Effect of High-Frequency Modes and Hot Transitions on Free Energy Gap Dependence of Charge Recombination Rate

2006 ◽  
Vol 110 (43) ◽  
pp. 11919-11925 ◽  
Author(s):  
Serguei V. Feskov ◽  
Vladimir N. Ionkin ◽  
Anatoly I. Ivanov
Keyword(s):  
Free Energy ◽  
Recombination Rate ◽  
High Frequency ◽  
Energy Gap ◽  
Charge Recombination ◽  
High Frequency Modes

Free-Energy-Gap Law for Ultrafast Charge Recombination of Ion Pairs Formed by Intramolecular Photoinduced Electron Transfer

2017 ◽  
Vol 121 (3) ◽  
pp. 589-598 ◽  
Author(s):  
Alexey E. Nazarov ◽  
Roman Malykhin ◽  
Anatoly I. Ivanov
Keyword(s):  
Electron Transfer ◽  
Free Energy ◽  
Photoinduced Electron Transfer ◽  
Energy Gap ◽  
Ion Pairs ◽  
Charge Recombination ◽  
Energy Gap Law

Nonequilibrium Phenomena in Charge Recombination of Excited Donor−Acceptor Complexes and Free Energy Gap Law

2010 ◽  
Vol 114 (50) ◽  
pp. 12998-13004 ◽  
Author(s):  
Vladislav V. Yudanov ◽  
Valentina A. Mikhailova ◽  
Anatoly I. Ivanov
Keyword(s):  
Free Energy ◽  
Energy Gap ◽  
Charge Recombination ◽  
Nonequilibrium Phenomena ◽  
Energy Gap Law ◽  
Donor Acceptor

scholarly journals The effect of solvent relaxation time constants on free energy gap law for ultrafast charge recombination following photoinduced charge separation

2018 ◽  
Vol 17 (5) ◽  
pp. 607-616 ◽  
Author(s):  
Valentina A. Mikhailova ◽  
Roman E. Malykhin ◽  
Anatoly I. Ivanov
Keyword(s):  
Free Energy ◽  
Charge Separation ◽  
Energy Gap ◽  
Charge Recombination ◽  
Solvent Relaxation ◽  
Equilibrium Mode ◽  
Energy Gap Law ◽  
Photoinduced Charge Separation ◽  
Relaxation Time Constants ◽  
Photoinduced Charge

Ultrafast low exergonic charge recombination following photoinduced charge separation proceeds in a non-equilibrium mode and its rate constant is nearly independent of the free energy gap.

Diffusional distortion of the free‐energy gap law

1995 ◽  
Vol 103 (18) ◽  
pp. 7927-7933 ◽  
Author(s):  
A. I. Burshtein
Keyword(s):  
Free Energy ◽  
Energy Gap ◽  
Energy Gap Law

CHLORINE GAS SENSING OF SnO2 NANOCLUSTERS AS A FUNCTION OF TEMPERATURE: A DFT STUDY

2019 ◽  
Vol 26 (04) ◽  
pp. 1850172
Author(s):  
MUDAR AHMED ABDULSATTAR ◽  
ADEEBH L. RESNE ◽  
SHROK ABDULLAH ◽  
RIYADH J. MOHAMMED ◽  
NOON KADHUM ALARED ◽  
...  
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Tin Dioxide ◽  
Energy Gap ◽  
Gas Sensing ◽  
Free Energy Calculations ◽  
Measured Temperature ◽  
Chlorine Molecule ◽  
Chlorine Gas

Density functional theory combined with Gibbs free energy calculations is used to study the sensing behavior of tin dioxide (SnO[Formula: see text] clusters towards chlorine gas molecules. Studied SnO2 clusters’ results show the known property of tin dioxide being an oxygen-deficient semiconductor with the preferred stoichiometry SnO[Formula: see text]. The kind of reactions that result in sensing Cl2 molecules is investigated. These include oxygen replacement, chlorine molecule dissociation and van der Waals attachment. Oxygen replacement shows an increase in energy gap which is the case experimentally. Optimum sensing operating temperature towards Cl2 molecules that results from the intersection of the highest SnO2 adsorption and desorption Gibbs free energy lines is at 275∘C in agreement with the experimentally measured temperature of 260∘C.

Shock Mitigation by Energy Reversal to the High Frequency Modes

2014 ◽  
Author(s):  
Mohammad A. AL-Shudeifat ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Computational Study ◽  
Dynamic Structure ◽  
Frequency Mode ◽  
Frame Structure ◽  
Shock Energy ◽  
Modal Damping ◽  
Shock Mitigation ◽  
High Frequency Modes

In this computational study, a light-weight dynamic device is investigated for passive energy reversal from the lowest frequency mode to the high frequency modes of a large-scale frame structure for rapid shock mitigation. The device is based on the single-sided vibro-impact mechanism. It has two functions for passive energy transfer: a nonlinear energy sink (NES) for local energy dissipation and an energy pump to high frequency modes where a significant amount of the shock energy is rapidly dissipated. As a result, a significant portion of the shock energy induced into the linear dynamic structure can be passively reversed from the lowest frequency mode to the high frequency modes and rapidly dissipated by their modal damping. The amount of the energy dissipated by the modal damping of the high frequency modes can be controlled by the amount of inherent damping in the device. Ideally, the device can passively reverse up to 80% of the input shock energy from the lowest frequency mode to the high frequency modes when its damping is assumed to be zero and its impact coefficient of restitution is equal to unity. The shock energy redistribution between this device and the high frequency modes is found to be efficient for rapid shock mitigation in the considered 9-story dynamic structure.

scholarly journals Competitive cocrystallization and its application in the separation of flavonoids

IUCrJ ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 195-207
Author(s):  
Yanming Xia ◽  
Yuanfeng Wei ◽  
Hui Chen ◽  
Shuai Qian ◽  
Jianjun Zhang ◽  
...  
Keyword(s):  
Free Energy ◽  
Formation Constant ◽  
Energy Gap ◽  
Hirshfeld Surface ◽  
Methanol Solution ◽  
Model Compounds ◽  
Electronic Density ◽  
Chemical Structures ◽  
Similar Chemical ◽  
Interaction Contribution

Recently, cocrystallization has been widely employed to tailor physicochemical properties of drugs in the pharmaceutical field. In this study, cocrystallization was applied to separate natural compounds with similar structures. Three flavonoids [baicalein (BAI), quercetin (QUE) and myricetin (MYR)] were used as model compounds. The coformer caffeine (CAF) could form cocrystals with all three flavonoids, namely BAI–CAF (cocrystal 1), QUE–CAF (cocrystal 2) and MYR–CAF (cocrystal 3). After adding CAF to methanol solution containing MYR and QUE (or QUE and BAI), cocrystal 3 (or cocrystal 2) preferentially formed rather than cocrystal 2 (or cocrystal 1), indicating that flavonoid separation could be achieved by competitive cocrystallization. After co-mixing the slurry of two flavonoids with CAF followed by centrifugation, the resolution ratio that could be achieved was 70–80% with purity >90%. Among the three cocrystals, cocrystal 3 showed the lowest formation constant with a negative Gibbs free energy of nucleation and the highest energy gap. Hirshfeld surface analysis and density of states analysis found that cocrystal 3 had the highest strong interaction contribution and the closest electronic density, respectively, followed by cocrystal 2 and cocrystal 1, suggesting CAF could competitively form a cocrystal with MYR much more easily than QUE and BAI. Cocrystallization is a promising approach for green and effective separation of natural products with similar chemical structures.

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