A two dimensional model approach for the photodetachment dynamics of closed shell an-ionic systems in presence of external light field have been proposed in the context of polar environmental media. The effects of str...A two dimensional model approach for the photodetachment dynamics of closed shell an-ionic systems in presence of external light field have been proposed in the context of polar environmental media. The effects of strong coupling between the solvent polarization and the extra charge in the system were studied by a simple model. The electronic states of con-cerned halide ions are represented by a two dimensional model Hamiltonian with a potential V（x,y）=-V0e^-σ（x^2＋y^2）. The time dependent Fourier grid Hamiltonian method have been used to follow the detachment process with fairly high intensities of light. The environmental effects on the dynamics are sought to be modeled by two different ways. The first one was the presence of polar solvents which perturb the energy levels of anionic systems by changing the effective potential surface and the second one was allowing the fluctuation of the well depth randomly to mimic the system in a more realistic view point. The average detachment rate constant is calculated as a function of important parameters of the used light field to explain the effects of solvent field on the dynamical behavior of dipole bound anionic system at least in a qualitative way.展开更多
Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer cell.Based on the different amounts of methanol and water during synth...Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer cell.Based on the different amounts of methanol and water during synthesis,isolation and purification of the cyclic peptides,molecular dynamics(MD) was employed to simulate the conformation of stylopeptide 1 in methanol and aqueous environments.The comparative results show that the backbone ring was more rigid in methanol than in water.In methanol,two β-turns and three hydrogen bonds were well conserved throughout the simulation,whereas no hydrogen bonds or turns were preserved in water.The activity difference of stylopeptide 1 seemed to be attributed to the solvent effect on its conformation.展开更多
In this work, the intra-EDA method, which is a recently developed energy decomposition analysis scheme for intramolecular non-covalent interaction is extended from gas phase to solvated environment. It is the first an...In this work, the intra-EDA method, which is a recently developed energy decomposition analysis scheme for intramolecular non-covalent interaction is extended from gas phase to solvated environment. It is the first analysis scheme that performs analysis for intramolecular interaction in solution. By fragmentation scheme, a molecule is divided into intramolecular interacting fragments and environmental fragments via single bond homolysis breaking. The solvent effect is taken into account by implicit solvation model. Intramolecular interaction free energy is estimated as the separated treatment of inter-fragment interactions in dielectric environment. The analysis results highlight the importance of solvent effects to intramolecular non-covalent interaction.展开更多
Mesoporous sulfonic acid catalysts(MSAC) are widely used in acid-catalyzed reactions, including biomass conversions with plenty of polar solvents and precursors. The catalytic efficiency of MSAC is greatly affected by...Mesoporous sulfonic acid catalysts(MSAC) are widely used in acid-catalyzed reactions, including biomass conversions with plenty of polar solvents and precursors. The catalytic efficiency of MSAC is greatly affected by the microenvironment around the sulfonic acid sites. In this review, the progress on modification of microenvironment of MSAC is reviewed over the past decade. Hydrophobic modification allows MSAC prevent the adhesion of water molecules onto sulfonic acid sites, to abate the risk of reduced acid strength and catalytic efficiency. In comparison, hydrophilic properties can bring positive effect on acidcatalyzed reactions with the aid of hydrophilic interaction between polar functional groups on MSAC and hydrophilic groups of specific substrates. Amphiphilic MSAC with tunable wettability for specific substrates and solvents tend to improve the efficiency in certain reactions with mixed solvents or reactants of different polarity, especially for biphasic systems of immiscible liquids. Furthermore, much attention has been attracted on modification of surface to simulate the microenvironment of homogeneous solvents and enzyme biocatalysts in recent research. New trends of this field are also highlighted.展开更多
Self-assembly of colloidal nanocrystals(NCs)into large-scale superlattices with complex and controllable structures has attracted extensive attention due to their collective properties and promising device application...Self-assembly of colloidal nanocrystals(NCs)into large-scale superlattices with complex and controllable structures has attracted extensive attention due to their collective properties and promising device applications.Plasmonic NCs are very popular for long-range ordered superstructures by virtue of their collective nanogaps for electromagnetic field enhancement,in particular bulk-scale single-layer assembly.Large-area two-dimensional(2D)quasinanosheets(QNSs)composed of mono-component Au NCs or multi-component Au@ZnS core-shell hetero-nanocrystals(HNCs)were successfully prepared,via careful solvent evaporation-induced interfacial self-assembly.The entire selfassembly process was carried out on the liquid-air surface and mediated simply by tuning the operating temperatures and concentrations of the NCs.Specifically,monolayer and double-layer 2D QNSs in tens of micrometers scale with different stacking models were fabricated by precisely controlling the solvent evaporation rate and colloidal concentration.展开更多
文摘A two dimensional model approach for the photodetachment dynamics of closed shell an-ionic systems in presence of external light field have been proposed in the context of polar environmental media. The effects of strong coupling between the solvent polarization and the extra charge in the system were studied by a simple model. The electronic states of con-cerned halide ions are represented by a two dimensional model Hamiltonian with a potential V（x,y）=-V0e^-σ（x^2＋y^2）. The time dependent Fourier grid Hamiltonian method have been used to follow the detachment process with fairly high intensities of light. The environmental effects on the dynamics are sought to be modeled by two different ways. The first one was the presence of polar solvents which perturb the energy levels of anionic systems by changing the effective potential surface and the second one was allowing the fluctuation of the well depth randomly to mimic the system in a more realistic view point. The average detachment rate constant is calculated as a function of important parameters of the used light field to explain the effects of solvent field on the dynamical behavior of dipole bound anionic system at least in a qualitative way.
基金Supported by Teaching and Research Award Program for Outstanding Young Teachers in High Education Institutions of Ministry of Education,China(No.NCET-05-0279)Liaoning Science and Technology Foundation,China(No.2005226008)
文摘Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer cell.Based on the different amounts of methanol and water during synthesis,isolation and purification of the cyclic peptides,molecular dynamics(MD) was employed to simulate the conformation of stylopeptide 1 in methanol and aqueous environments.The comparative results show that the backbone ring was more rigid in methanol than in water.In methanol,two β-turns and three hydrogen bonds were well conserved throughout the simulation,whereas no hydrogen bonds or turns were preserved in water.The activity difference of stylopeptide 1 seemed to be attributed to the solvent effect on its conformation.
基金supported by the National Natural Science Foundation of China (21373165, 21120102035, 21273176, 21290190)the Fundamental Research Funds for the Central Universities, China (20720150037)
文摘In this work, the intra-EDA method, which is a recently developed energy decomposition analysis scheme for intramolecular non-covalent interaction is extended from gas phase to solvated environment. It is the first analysis scheme that performs analysis for intramolecular interaction in solution. By fragmentation scheme, a molecule is divided into intramolecular interacting fragments and environmental fragments via single bond homolysis breaking. The solvent effect is taken into account by implicit solvation model. Intramolecular interaction free energy is estimated as the separated treatment of inter-fragment interactions in dielectric environment. The analysis results highlight the importance of solvent effects to intramolecular non-covalent interaction.
基金supported by the National Natural Science Foundation of China(21503024)the Jiangsu Province Science Foundation for Youth(BK20150264,BK20150261)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology(BM2012110)
文摘Mesoporous sulfonic acid catalysts(MSAC) are widely used in acid-catalyzed reactions, including biomass conversions with plenty of polar solvents and precursors. The catalytic efficiency of MSAC is greatly affected by the microenvironment around the sulfonic acid sites. In this review, the progress on modification of microenvironment of MSAC is reviewed over the past decade. Hydrophobic modification allows MSAC prevent the adhesion of water molecules onto sulfonic acid sites, to abate the risk of reduced acid strength and catalytic efficiency. In comparison, hydrophilic properties can bring positive effect on acidcatalyzed reactions with the aid of hydrophilic interaction between polar functional groups on MSAC and hydrophilic groups of specific substrates. Amphiphilic MSAC with tunable wettability for specific substrates and solvents tend to improve the efficiency in certain reactions with mixed solvents or reactants of different polarity, especially for biphasic systems of immiscible liquids. Furthermore, much attention has been attracted on modification of surface to simulate the microenvironment of homogeneous solvents and enzyme biocatalysts in recent research. New trends of this field are also highlighted.
基金supported by the National Natural Science Foundation of China(NSFC,51872030,51631001,21801015,21643003,51702016,51501010 and 21703219)the Fundamental Research Funds for the Central Universities+1 种基金Beijing Institute of Technology Research Fund Program for Young ScholarsJoint R&D Plan of HongKong,Macao,Taiwan and Beijing(Z191100001619002)。
文摘Self-assembly of colloidal nanocrystals(NCs)into large-scale superlattices with complex and controllable structures has attracted extensive attention due to their collective properties and promising device applications.Plasmonic NCs are very popular for long-range ordered superstructures by virtue of their collective nanogaps for electromagnetic field enhancement,in particular bulk-scale single-layer assembly.Large-area two-dimensional(2D)quasinanosheets(QNSs)composed of mono-component Au NCs or multi-component Au@ZnS core-shell hetero-nanocrystals(HNCs)were successfully prepared,via careful solvent evaporation-induced interfacial self-assembly.The entire selfassembly process was carried out on the liquid-air surface and mediated simply by tuning the operating temperatures and concentrations of the NCs.Specifically,monolayer and double-layer 2D QNSs in tens of micrometers scale with different stacking models were fabricated by precisely controlling the solvent evaporation rate and colloidal concentration.
