Coat protein(CP)is required for potyviruses to move and establish a systemic infection in plants.π-stackings formed by aromatic residues play critical roles in maintaining protein stability and functions.As we know,m...Coat protein(CP)is required for potyviruses to move and establish a systemic infection in plants.π-stackings formed by aromatic residues play critical roles in maintaining protein stability and functions.As we know,many aromatic residues located in the core region of potyvirus CPs are conserved.However,their roles in potyvirus infection remain largely unknown.Here,through analysis of the three-dimensional model of the tobacco vein banding mosaic virus(TVBMV;genus Potyvirus)CP,16 aromatic residues were predicated to formπ-stackings.The results of transient expression experiments demonstrated that deletion of any of these 16 aromatic residues reduced CP accumulation.Infectivity assays showed that deletion of any of these aromatic residues in the TVBMV infectious clone abolished cell-to-cell movement and reduced replication of the virus.Substitution of Y^(105) and Y^(147) individually with non-aromatic residues alanine or glycine reduced CP accumulation,virus replication,and abolished the ability of TVBMV to move intercellularly,while substitution of these two residues individually with aromatic residues phenylalanine or tryptophan,had no or little effect on CP accumulation and TVBMV systemic movement and replication.Similar results were obtained from the CP mutants of watermelon mosaic virus(WMV,genus Potyvirus).Taken together,our results demonstrate that multiple aromatic residues in CP are involved in potyvirus movement by formingπ-stackings to maintain CP accumulation.展开更多
The intermolecular interaction determines the photophysical properties of the organic aggregates,which are critical to the performance of organic photovoltaics.Here,excitonic coupling,an important intermolecular inter...The intermolecular interaction determines the photophysical properties of the organic aggregates,which are critical to the performance of organic photovoltaics.Here,excitonic coupling,an important intermolecular interaction in organic aggregates,between theπ-stacking graphene quantum dots is studied by using transient absorption spectroscopy.We find that the spectral evolution of the ground state bleach arises from the dynamic variation of the excitonic coupling in the excitedπ-stacks.According to the spectral simulations,we demonstrate that the kinetics of the vibronic peak can be exploited as a probe to measure the dynamics of excitonic coupling in the excitedπ-stacks.展开更多
Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is fur...Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is further utilized to efficiently construct [2]rotaxane.展开更多
The crystal structure of [Ni(C5H2N2O4)(2, 2?bipy)(H2O)2]?H2O 1 has been determined by X-ray diffraction. Crystal data: triclinic system, space group P with a = 7.9424(3), b = 9.9417(3), c = 12.1867(3) ? a = 84.771(1),...The crystal structure of [Ni(C5H2N2O4)(2, 2?bipy)(H2O)2]?H2O 1 has been determined by X-ray diffraction. Crystal data: triclinic system, space group P with a = 7.9424(3), b = 9.9417(3), c = 12.1867(3) ? a = 84.771(1), b = 77.375(2), g = 68.993(2)? C15H18N4O8Ni, Mr = 440.7, V = 876.16(5) 3, Z = 2, Dc = 1.672 g/cm3, F(000) = 456, m(MoKa) = 1.162 mm-1, the final R = 0.0464 and wR = 0.1055 for 3026 observed reflections with I > 2s(I). In the title compound, the nickel ion is coordinated by a nitrogen atom and an oxygen atom from the orotate ligand, two nitrogen atoms from 2, 2?bipy and two oxygen atoms from the coordinated water molecules in a distorted octahedral geometry. The presence of intermolecular hydrogen bonding and p-p stacking interaction of aromatic rings from 2, 2?bipy results in a 3D structure.展开更多
Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A ...Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A architectures are constructed on various scaffolds,which have either a long D/A distance or permitted conrotatory motion.Here,we develop a novel spiro-based scaffold with a short D/A distance and restricted circumvolution motions because of both the rigid spiro-scaffold and large rotation hindrance between the nearly coplanar D and A.We append different alkyl chains,which can modulate charge transfer and luminescence properties,at the nitrogen of the D moiety to develop four TADF molecules,which can modulate chargetransfer and luminescence properties.Because of the introduction of the solubilized alkyl chain,these molecules were used to fabricate solutionprocessed devices,among which a maximum external quantum efficiency of 18.9%was realized.By modulating interactions between the D/A building blocks,these TADF constructs exemplify that the alkyl side chains of TADF molecules,which used to be considered as solubilizing units,have vital impact on the optoelectronic properties and thus offer a new route to the design of solution-processable TADF emitters.展开更多
Supramolecular self-assembly in water based on non-covalent bonding is attracting major attention due to the potential of hydrogels and aqueous polymers in biomedical applications.Although supramolecular polymerizatio...Supramolecular self-assembly in water based on non-covalent bonding is attracting major attention due to the potential of hydrogels and aqueous polymers in biomedical applications.Although supramolecular polymerization in organic solvents is well established,the key design features,the assembly mechanisms in water and achieving control over the aggregate structures remain challenging.Here,we present the assembly and disassembly of geometrical isomers of a stiff-stilbene bis-urea amphiphile(SA)in pure water.A remarkable feature of this system is that the(E)-isomer forms supramolecular polymers in both pure water and organic solvents.Taking advantage of this unique property,the hydrophobic effect was studied by comparing the supramolecular assembly in both systems.The assembly process inwater follows an enthalpy-driven nucleation-elongation(cooperative)supramolecular polymerization mechanism with a standard Gibbs free energy(ΔG°=−53 kJ mol^(−1))double the value of the one found in toluene.We attributed this distinctive feature to the hydrophobic effect in water.Furthermore,we discovered an isomer-dependent assembly process,which can be used to control aggregation in aqueous media.Due to the substantial geometric difference between(E)-SA and(Z)-SA,we compared their assembly in water to study the influence of different driving forces involved in the process.The supramolecular polymerization of(E)-SA was cooperatively influenced by hydrogen bonding,π-stacking,and hydrophobic effects,whereas the assembly of(Z)-SAwasmainly driven by hydrophobic effects.As a result,the fiber length of(E)-SA in water is much longer than that of(Z)-SA,presenting opportunities for geometrical control of aggregation in aqueousmedia.展开更多
Tetraphenylethylene(TPE)-conjugated porphyrin TPE-ZnPF is synthesized in high yield and characterized by single-crystal X-ray diffraction.The propeller-shaped TPE groups not only enable exceptional aggregation-induced...Tetraphenylethylene(TPE)-conjugated porphyrin TPE-ZnPF is synthesized in high yield and characterized by single-crystal X-ray diffraction.The propeller-shaped TPE groups not only enable exceptional aggregation-induced emission(AIE)in the solid state but also abolish the strongπ-πstacking of porphyrin moieties and thus prohibit aggregation-caused quenching(ACQ).TPE-ZnPF aggregates feature longlived photoexcited states,which subsequently suppress non-radiative decay channels and enhance emission intensity.Moreover,its aggregates show more efficient lightharvesting ability due to the Förster resonance energy transfer from the TPE energy donor to the porphyrin core energy acceptor,well-defined nanosphere morphology,and more efficient photoinduced charge separation than the porphyrin Ph-ZnPF,which possesses ACQ and agglomerated morphology.As a result,an excellent photocatalytic hydrogen evolution rate(ηH_(2))of 56.20 mmol g^(‒1)h^(‒1)is recorded for TPE-ZnPF aggregates,which is 94-fold higher than that of the aggregates of Ph-ZnPF(0.60 mmol g^(‒1)h^(‒1))without the TPE groups.展开更多
基金supported by grants from the National Natural Science Foundation of China(NSFC31720103912,31871933)+1 种基金‘Taishan Scholar’Construction Project(TS201712023)Funds of Shandong‘Double Tops’Program(SYL2017XTTD11).
文摘Coat protein(CP)is required for potyviruses to move and establish a systemic infection in plants.π-stackings formed by aromatic residues play critical roles in maintaining protein stability and functions.As we know,many aromatic residues located in the core region of potyvirus CPs are conserved.However,their roles in potyvirus infection remain largely unknown.Here,through analysis of the three-dimensional model of the tobacco vein banding mosaic virus(TVBMV;genus Potyvirus)CP,16 aromatic residues were predicated to formπ-stackings.The results of transient expression experiments demonstrated that deletion of any of these 16 aromatic residues reduced CP accumulation.Infectivity assays showed that deletion of any of these aromatic residues in the TVBMV infectious clone abolished cell-to-cell movement and reduced replication of the virus.Substitution of Y^(105) and Y^(147) individually with non-aromatic residues alanine or glycine reduced CP accumulation,virus replication,and abolished the ability of TVBMV to move intercellularly,while substitution of these two residues individually with aromatic residues phenylalanine or tryptophan,had no or little effect on CP accumulation and TVBMV systemic movement and replication.Similar results were obtained from the CP mutants of watermelon mosaic virus(WMV,genus Potyvirus).Taken together,our results demonstrate that multiple aromatic residues in CP are involved in potyvirus movement by formingπ-stackings to maintain CP accumulation.
基金supported by the National Natural Science Foundation of China (No.22175145 and No.21771155)
文摘The intermolecular interaction determines the photophysical properties of the organic aggregates,which are critical to the performance of organic photovoltaics.Here,excitonic coupling,an important intermolecular interaction in organic aggregates,between theπ-stacking graphene quantum dots is studied by using transient absorption spectroscopy.We find that the spectral evolution of the ground state bleach arises from the dynamic variation of the excitonic coupling in the excitedπ-stacks.According to the spectral simulations,we demonstrate that the kinetics of the vibronic peak can be exploited as a probe to measure the dynamics of excitonic coupling in the excitedπ-stacks.
基金the financial support of NNSF of China(Nos.21402069 and 21361011)the Project of Jiangxi Provincial Education Department(No.GJJ14264)
文摘Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is further utilized to efficiently construct [2]rotaxane.
基金This project was supported by the Natural Science Foundation of China and Chinese Academy of Sciences
文摘The crystal structure of [Ni(C5H2N2O4)(2, 2?bipy)(H2O)2]?H2O 1 has been determined by X-ray diffraction. Crystal data: triclinic system, space group P with a = 7.9424(3), b = 9.9417(3), c = 12.1867(3) ? a = 84.771(1), b = 77.375(2), g = 68.993(2)? C15H18N4O8Ni, Mr = 440.7, V = 876.16(5) 3, Z = 2, Dc = 1.672 g/cm3, F(000) = 456, m(MoKa) = 1.162 mm-1, the final R = 0.0464 and wR = 0.1055 for 3026 observed reflections with I > 2s(I). In the title compound, the nickel ion is coordinated by a nitrogen atom and an oxygen atom from the orotate ligand, two nitrogen atoms from 2, 2?bipy and two oxygen atoms from the coordinated water molecules in a distorted octahedral geometry. The presence of intermolecular hydrogen bonding and p-p stacking interaction of aromatic rings from 2, 2?bipy results in a 3D structure.
基金This project was also funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology and by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and the 111 Project.G.X.acknowledges the fundamental Research Funds for the Central Universities of China(no.2042019kf0234).
文摘Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A architectures are constructed on various scaffolds,which have either a long D/A distance or permitted conrotatory motion.Here,we develop a novel spiro-based scaffold with a short D/A distance and restricted circumvolution motions because of both the rigid spiro-scaffold and large rotation hindrance between the nearly coplanar D and A.We append different alkyl chains,which can modulate charge transfer and luminescence properties,at the nitrogen of the D moiety to develop four TADF molecules,which can modulate chargetransfer and luminescence properties.Because of the introduction of the solubilized alkyl chain,these molecules were used to fabricate solutionprocessed devices,among which a maximum external quantum efficiency of 18.9%was realized.By modulating interactions between the D/A building blocks,these TADF constructs exemplify that the alkyl side chains of TADF molecules,which used to be considered as solubilizing units,have vital impact on the optoelectronic properties and thus offer a new route to the design of solution-processable TADF emitters.
基金Financial support from the Netherlands Organization for Scientific Research(NWO-CW)the European Research Council(ERC,advanced grant no.694345 to B.L.F.)+2 种基金the Dutch Ministry of Education,Culture and Science(Gravitation program no.024.001.035)the China Scholarship Council(CSC,no.201707040064 to F.X.)the Marie Skłodowska-Curie Actions(Individual Fellowships no.838280 to S.C.and no.793082 to L.P.)is gratefully acknowledged.
文摘Supramolecular self-assembly in water based on non-covalent bonding is attracting major attention due to the potential of hydrogels and aqueous polymers in biomedical applications.Although supramolecular polymerization in organic solvents is well established,the key design features,the assembly mechanisms in water and achieving control over the aggregate structures remain challenging.Here,we present the assembly and disassembly of geometrical isomers of a stiff-stilbene bis-urea amphiphile(SA)in pure water.A remarkable feature of this system is that the(E)-isomer forms supramolecular polymers in both pure water and organic solvents.Taking advantage of this unique property,the hydrophobic effect was studied by comparing the supramolecular assembly in both systems.The assembly process inwater follows an enthalpy-driven nucleation-elongation(cooperative)supramolecular polymerization mechanism with a standard Gibbs free energy(ΔG°=−53 kJ mol^(−1))double the value of the one found in toluene.We attributed this distinctive feature to the hydrophobic effect in water.Furthermore,we discovered an isomer-dependent assembly process,which can be used to control aggregation in aqueous media.Due to the substantial geometric difference between(E)-SA and(Z)-SA,we compared their assembly in water to study the influence of different driving forces involved in the process.The supramolecular polymerization of(E)-SA was cooperatively influenced by hydrogen bonding,π-stacking,and hydrophobic effects,whereas the assembly of(Z)-SAwasmainly driven by hydrophobic effects.As a result,the fiber length of(E)-SA in water is much longer than that of(Z)-SA,presenting opportunities for geometrical control of aggregation in aqueousmedia.
基金RGC Senior Research Fellowship Scheme,Grant/Award Number:SRFS2021-5S01National Natural Science Foundation of China,Grant/Award Number:52073242+4 种基金Hong Kong Polytechnic University,Grant/Award Number:YXA2Research Institute for Smart Energy,Grant/Award Number:CDAQMiss Clarea Au for the Endowed Professorship in Energy,Grant/Award Number:847SGeneral Research Fund,Grant/Award Numbers:HKBU 12304320,N_HKBU213/22Hong Kong Research Grants Council,and Initiation Grant for Faculty Niche Research Areas(IG-FNRA),Grant/Award Number:2020/21。
文摘Tetraphenylethylene(TPE)-conjugated porphyrin TPE-ZnPF is synthesized in high yield and characterized by single-crystal X-ray diffraction.The propeller-shaped TPE groups not only enable exceptional aggregation-induced emission(AIE)in the solid state but also abolish the strongπ-πstacking of porphyrin moieties and thus prohibit aggregation-caused quenching(ACQ).TPE-ZnPF aggregates feature longlived photoexcited states,which subsequently suppress non-radiative decay channels and enhance emission intensity.Moreover,its aggregates show more efficient lightharvesting ability due to the Förster resonance energy transfer from the TPE energy donor to the porphyrin core energy acceptor,well-defined nanosphere morphology,and more efficient photoinduced charge separation than the porphyrin Ph-ZnPF,which possesses ACQ and agglomerated morphology.As a result,an excellent photocatalytic hydrogen evolution rate(ηH_(2))of 56.20 mmol g^(‒1)h^(‒1)is recorded for TPE-ZnPF aggregates,which is 94-fold higher than that of the aggregates of Ph-ZnPF(0.60 mmol g^(‒1)h^(‒1))without the TPE groups.
