), with Raman microscopy and field emission-scanning electron microscopy, together with rate theory and density functional theory calculations is used to address OS-ET kinetics of hexaamineruthenium (III/II) chloride, [Ru(NH3)6]3+/2+. The experimental methodology allows spatially-resolved electrochemical measurements to be targeted at distinct regions of monolayer, bilayer and multilayer graphene on copper, with high diffusion rates, to reveal ET kinetics in the order: monolayer > bilayer > multilayer. Theoretical and computational methods combining the Schmickler-Newns-Anderson model, transition state theory, and constant potential DFT reveal that the difference in kinetics at monolayer and bilayer graphene can be rationalized in the context of a dominantly adiabatic mechanism, where the addition of subsequent graphene layers increases the contact potential, producing an increase in the effective barrier to electron transfer. This study provides a roadmap for the integration of experiments and theory in order to understand the nature of heterogeneous electron transfer at complex nanostructured electrode materials.</p></div></div></div>

scholarly journals Reaction rate theory: summarising remarks

2016 ◽  
Vol 195 ◽  
pp. 699-710 ◽  
Author(s):  
David Chandler ◽  
David E. Manolopoulos
Keyword(s):  
Transition State ◽  
Transition State Theory ◽  
Reaction Rate ◽  
Rare Event ◽  
State Theory ◽  
Rate Theory ◽  
Reaction Rate Theory ◽  
Adiabatic Dynamics

This paper summarizes the contributions to the Faraday Discussion on reaction rate theory. The topics range from contemporary usage of transition state theory, including rare event sampling, to instantons and non-adiabatic dynamics.

scholarly journals Mode-Selective Chemistry through Polaritonic Vibrational Strong Coupling

2021 ◽  
Author(s):  
Xinyang Li ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Quantum Electrodynamics ◽  
Optical Cavity ◽  
Cavity Quantum Electrodynamics ◽  
Reaction Coordinate ◽  
Vacuum Fluctuations ◽  
Radiation Mode ◽  
Competitive Reactions ◽  
Photon Frequency ◽  
Theoretical Results ◽  
Fundamental Mechanism

Recent experiments have demonstrated remarkable mode-selective reactivities by coupling molecular vibrations with vacuum fluctuations inside an optical cavity. The fundamental mechanism behind such effects, on the other hand, remains elusive. In this work, we theoretically demonstrate the basic principle of how cavity photon frequency can be tuned to achieve mode-selective reactivities. We find that the non-Markovian nature of the radiation mode leads to a cavity frequency-dependent dynamical caging effect of a reaction coordinate, resulting in a suppression of the rate constant. In the presence of multiple competitive reactions, it is possible to preferentially cage a reaction coordinate when the barrier frequencies for competing reaction paths are different. Our theoretical results illustrate the cavity-induced mode-selective chemistry through polaritonic vibrational-strong couplings, revealing the fundamental mechanism for changing chemical selectivities through cavity quantum electrodynamics.

Reaction Rate Constant of CH2O + H = HCO + H2 Revisited: A Combined Study of Direct Shock Tube Measurement and Transition State Theory Calculation

2014 ◽  
Vol 118 (44) ◽  
pp. 10201-10209 ◽  
Author(s):  
Shengkai Wang ◽  
Enoch E. Dames ◽  
David F. Davidson ◽  
Ronald K. Hanson
Keyword(s):  
Transition State ◽  
Shock Tube ◽  
Rate Constant ◽  
Transition State Theory ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
State Theory ◽  
Theory Calculation
Sign in / Sign up

Export Citation Format

Share Document