In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction w...In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction with the complex rotation of the Hamiltonian,were used to determine their wave functions.The electron densities,Fukui functions,and values of the hyper-radius<r^2>were computed from these wave functions.The Fukui functions have negative regions in the valence shell in addition to the inner shell regions,indicating screening effects of the outer temporary electron.Selected configuration interactions with up to quadruple excitations were used along the trajectories and for computing the final wave function.Based on this data,the densities,Fukui functions,and<r^2>were calculated.展开更多
Strategic fluorination of solvent,a prominent strategy to enhance the electrolyte oxidation resistance and engineer a robust cathode-electrolyte interface,is crucial for realizing high-voltage lithium-ion batteries.Ac...Strategic fluorination of solvent,a prominent strategy to enhance the electrolyte oxidation resistance and engineer a robust cathode-electrolyte interface,is crucial for realizing high-voltage lithium-ion batteries.Actually,the adaptability of fluorinated solvents to high voltages is critically determined by the degree of fluorination and the fluorination site,yet lacks systematic design principles.Herein,we introduce a solvent screening descriptor based on ionization energy and Fukui function to assess molecular and site-specific reactivity.Computational and experimental results demonstrate that an optimal solvent with low ground-state energies and reactive sites is required as an ideal candidate for high-voltage electrolytes.Among derivatives from anisole,(trifluoromethoxy)benzene is identified as a superior candidate,enabling the formulation of a low reactivity solution(LPT)as electrolyte.Remarkably,the prepared Li‖LCO cell using LPT electrolyte maintained a high-capacity retention of 78.8%after 600 cycles at 4.5 V.In addition,the formation of an inorganic-rich interphase from LPT electrolyte effectively suppresses structural degradation to ensure a fast dynamic behavior.The utilization of LPT electrolyte also greatly reduces the amount of heat released and the production of O_(2)gas,which is favorable for addressing thermal runaway hazards.This screening strategy offers a practical approach for the design of flame-retardant high-voltage electrolytes.展开更多
Based on the density functional theory,we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons.De...Based on the density functional theory,we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons.Descriptors including global softness,Fukui function,local softness and local mulliken charge were calculated at SVWN/DN~* level of DFT with PC Spartan Pro.Nucleophilicity and basicity of 28 selected compounds were classified based on intensity.BP algorithm of artificial neural network(ANN) was employed to study the relationship between the descriptors and nucleophilicity/basicity.Cross-validation was carried out to avoid the over-fitting in training of ANN.A BP network was trained to quantify the relationship between HSAB-theory-based properties and nucleophilicity/basicity of compounds with lone-pair electrons.The results show that the prediction based on the network matches with the experimental results well.The local softness and Fukui function have a better relationship with nucleophilicity and local mulliken charge than with the basicity.The trained BP network could be utilized for predicting the nucleophilicity/basicity of compounds or functional groups with lone-pair electrons.展开更多
Based on the density functional theory, we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons. ...Based on the density functional theory, we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons. Descriptors including global softness, Fukui function, local softness and local mulliken charge were calculated at SVWN/DN＊ level of DFT with PC Spartan Pro. Nucleophilicity and basicity of 28 selected compounds were classified based on intensity. BP algorithm of artificial neural network （ANN） was employed to study the relationship between the descriptors and nucleophilicity/basicity. Cross-validation was carried out to avoid the over-fitting in training of ANN. A BP network was trained to quantify the relationship between HSAB-theory-based properties and nucleophilicity/basicity of compounds with lone-pair electrons. The results show that the prediction based on the network matches with the experimental results well. The local softness and Fukui function have a better relationship with nucleophilicity and local mulliken charge than with the basicity. The trained BP network could be utilized for predicting the nucleophilicity/basicity of compounds or functional groups with lone-pair electrons.展开更多
Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-...Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate states.Spatialpseudo-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended systems.Given the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited states.Here we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of states.The local softness is approximately equal to the density of states at the Fermi level.However,such approximation leaves out the contribution of inner states.In order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is presented.Single wall capped carbon nanotubes(SWCCNT)illustrate the limitation of the frontier orbital theory in extended systems.Thus,we have used a C360 SWCCNT to test the proposed model and how it compares with available models based on the local density of states.Interestingly,a simple Hückel approximation captures the main features of chemical response of these systems.Our results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.展开更多
Triacetone triperoxide （TATP） is more sensitive than diacetone diperoxide （DADP） in the solid-state explosion. To explain this reactivity difference, we analyzed the electronic structures and properties of the cry...Triacetone triperoxide （TATP） is more sensitive than diacetone diperoxide （DADP） in the solid-state explosion. To explain this reactivity difference, we analyzed the electronic structures and properties of the crystals of both compounds by using Ab initio method to calculate the structures of their individual molecules as well as their lattice structures and particularly calculating Nuclear Fukui function to gain insight into the sensitivity of the initial, rate-determining step of their decomposition. Our results indicate that TATP and DADP crystal structures exhibit significantly different electronic proper- ties. Most notably, the electronic structure of the TATP crystal shows asymmetry among its reactive oxygen atoms as supported by magnitudes of their nuclear Fukui functions. The greater explosion sensitivity of crystalline TATP may be attributed to the properties of its electronic structure. The electronic calculations provided valuable insight into the decomposition sensitivity difference between TATP and DADP crystals.展开更多
Atrazine(ATZ),as one of the most extensively employed organochlorine-based herbicides,exhibits persistence and environmental toxicity.Photocatalytic technology based on polymer carbon nitride is regarded as a sus-tain...Atrazine(ATZ),as one of the most extensively employed organochlorine-based herbicides,exhibits persistence and environmental toxicity.Photocatalytic technology based on polymer carbon nitride is regarded as a sus-tainable and promising approach for the degradation of emerging organic pollutants.Regrettably,the inherent shortcomings of pure carbon nitride greatly limit its practical application.Herein,S-doped carbon nitride was elaborately constructed for efficient degradation of ATZ.The removal efficiency of ATZ by the optimal sample(0.052 min^(-1))is 3.25 times as that of pure carbon nitride(0.016 min^(-1)).Experiments and DFT calculations show that S doping optimizes electronic structure of carbon nitride,which significantly enhances the spatial separation and transfer efficiency of photogenerated electrons and holes.Moreover,the reactive sites and degradation paths of ATZ were predicted by Fukui function and LC-MS determination.Our work provides an effective approach for the design of efficient photocatalysts to achieve efficient environmental remediation.展开更多
文摘In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction with the complex rotation of the Hamiltonian,were used to determine their wave functions.The electron densities,Fukui functions,and values of the hyper-radius<r^2>were computed from these wave functions.The Fukui functions have negative regions in the valence shell in addition to the inner shell regions,indicating screening effects of the outer temporary electron.Selected configuration interactions with up to quadruple excitations were used along the trajectories and for computing the final wave function.Based on this data,the densities,Fukui functions,and<r^2>were calculated.
基金financial support from the National Natural Science Foundation of China(22522814,22278378,and 52402318)Zhejiang Provincial Natural Science Foundation of China(LDQ24E030001 and LQN25E020003)Science Foundation of Zhejiang Sci-Tech University(22212011-Y and 24212149-Y).
文摘Strategic fluorination of solvent,a prominent strategy to enhance the electrolyte oxidation resistance and engineer a robust cathode-electrolyte interface,is crucial for realizing high-voltage lithium-ion batteries.Actually,the adaptability of fluorinated solvents to high voltages is critically determined by the degree of fluorination and the fluorination site,yet lacks systematic design principles.Herein,we introduce a solvent screening descriptor based on ionization energy and Fukui function to assess molecular and site-specific reactivity.Computational and experimental results demonstrate that an optimal solvent with low ground-state energies and reactive sites is required as an ideal candidate for high-voltage electrolytes.Among derivatives from anisole,(trifluoromethoxy)benzene is identified as a superior candidate,enabling the formulation of a low reactivity solution(LPT)as electrolyte.Remarkably,the prepared Li‖LCO cell using LPT electrolyte maintained a high-capacity retention of 78.8%after 600 cycles at 4.5 V.In addition,the formation of an inorganic-rich interphase from LPT electrolyte effectively suppresses structural degradation to ensure a fast dynamic behavior.The utilization of LPT electrolyte also greatly reduces the amount of heat released and the production of O_(2)gas,which is favorable for addressing thermal runaway hazards.This screening strategy offers a practical approach for the design of flame-retardant high-voltage electrolytes.
基金National Science & Technology Major Project of China(Grant No.2009ZX09501-002)National Natural Science Foundation of China(Grant No.20802006).
文摘Based on the density functional theory,we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons.Descriptors including global softness,Fukui function,local softness and local mulliken charge were calculated at SVWN/DN~* level of DFT with PC Spartan Pro.Nucleophilicity and basicity of 28 selected compounds were classified based on intensity.BP algorithm of artificial neural network(ANN) was employed to study the relationship between the descriptors and nucleophilicity/basicity.Cross-validation was carried out to avoid the over-fitting in training of ANN.A BP network was trained to quantify the relationship between HSAB-theory-based properties and nucleophilicity/basicity of compounds with lone-pair electrons.The results show that the prediction based on the network matches with the experimental results well.The local softness and Fukui function have a better relationship with nucleophilicity and local mulliken charge than with the basicity.The trained BP network could be utilized for predicting the nucleophilicity/basicity of compounds or functional groups with lone-pair electrons.
基金Foundation items： National Science ＆ Technology Major Project of China （Grant No. 2009ZX09501-002）, National Natural Science Foundation of China （Grant No. 20802006）.
文摘Based on the density functional theory, we described here a method to investigate the quantitative relationship between nucleophilicity/basicity and HSAB-theory-based properties of compounds with lone-pair electrons. Descriptors including global softness, Fukui function, local softness and local mulliken charge were calculated at SVWN/DN＊ level of DFT with PC Spartan Pro. Nucleophilicity and basicity of 28 selected compounds were classified based on intensity. BP algorithm of artificial neural network （ANN） was employed to study the relationship between the descriptors and nucleophilicity/basicity. Cross-validation was carried out to avoid the over-fitting in training of ANN. A BP network was trained to quantify the relationship between HSAB-theory-based properties and nucleophilicity/basicity of compounds with lone-pair electrons. The results show that the prediction based on the network matches with the experimental results well. The local softness and Fukui function have a better relationship with nucleophilicity and local mulliken charge than with the basicity. The trained BP network could be utilized for predicting the nucleophilicity/basicity of compounds or functional groups with lone-pair electrons.
基金FONDECYT grants 1140313 and 11150164.CC and PFFinanciamiento Basal para CentrosCientíficos y Tecnológicos de Excelencia-FB0807+2 种基金project RC-130006 CILISthe Fondo de Innovación para la Competitividad del Ministeriode Economía,Fomento y Turismo de Chile.MMCONICYT through grant 21130691.
文摘Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate states.Spatialpseudo-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended systems.Given the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited states.Here we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of states.The local softness is approximately equal to the density of states at the Fermi level.However,such approximation leaves out the contribution of inner states.In order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is presented.Single wall capped carbon nanotubes(SWCCNT)illustrate the limitation of the frontier orbital theory in extended systems.Thus,we have used a C360 SWCCNT to test the proposed model and how it compares with available models based on the local density of states.Interestingly,a simple Hückel approximation captures the main features of chemical response of these systems.Our results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.
基金This research was supported by NSF （DMR- 0449633）. PPZ thanks the financial support by the National Natural Science Foundation of China （Grant No. 21403097） and the Fundamental Research Funds for the Central Universities （lzujbky-2014-182）. The authors would like to thank Dr. Shaoxin Feng for his technical supports on this project. TL also thanks Dr. Shubin Liu （UNC） for sharing his insights on DFT.
文摘Triacetone triperoxide （TATP） is more sensitive than diacetone diperoxide （DADP） in the solid-state explosion. To explain this reactivity difference, we analyzed the electronic structures and properties of the crystals of both compounds by using Ab initio method to calculate the structures of their individual molecules as well as their lattice structures and particularly calculating Nuclear Fukui function to gain insight into the sensitivity of the initial, rate-determining step of their decomposition. Our results indicate that TATP and DADP crystal structures exhibit significantly different electronic proper- ties. Most notably, the electronic structure of the TATP crystal shows asymmetry among its reactive oxygen atoms as supported by magnitudes of their nuclear Fukui functions. The greater explosion sensitivity of crystalline TATP may be attributed to the properties of its electronic structure. The electronic calculations provided valuable insight into the decomposition sensitivity difference between TATP and DADP crystals.
基金support from National Key Research and Development Program of China(2022YFC3202402)the Fundamental Research Funds for the Cornell University(B230205044)+2 种基金Natural Science Foundation of China(51979081,52100179)Fundamental Research Funds for the Central Universities(B200202103)PAPD,Postgraduate Research&Practice Innovation Program of Jiangsu Province.
文摘Atrazine(ATZ),as one of the most extensively employed organochlorine-based herbicides,exhibits persistence and environmental toxicity.Photocatalytic technology based on polymer carbon nitride is regarded as a sus-tainable and promising approach for the degradation of emerging organic pollutants.Regrettably,the inherent shortcomings of pure carbon nitride greatly limit its practical application.Herein,S-doped carbon nitride was elaborately constructed for efficient degradation of ATZ.The removal efficiency of ATZ by the optimal sample(0.052 min^(-1))is 3.25 times as that of pure carbon nitride(0.016 min^(-1)).Experiments and DFT calculations show that S doping optimizes electronic structure of carbon nitride,which significantly enhances the spatial separation and transfer efficiency of photogenerated electrons and holes.Moreover,the reactive sites and degradation paths of ATZ were predicted by Fukui function and LC-MS determination.Our work provides an effective approach for the design of efficient photocatalysts to achieve efficient environmental remediation.
