A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for hi...A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.展开更多
Squaraine （SQ） dyes have been considered as efficient photoactive materials for organic solar cells. In this work, we purposely controlled the molecular aggregation of an SQ dye, 2,4-bis[4-（N,N-dibutylamino）-2-dih...Squaraine （SQ） dyes have been considered as efficient photoactive materials for organic solar cells. In this work, we purposely controlled the molecular aggregation of an SQ dye, 2,4-bis[4-（N,N-dibutylamino）-2-dihydroxyphenyl] SQ （DBSQ- （OH）2） in the DBSQ（OH）2：[6,6]-phenyl-Cel-butyric acid methyl ester （PCBM） blend film by using the thermal annealing method, to study the influence of the molecular aggregation on film properties as well as the photovoltaic performance of DBSQ（OH）2：PCBM-based bulk heterojunction （BHJ） solar cells. Our results demonstrate that thermal annealing may change the aggregation behavior of DBSQ（OH）2 in the DBSQ（OH）2：PCBM film, and thus significantly influence the surface morphology, optical and electrical properties of the blend film, as well as the photovoltaic performance of DBSQ（OH）2：PCBM BHJ cells.展开更多
A β cyclodextrin derivative bearing seven cationic arms and its singly charged analogue, i.e., per-6- deoxy-f-（1-methylimidazol-3-ium-3-yl）-β-cyclodextrin （3） and mono-fi-deoxy-6-（1-methylimidazol- 3-ium-3-yl）...A β cyclodextrin derivative bearing seven cationic arms and its singly charged analogue, i.e., per-6- deoxy-f-（1-methylimidazol-3-ium-3-yl）-β-cyclodextrin （3） and mono-fi-deoxy-6-（1-methylimidazol- 3-ium-3-yl）-β-cyclodextrin （4） were synthesized and fully characterized. Their induced aggregation behaviours towards two anionic surfactant, that is, sodium dodecyl sulfonate （SDS） and dioctyl sodium sulfosuccinate （Aerosol OT, AOT）, were investigated by UV-vis, NMR, Zeta-potential, dynamic light scattering （DLS）, and transmission electron microscopy. The results revealed that host 3 can induce the molecular aggregation of anionic surfactant at concentration far lower than its original CAC, leading to the larger diameter, the narrower size distribution and the higher thermal stability of the induced aggregate towards the anionic surfactant possessing more hydrophobic tails.展开更多
A widely-used naphthalenediimide （NDI） based electron acceptor P（NDI2OD-T2） with different number- average molecular weight （Mn） of 38 （N2200L）, 56 （N2200M）, 102 （N2200H） kDa were successfully prepared. Th...A widely-used naphthalenediimide （NDI） based electron acceptor P（NDI2OD-T2） with different number- average molecular weight （Mn） of 38 （N2200L）, 56 （N2200M）, 102 （N2200H） kDa were successfully prepared. The effect of molecular-weight on the performance of all-polymer solar cells based on Poly（5-（5-（4,8- bis（ 5-decylthiophen-2-yl ）-6-methylbenzo[1,2-b： 4,5-b＇]dithophen-2-yl ）thiophen-2-yl ）-6,7-difluoro-8- （5-methylthiophen-2-yl）-2,S-bis（3-（octyloxy）phenyl）quinoxaline） （P2F-DE）：N2200 was systematically investigated. The results reveal that N2200 with increased M. show enhanced intermolecular interac- tions, resulting in improved light absorption and electron mobility. However, the strong aggregation trend of N2200H can cause unfavorable morphology for exciton dissociation and carrier transport. The blend film using N2200 with moderate M. actually develops more ideal phase segregation for efficient charge separation and transport, leading to balanced electron/hole mobility and less carrier recombi- nation. Consequently, all-polymer solar cells employing P2F-DE as the electron donor and N2200M as the electron acceptor show the highest efficiency of 4.81%, outperforming those using N2200L （3,07~;） and N2200H （S,92%）. Thus, the Mn of the polymer acceptor plays an important role in all-polymer solar ceils, which allows it to be an effective parameter for the adjustment of the device morphology and efficiency.展开更多
Regioregular poly(3-hexylthio)thiopene(P3HTT) has emerged tremendous potential in organic electronic applications due to the strong noncovalent interactions from the sulfur atom linked to thiophene. However, P3HTT gen...Regioregular poly(3-hexylthio)thiopene(P3HTT) has emerged tremendous potential in organic electronic applications due to the strong noncovalent interactions from the sulfur atom linked to thiophene. However, P3HTT generally exhibits low charge mobility mostly due to poor solution processability attributed to dense arrangement of hexylthio side chain in polymer, which led to strong noncovalent interactions among sulfur atoms. To balance the nonvalent interaction and aggregation for P3HTT, herein, we systematically study the effect of hexylthio side chain content in polymer backbone on the structure and properties. A series of regioregular P3HTT-based homopolymers(P3HTT, P3HTT-50,P3HTT-33 and P3HTT-25) were prepared via Kumada catalyst transfer polycondensation method from a set of mono-, bi-, ter-and quarterthiophenes containing different contents of hexylthio side chain. The DFT calculation shows the planarity of polymers backbone could be improved through reducing the density of hexylthio side chain in polymer mainchain. And significant changes in their crystallinity, aggregation and optical properties were observed with the content of hexylthio side chain reducing. The P3HTT-33 displayed the highest field-effect transistor hole mobility of 2.83×10^(-2) cm^(2)·V^(-1)·s^(-1) resulting from a balance between the crystallinity and planarity. This study demonstrates modulating the content of hexylthio side chain in P3HTT is an effective strategy to optimize the opto-electronic properties of polymer obtaining excellent semiconductor device performance.展开更多
Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiment...Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiments and molecular dynamics numerical simulations were conducted to investigate the effects of changes in shale oil composition on macroscopic fluidity.The concept of“component flow”for shale oil was proposed,and the formation mechanism and conditions of component flow were discussed.The research reveals findings in four aspects.First,a miscible state of light,medium and heavy hydrocarbons form within micropores/nanopores of underground shale according to similarity and intermiscibility principles,which make components with poor fluidity suspended as molecular aggregates in light and medium hydrocarbon solvents,such as heavy hydrocarbons,thereby decreasing shale oil viscosity and enhancing fluidity and outflows.Second,small-molecule aromatic hydrocarbons act as carriers for component flow,and the higher the content of gaseous and light hydrocarbons,the more conducive it is to inhibit the formation of larger aggregates of heavy components such as resin and asphalt,thus increasing their plastic deformation ability and bringing about better component flow efficiency.Third,higher formation temperatures reduce the viscosity of heavy hydrocarbon components,such as wax,thereby improving their fluidity.Fourth,preservation conditions,formation energy,and production system play important roles in controlling the content of light hydrocarbon components,outflow rate,and forming stable“component flow”,which are crucial factors for the optimal compatibility and maximum flow rate of multi-component hydrocarbons in shale oil.The component flow of underground shale oil is significant for improving single-well production and the cumulative ultimate recovery of shale oil.展开更多
Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow t...Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow the mechanical ductility of active layers,the photovoltaic efficiencies usually drops in the resulting OSCs.Herein,a high photovoltaic efficiency of 15.03%and a large crack-onset strain of 15.70%is simultaneously achieved based on a ternary blend consisting of polymer donor poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))](PM6),non-fullerene accepter 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(Y6),and soft elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene(SEBS)through the control of phase separation and crystallization.By employing a high-boiling point solvent additive 1-chloronaphthalene(CN)with different solubilities for PM6 and Y6,the aggregation dynamics of PM6 and Y6 as well as the film solidification process are dramatically altered,allowing for the different molecular rearrangement and liquid-liquid phase separation evolution.Consequently,the ternary film with optimal CN content presents decreased SEBS domains and moderately improved molecular ordering of PM6 and Y6,enabling effective mechanical deformation and charge generation/transport.The revealed corrections between the film-formation process,film microstructure,and photovoltaic/mechanical characteristics in the ternary blend provide deep understanding of the morphology control toward high-performance stretchable OSCs.展开更多
Salt stress remains a significant challenge for crop growth and food security.The development of effective analytical tools for salt stress-related studies is of great importance.Recently,Yang and Yin et al.have devel...Salt stress remains a significant challenge for crop growth and food security.The development of effective analytical tools for salt stress-related studies is of great importance.Recently,Yang and Yin et al.have developed a novel biosensor that effectively traces salt stress in plants,based on salt-induced molecular J-aggregation and the corresponding changes in fluorescence signals.展开更多
We present a study of spectroscopic identification towards the molecular aggregates of zinc tetraphenylporphyrin （ZnTPP） illustrating how the energy states and intermolecular interactions determine the tunable prope...We present a study of spectroscopic identification towards the molecular aggregates of zinc tetraphenylporphyrin （ZnTPP） illustrating how the energy states and intermolecular interactions determine the tunable properties of functional materials in condensation processes. Distinguishable fingerprints of ZnTPP nanorods and nanosheets are addressed utilizing X-ray diffraction （XRD）, Raman and UV-vis absorption spectroscopies. Although these ZnTPPs are assigned to J-aggregation at different extent, the spectral analysis reveals a significant role of the intermolecular interactions associated with varying mesoscale architectures. Energy decomposition analysis （EDA） revealed that the varied ZnTPP aggregates are stabilized by altered dispersion interactions due to the dominant ~r...zr stacking between the monomers.展开更多
To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simul...To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simultaneously.Four-in-one molecular aggregates were prepared to implement this strategy,which comprised of Pro and Eto with the bridging molecule monoglyceride monooleate(GMO)and sur-factant F127 through intermolecular forces.The blood-brain barrier(BBB)targeted lactoferrin(LF)is affixed to their surface,obtaining thefinal molecular aggregates.By employing lactoferrin enrich aggregates to the BBB,followed by ultrasound combine microbubbles to open the BBB,a remarkable 4.5-fold enhancement in brain drug delivery was achieved.The molecular aggregates group maintained sta-ble parameters of heart rate,diastolic blood pressure,and systolic blood pressure.A notable increase of more than twice therapeutic index(TI)value was observed,implying their higher anesthesia efficiency and reduced toxicity.Electroencephalo-gram(EEG)experiments demonstrate a significant elevation in the proportion of θ waves from 28%to 80%for aggregates,accompanied by a nearlyfivefold reduc-tion in the proportion ofθwaves,meaning a significant improvement in synergistic anesthesia effectiveness(interaction index 0.289)with lower drug dosage.Further-more,mouse immunofluorescence brain slice experiments suggest Pro and Eto enter the GABA receptor simultaneously,resulting in synergistic inhibition of GABA receptors.展开更多
Intermolecular charge transfer(inter-CT)is commonly considered to quench luminescence in molecular aggregates,especially for near-infrared(NIR)emission.Herein,by elaborate comparison ofπ-bridge effects in donor/accep...Intermolecular charge transfer(inter-CT)is commonly considered to quench luminescence in molecular aggregates,especially for near-infrared(NIR)emission.Herein,by elaborate comparison ofπ-bridge effects in donor/acceptor(D/A)molecules,it is disclosed that aπ-bridge is essential in D/A molecule to involve inter-CT in aggregates for inducing desired thermally activated delayed fluorescence(TADF)and largely suppressing non-radiative decays,and importantly,electrondonatingπ-bridge is critical to maximize radiative decay for inter-CT dominated emission by effective electronic coupling with bright intramolecular charge transfer(intra-CT)for high-efficiency NIR emission.As a proof-of-concept,TPATAP with thienyl asπ-bridge realized prominent photoluminescence quantum yields of 18.9%at 788 nm in solid films,and achieved record-high maximum external quantum efficiencies of 4.53%at 785 nm in devices.These findings provide fresh insight into interplay between inter-CT and intra-CT in molecular aggregates and open a new avenue to attenuate the limitation of energy gap law for developing highly efficient NIR emitters and improving the luminescent efficiency of various inter-CT systems,such as organic photovoltaic,organic long persistent luminescence,etc.展开更多
CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes ...CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes the essential role of noncovalent interactions,particularly in peptide-based materials.Key forces,such as aromatic stacking and hydrogen bonding,are crucial for promoting molecular aggregation and stabilizing supramolecular structures.Numerous studies demonstrate how these interactions influence the phase transitions and the morphology of self-assembled structures.Recent advances in computational methodologies,including molecular dynamics simulations and machine learning,have significantly enhanced our understanding of self-assembly processes.These tools enable researchers to predict how molecular properties,such as hydrophobicity,charge distribution,and aromaticity,affect assembly behavior.Simulations uncover the energetic landscapes governing peptide aggregation,providing insights into the kinetic pathways and thermodynamic stabilities.Meanwhile,machine learning facilitates the rapid screening of peptide libraries,identifying sequences with optimal self-assembly characteristics,and accelerating material design with tailored functionalities.Beyond their structural and physicochemical properties,self-assembled peptide nanostructures hold immense potential in biological applications due to their versatility and biocompatibility.By manipulating molecular interactions,researchers have engineered responsive systems that interact with cellular environments to elicit specific biological responses.These peptide nanostructures can mimic extracellular matrices,facilitating cell adhesion,proliferation,and differentiation.They also show promise in modulating immune responses,recruiting immune cells,and regulating signaling pathways,making them valuable tools in immunotherapy and regenerative medicine.Moreover,their ability to disrupt bacterial membranes positions them as innovative alternatives to conventional antibiotics,addressing the urgent need for solutions to antimicrobial resistance.Despite its promise,peptide self-assembly faces several challenges.The assembly process is highly sensitive to environmental conditions,such as pH,temperature,and ionic strength,leading to variability in the morphology and properties.Furthermore,peptide aggregation can result in heterogeneous and poorly defined assemblies,complicating the reproducibility and scalability.Designing peptides with predictable self-assembly behavior remains a significant hurdle.Looking ahead,integrating computational predictions with experimental validations will be crucial in discovering novel peptide sequences with tailored self-assembly properties.Machine learning,combined with high-throughput screening techniques,will enable the rapid identification of optimal peptide sequences.In situ characterization tools,such as cryoelectron microscopy and advanced spectroscopy,will provide deeper insights into assembly mechanisms,aiding the rational design of peptide materials.As research progresses,the dynamic and reversible nature of noncovalent interactions can be leveraged to create adaptive responsive to environmental stimuli.Self-assembled peptide nanostructures are poised for impactful applications in biomedicine including targeted drug delivery,tissue repair,and advanced therapeutic strategies.Ultimately,these nanostructures represent a powerful platform for addressing complex challenges in biomedicine and beyond,paving the way for transformative breakthroughs in science and technology.展开更多
While chirality is a prevalent character of numerous biological and synthetic organic molecules,its selective absorption of circularly polarized light,known as circular dichroism(CD),is typically small due to intrinsi...While chirality is a prevalent character of numerous biological and synthetic organic molecules,its selective absorption of circularly polarized light,known as circular dichroism(CD),is typically small due to intrinsically weak coupling between magnetic and electric dipoles.However,thin films of aggregated,enantiopure prolinol-derived squaraine molecules(ProSQ-C16)exhibit an unusually large excitonic CD signal,although the underlying mechanism is not yet known.In this study,we employ steady-state and ultrafast transient absorption spectroscopy to investigate the nature and dynamics of excitons in aggregates of enantiopure and racemic ProSQ-C16 thin films.Highly resembling transient responses of enantiopure thin films under excitations at different photon energies strongly indicate that a single type of aggregate dominates the linear optical response,that is,a strong red-shifted(J-like)and weak blue-shifted(H-like)absorption band.On the other hand,the transient properties of the racemic thin film deviate from this pattern and remain largely ambiguous.The short lifetime of excited states and coherent oscillations present in the dynamics of the transient absorption signal indicate that the early time dynamics are governed by a transition towards a dark intermediate state,which might arise from intermolecular charge transfer with potential contributions from the coupling of excitons to the vibrations.This non-radiative relaxation pathway explains the unusually weak fluorescence of the predominately J-like behaving aggregate.Our findings conclusively show that the chiral aggregate structure has a strong impact on the optical and dynamic response of the excitons and underline the significance of non-Frenkel exciton states for the optical properties of anilino squaraine dyes.展开更多
We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on ...We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on theoretical investigation of the electronic structures and dynamic processes upon photo-and electric-excitation for molecules and aggregates. We aim to develop reliable methodology to predict the optoelectronic properties of molecular materials related to the electronic excitations and to apply in the experiments. We identify two essential scientific challenges: (i) nature of intramolecular and intermolecular electronic excited states; (ii) theoretical description of the dynamic processes of the coupled motion of electronic excitations and nucleus. We propose the following four subjects of research: (i) linear scaling time-dependent density-functional theory and its application to open shell system; (ii) computational method development of electronic excited state for molecular aggregates; (iii) theoretical investigation of the time evolution of the excited state dynamics; (iv) methods to predict the optoelectronic properties starting from electronic excited state investigation for organic materials and experimental verifications.展开更多
This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodolo...This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodology development is especially based on the time-dependent density functional theory (TDDFT) and valence bond (VB) theory, and is expected to be computationally effective and accurate as well. Research works on the following related subjects will be performed: (1) The analytical energy-derivative approaches for electronically excited state within TDDFT will be developed to reduce bypass the computational costs in the calculation of molecular excited-state properties. (2) The ab initio methods for electronically excited state based on VB theory and hybrid TDDFT-VB method will be developed to overcome the limitations of current TDDFT in simulating photophysics and photochemistry. (3) For larger aggregates, neither ab initio methods nor TDDFT is applicable. We intend to build the effective model Hamiltonian by developing novel theoretical and computational methods to calculate the involved microscopic physical parameters from the first-principles methods. The constructed effective Hamiltonian is then used to describe the excitonic states and excitonic dynamics of the natural or artificial photosynthesized systems, organic or inorganic photovoltaic cell. (4) The condensed phase environment is taken into account by combining the developed theories and algorithms based on TDDFT and VB with the polarizable continuum solvent models (PCM), molecular mechanism (MM), classical electrodynamics (ED) or molecular dynamics (MD) theory. (5) Highly efficient software packages will be designed and developed.展开更多
Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to...Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to decelerate k_(nr) are mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small k_(nr) for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.展开更多
This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Pr...This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". This study will focus on developments of novel methods to simulate excited state dynamics of molecular aggregates, with the aim of understanding several important chemical physics processes, and providing a solid foundation for predicting the opto-electronic properties of organic functional materials and devices. The contents of this study include: (1) The quantum chemical methods for electronic excited state and electronic couplings targeted for dynamics in molecular aggregates; (2) Methods to construct effective Hamiltonian models, and to solve their dynamics using system-bath approaches; (3) Non-adiabatic mixed quantum-classic methods targeted for molecular aggregates; (4) Theoretical studies of charge and energy transfer, and related spectroscopic phenomena in molecular aggregates.展开更多
Molecular aggregates are receiving tremendous attention,demonstrating immense potential for biomedical applications in vitro and in vivo.For instance,the molecular aggregates of conventional fluorophores influence the...Molecular aggregates are receiving tremendous attention,demonstrating immense potential for biomedical applications in vitro and in vivo.For instance,the molecular aggregates of conventional fluorophores influence the electronic excitation states of the aggregates,causing characteristic photophysical property changes.A fundamental understanding of this classical relationship between molecular aggregate structures and photophysics has allowed for innovative biological applications.The chemical characteristics of drug molecules generally trigger the formation of colloidal aggregates,and this is considered detrimental to the drug discovery process.Furthermore,nano-sized supramolecular aggregates have been used in biomedical imaging and therapy owing to their optimal properties for in vivo utility,including enhanced cell permeability,passive tumor targeting,and convenient surface engineering.Herein,we provide an overview of the recent trends in molecular aggregates for biomedical applications.The changes in photophysical properties of conventional fluorophores and their biological applications are discussed,followed by the effects of conventional drug molecule-aggregates on drug discovery and therapeutics development.Recent trends in the investigation of biologically important analytes with aggregation-induced emission are discussed for conventional and unconventional fluorophores.Lastly,we discuss nano-sized supramolecular aggregates used in imaging and therapeutic purposes,with a focus on in vivo utilization.展开更多
The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and thei...The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.展开更多
In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential ...In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential function for double square-well(DSW) model,In addition,the equation of second virial coefficient for DSW model is derived from the statistical mechanics method.The above equation obtained has been verified by tests and the test results are excellent.It is concluded that this equation can well represent the behaviour of fluid molecules.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51573107 and 21432005)the Youth Science and Technology Foundation of Sichuan Province(No.2013JQ0032)+2 种基金the Foundation of State Key Laboratory of Polymer Materials Engineering(sklpme2014-3-05)the Synergistic Innovation Joint Foundation of CAEPSCU(No.XTCX2014008)the Fundamental Research Funds for the Central Universities(Nos.2012SCU04B01 and YJ2011025)
文摘A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 mA.cm-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.
基金This work was financially supported by the National Natural Science Foundation of China （Grant No. 61604093）, the Shanghai Pujiang Program （16PJ1403300）, the Natural Science Foundation of Shanghai （16ZR1411000）, the Science and Technology Commission of Shanghai Municipality Program （17DZ2281700）, and the Shanghai Software and integrated circuit industry development special funds （170401）.
文摘Squaraine （SQ） dyes have been considered as efficient photoactive materials for organic solar cells. In this work, we purposely controlled the molecular aggregation of an SQ dye, 2,4-bis[4-（N,N-dibutylamino）-2-dihydroxyphenyl] SQ （DBSQ- （OH）2） in the DBSQ（OH）2：[6,6]-phenyl-Cel-butyric acid methyl ester （PCBM） blend film by using the thermal annealing method, to study the influence of the molecular aggregation on film properties as well as the photovoltaic performance of DBSQ（OH）2：PCBM-based bulk heterojunction （BHJ） solar cells. Our results demonstrate that thermal annealing may change the aggregation behavior of DBSQ（OH）2 in the DBSQ（OH）2：PCBM film, and thus significantly influence the surface morphology, optical and electrical properties of the blend film, as well as the photovoltaic performance of DBSQ（OH）2：PCBM BHJ cells.
基金973 Programme (No. 2011CB932502)NNSFC (Nos. 91227107, 21432004, and 21272125) for financial support
文摘A β cyclodextrin derivative bearing seven cationic arms and its singly charged analogue, i.e., per-6- deoxy-f-（1-methylimidazol-3-ium-3-yl）-β-cyclodextrin （3） and mono-fi-deoxy-6-（1-methylimidazol- 3-ium-3-yl）-β-cyclodextrin （4） were synthesized and fully characterized. Their induced aggregation behaviours towards two anionic surfactant, that is, sodium dodecyl sulfonate （SDS） and dioctyl sodium sulfosuccinate （Aerosol OT, AOT）, were investigated by UV-vis, NMR, Zeta-potential, dynamic light scattering （DLS）, and transmission electron microscopy. The results revealed that host 3 can induce the molecular aggregation of anionic surfactant at concentration far lower than its original CAC, leading to the larger diameter, the narrower size distribution and the higher thermal stability of the induced aggregate towards the anionic surfactant possessing more hydrophobic tails.
基金was supported by the National Natural Science Foundation of China(Grant Nos.61176054 and 61222401)the Natural Science Foundation of Jiangsu Province(No.BK20130311)+1 种基金the Postdoctoral Science Foundation(Grant Nos.2014M550302 and 1302015A)the Collaborative Innovation Center of Suzhou Nano Science and Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A widely-used naphthalenediimide （NDI） based electron acceptor P（NDI2OD-T2） with different number- average molecular weight （Mn） of 38 （N2200L）, 56 （N2200M）, 102 （N2200H） kDa were successfully prepared. The effect of molecular-weight on the performance of all-polymer solar cells based on Poly（5-（5-（4,8- bis（ 5-decylthiophen-2-yl ）-6-methylbenzo[1,2-b： 4,5-b＇]dithophen-2-yl ）thiophen-2-yl ）-6,7-difluoro-8- （5-methylthiophen-2-yl）-2,S-bis（3-（octyloxy）phenyl）quinoxaline） （P2F-DE）：N2200 was systematically investigated. The results reveal that N2200 with increased M. show enhanced intermolecular interac- tions, resulting in improved light absorption and electron mobility. However, the strong aggregation trend of N2200H can cause unfavorable morphology for exciton dissociation and carrier transport. The blend film using N2200 with moderate M. actually develops more ideal phase segregation for efficient charge separation and transport, leading to balanced electron/hole mobility and less carrier recombi- nation. Consequently, all-polymer solar cells employing P2F-DE as the electron donor and N2200M as the electron acceptor show the highest efficiency of 4.81%, outperforming those using N2200L （3,07~;） and N2200H （S,92%）. Thus, the Mn of the polymer acceptor plays an important role in all-polymer solar ceils, which allows it to be an effective parameter for the adjustment of the device morphology and efficiency.
基金financially supported by the Science and Technology Commission of Shanghai Municipality (No.20JC1414900)the National Natural Science Foundation of China (No.52203005)the Science and Technology Commission of Shanghai Municipality (No.21ZR1401400)。
文摘Regioregular poly(3-hexylthio)thiopene(P3HTT) has emerged tremendous potential in organic electronic applications due to the strong noncovalent interactions from the sulfur atom linked to thiophene. However, P3HTT generally exhibits low charge mobility mostly due to poor solution processability attributed to dense arrangement of hexylthio side chain in polymer, which led to strong noncovalent interactions among sulfur atoms. To balance the nonvalent interaction and aggregation for P3HTT, herein, we systematically study the effect of hexylthio side chain content in polymer backbone on the structure and properties. A series of regioregular P3HTT-based homopolymers(P3HTT, P3HTT-50,P3HTT-33 and P3HTT-25) were prepared via Kumada catalyst transfer polycondensation method from a set of mono-, bi-, ter-and quarterthiophenes containing different contents of hexylthio side chain. The DFT calculation shows the planarity of polymers backbone could be improved through reducing the density of hexylthio side chain in polymer mainchain. And significant changes in their crystallinity, aggregation and optical properties were observed with the content of hexylthio side chain reducing. The P3HTT-33 displayed the highest field-effect transistor hole mobility of 2.83×10^(-2) cm^(2)·V^(-1)·s^(-1) resulting from a balance between the crystallinity and planarity. This study demonstrates modulating the content of hexylthio side chain in P3HTT is an effective strategy to optimize the opto-electronic properties of polymer obtaining excellent semiconductor device performance.
基金Supported by the National Natural Science Foundation of China(U22B6004)Scientific Research and Technological Development Project of RIPED(2022yjcq03)Technology Research Project of PetroChina Changqing Oilfield Company(KJZX2023-01)。
文摘Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiments and molecular dynamics numerical simulations were conducted to investigate the effects of changes in shale oil composition on macroscopic fluidity.The concept of“component flow”for shale oil was proposed,and the formation mechanism and conditions of component flow were discussed.The research reveals findings in four aspects.First,a miscible state of light,medium and heavy hydrocarbons form within micropores/nanopores of underground shale according to similarity and intermiscibility principles,which make components with poor fluidity suspended as molecular aggregates in light and medium hydrocarbon solvents,such as heavy hydrocarbons,thereby decreasing shale oil viscosity and enhancing fluidity and outflows.Second,small-molecule aromatic hydrocarbons act as carriers for component flow,and the higher the content of gaseous and light hydrocarbons,the more conducive it is to inhibit the formation of larger aggregates of heavy components such as resin and asphalt,thus increasing their plastic deformation ability and bringing about better component flow efficiency.Third,higher formation temperatures reduce the viscosity of heavy hydrocarbon components,such as wax,thereby improving their fluidity.Fourth,preservation conditions,formation energy,and production system play important roles in controlling the content of light hydrocarbon components,outflow rate,and forming stable“component flow”,which are crucial factors for the optimal compatibility and maximum flow rate of multi-component hydrocarbons in shale oil.The component flow of underground shale oil is significant for improving single-well production and the cumulative ultimate recovery of shale oil.
基金supported by the National Natural Science Foundation of China(51873204 and 51933010)the 111 Project(B21005)+3 种基金the National 1000-talent-plan program(1110010341)the Science and Technology Program of Shaanxi Province(2021KJXX-13)the Fundamental Research Funds for the Central Universities(GK202103104)supported by Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,and Chinese Academy of Sciences.
文摘Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow the mechanical ductility of active layers,the photovoltaic efficiencies usually drops in the resulting OSCs.Herein,a high photovoltaic efficiency of 15.03%and a large crack-onset strain of 15.70%is simultaneously achieved based on a ternary blend consisting of polymer donor poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))](PM6),non-fullerene accepter 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(Y6),and soft elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene(SEBS)through the control of phase separation and crystallization.By employing a high-boiling point solvent additive 1-chloronaphthalene(CN)with different solubilities for PM6 and Y6,the aggregation dynamics of PM6 and Y6 as well as the film solidification process are dramatically altered,allowing for the different molecular rearrangement and liquid-liquid phase separation evolution.Consequently,the ternary film with optimal CN content presents decreased SEBS domains and moderately improved molecular ordering of PM6 and Y6,enabling effective mechanical deformation and charge generation/transport.The revealed corrections between the film-formation process,film microstructure,and photovoltaic/mechanical characteristics in the ternary blend provide deep understanding of the morphology control toward high-performance stretchable OSCs.
基金support from A*STAR under its Advanced Manufacturing and Engineering Program(A2083c0051).
文摘Salt stress remains a significant challenge for crop growth and food security.The development of effective analytical tools for salt stress-related studies is of great importance.Recently,Yang and Yin et al.have developed a novel biosensor that effectively traces salt stress in plants,based on salt-induced molecular J-aggregation and the corresponding changes in fluorescence signals.
基金financially supported by the National Project “Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source"(No. Y31M0112C1)the National Basic Research Program of China(No. 2011CB808402)+1 种基金the National Thousand Youth Talents Program and Young Professionals Program in Institute of Chemistry, Chinese Academy of Sciences(No. Y3297B1261)the National Natural Science Foundation of China(No. 21373165)
文摘We present a study of spectroscopic identification towards the molecular aggregates of zinc tetraphenylporphyrin （ZnTPP） illustrating how the energy states and intermolecular interactions determine the tunable properties of functional materials in condensation processes. Distinguishable fingerprints of ZnTPP nanorods and nanosheets are addressed utilizing X-ray diffraction （XRD）, Raman and UV-vis absorption spectroscopies. Although these ZnTPPs are assigned to J-aggregation at different extent, the spectral analysis reveals a significant role of the intermolecular interactions associated with varying mesoscale architectures. Energy decomposition analysis （EDA） revealed that the varied ZnTPP aggregates are stabilized by altered dispersion interactions due to the dominant ~r...zr stacking between the monomers.
基金Young Top-notch Talents of“High-level Talents Special Support Program”of Shaanxi ProvinceNational Natural Science Foundation of China,Grant/Award Numbers:81971290,82102074。
文摘To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simultaneously.Four-in-one molecular aggregates were prepared to implement this strategy,which comprised of Pro and Eto with the bridging molecule monoglyceride monooleate(GMO)and sur-factant F127 through intermolecular forces.The blood-brain barrier(BBB)targeted lactoferrin(LF)is affixed to their surface,obtaining thefinal molecular aggregates.By employing lactoferrin enrich aggregates to the BBB,followed by ultrasound combine microbubbles to open the BBB,a remarkable 4.5-fold enhancement in brain drug delivery was achieved.The molecular aggregates group maintained sta-ble parameters of heart rate,diastolic blood pressure,and systolic blood pressure.A notable increase of more than twice therapeutic index(TI)value was observed,implying their higher anesthesia efficiency and reduced toxicity.Electroencephalo-gram(EEG)experiments demonstrate a significant elevation in the proportion of θ waves from 28%to 80%for aggregates,accompanied by a nearlyfivefold reduc-tion in the proportion ofθwaves,meaning a significant improvement in synergistic anesthesia effectiveness(interaction index 0.289)with lower drug dosage.Further-more,mouse immunofluorescence brain slice experiments suggest Pro and Eto enter the GABA receptor simultaneously,resulting in synergistic inhibition of GABA receptors.
基金National Key R&D Program of China,Grant/Award Number:2020YFA0715000National Natural Science Foundation of China,Grant/Award Number:51773109。
文摘Intermolecular charge transfer(inter-CT)is commonly considered to quench luminescence in molecular aggregates,especially for near-infrared(NIR)emission.Herein,by elaborate comparison ofπ-bridge effects in donor/acceptor(D/A)molecules,it is disclosed that aπ-bridge is essential in D/A molecule to involve inter-CT in aggregates for inducing desired thermally activated delayed fluorescence(TADF)and largely suppressing non-radiative decays,and importantly,electrondonatingπ-bridge is critical to maximize radiative decay for inter-CT dominated emission by effective electronic coupling with bright intramolecular charge transfer(intra-CT)for high-efficiency NIR emission.As a proof-of-concept,TPATAP with thienyl asπ-bridge realized prominent photoluminescence quantum yields of 18.9%at 788 nm in solid films,and achieved record-high maximum external quantum efficiencies of 4.53%at 785 nm in devices.These findings provide fresh insight into interplay between inter-CT and intra-CT in molecular aggregates and open a new avenue to attenuate the limitation of energy gap law for developing highly efficient NIR emitters and improving the luminescent efficiency of various inter-CT systems,such as organic photovoltaic,organic long persistent luminescence,etc.
基金supported by the National Natural Science Foundation of China(82272145)and the Foundation of Westlake University.
文摘CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes the essential role of noncovalent interactions,particularly in peptide-based materials.Key forces,such as aromatic stacking and hydrogen bonding,are crucial for promoting molecular aggregation and stabilizing supramolecular structures.Numerous studies demonstrate how these interactions influence the phase transitions and the morphology of self-assembled structures.Recent advances in computational methodologies,including molecular dynamics simulations and machine learning,have significantly enhanced our understanding of self-assembly processes.These tools enable researchers to predict how molecular properties,such as hydrophobicity,charge distribution,and aromaticity,affect assembly behavior.Simulations uncover the energetic landscapes governing peptide aggregation,providing insights into the kinetic pathways and thermodynamic stabilities.Meanwhile,machine learning facilitates the rapid screening of peptide libraries,identifying sequences with optimal self-assembly characteristics,and accelerating material design with tailored functionalities.Beyond their structural and physicochemical properties,self-assembled peptide nanostructures hold immense potential in biological applications due to their versatility and biocompatibility.By manipulating molecular interactions,researchers have engineered responsive systems that interact with cellular environments to elicit specific biological responses.These peptide nanostructures can mimic extracellular matrices,facilitating cell adhesion,proliferation,and differentiation.They also show promise in modulating immune responses,recruiting immune cells,and regulating signaling pathways,making them valuable tools in immunotherapy and regenerative medicine.Moreover,their ability to disrupt bacterial membranes positions them as innovative alternatives to conventional antibiotics,addressing the urgent need for solutions to antimicrobial resistance.Despite its promise,peptide self-assembly faces several challenges.The assembly process is highly sensitive to environmental conditions,such as pH,temperature,and ionic strength,leading to variability in the morphology and properties.Furthermore,peptide aggregation can result in heterogeneous and poorly defined assemblies,complicating the reproducibility and scalability.Designing peptides with predictable self-assembly behavior remains a significant hurdle.Looking ahead,integrating computational predictions with experimental validations will be crucial in discovering novel peptide sequences with tailored self-assembly properties.Machine learning,combined with high-throughput screening techniques,will enable the rapid identification of optimal peptide sequences.In situ characterization tools,such as cryoelectron microscopy and advanced spectroscopy,will provide deeper insights into assembly mechanisms,aiding the rational design of peptide materials.As research progresses,the dynamic and reversible nature of noncovalent interactions can be leveraged to create adaptive responsive to environmental stimuli.Self-assembled peptide nanostructures are poised for impactful applications in biomedicine including targeted drug delivery,tissue repair,and advanced therapeutic strategies.Ultimately,these nanostructures represent a powerful platform for addressing complex challenges in biomedicine and beyond,paving the way for transformative breakthroughs in science and technology.
基金supported by the Deutsche Forschungsgemeinschaft(DFG,RTG-2591,and Template-designed Organic Electronics-TIDE)Linz Institute of Technology(LIT-2019-7-INC-313 SEAMBIOF,LI1013770001-2D3M).
文摘While chirality is a prevalent character of numerous biological and synthetic organic molecules,its selective absorption of circularly polarized light,known as circular dichroism(CD),is typically small due to intrinsically weak coupling between magnetic and electric dipoles.However,thin films of aggregated,enantiopure prolinol-derived squaraine molecules(ProSQ-C16)exhibit an unusually large excitonic CD signal,although the underlying mechanism is not yet known.In this study,we employ steady-state and ultrafast transient absorption spectroscopy to investigate the nature and dynamics of excitons in aggregates of enantiopure and racemic ProSQ-C16 thin films.Highly resembling transient responses of enantiopure thin films under excitations at different photon energies strongly indicate that a single type of aggregate dominates the linear optical response,that is,a strong red-shifted(J-like)and weak blue-shifted(H-like)absorption band.On the other hand,the transient properties of the racemic thin film deviate from this pattern and remain largely ambiguous.The short lifetime of excited states and coherent oscillations present in the dynamics of the transient absorption signal indicate that the early time dynamics are governed by a transition towards a dark intermediate state,which might arise from intermolecular charge transfer with potential contributions from the coupling of excitons to the vibrations.This non-radiative relaxation pathway explains the unusually weak fluorescence of the predominately J-like behaving aggregate.Our findings conclusively show that the chiral aggregate structure has a strong impact on the optical and dynamic response of the excitons and underline the significance of non-Frenkel exciton states for the optical properties of anilino squaraine dyes.
基金the National Natural Science Foundation of China (21290190)
文摘We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on theoretical investigation of the electronic structures and dynamic processes upon photo-and electric-excitation for molecules and aggregates. We aim to develop reliable methodology to predict the optoelectronic properties of molecular materials related to the electronic excitations and to apply in the experiments. We identify two essential scientific challenges: (i) nature of intramolecular and intermolecular electronic excited states; (ii) theoretical description of the dynamic processes of the coupled motion of electronic excitations and nucleus. We propose the following four subjects of research: (i) linear scaling time-dependent density-functional theory and its application to open shell system; (ii) computational method development of electronic excited state for molecular aggregates; (iii) theoretical investigation of the time evolution of the excited state dynamics; (iv) methods to predict the optoelectronic properties starting from electronic excited state investigation for organic materials and experimental verifications.
基金the National Natrual Science Foundation of China (21290193)
文摘This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodology development is especially based on the time-dependent density functional theory (TDDFT) and valence bond (VB) theory, and is expected to be computationally effective and accurate as well. Research works on the following related subjects will be performed: (1) The analytical energy-derivative approaches for electronically excited state within TDDFT will be developed to reduce bypass the computational costs in the calculation of molecular excited-state properties. (2) The ab initio methods for electronically excited state based on VB theory and hybrid TDDFT-VB method will be developed to overcome the limitations of current TDDFT in simulating photophysics and photochemistry. (3) For larger aggregates, neither ab initio methods nor TDDFT is applicable. We intend to build the effective model Hamiltonian by developing novel theoretical and computational methods to calculate the involved microscopic physical parameters from the first-principles methods. The constructed effective Hamiltonian is then used to describe the excitonic states and excitonic dynamics of the natural or artificial photosynthesized systems, organic or inorganic photovoltaic cell. (4) The condensed phase environment is taken into account by combining the developed theories and algorithms based on TDDFT and VB with the polarizable continuum solvent models (PCM), molecular mechanism (MM), classical electrodynamics (ED) or molecular dynamics (MD) theory. (5) Highly efficient software packages will be designed and developed.
基金the National Natural Science Foundation of China(51773109,21788102)National Key R&D Program of China(2020YFA0715001,2017YFA0204501)+1 种基金National Postdoctoral Program for Innovative Talents(BX20180159)the Project funded by China Postdoctoral Science Foundation(2019M660606)。
文摘Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to decelerate k_(nr) are mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small k_(nr) for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.
基金the National Natural Science Foundation of China (21290194)
文摘This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". This study will focus on developments of novel methods to simulate excited state dynamics of molecular aggregates, with the aim of understanding several important chemical physics processes, and providing a solid foundation for predicting the opto-electronic properties of organic functional materials and devices. The contents of this study include: (1) The quantum chemical methods for electronic excited state and electronic couplings targeted for dynamics in molecular aggregates; (2) Methods to construct effective Hamiltonian models, and to solve their dynamics using system-bath approaches; (3) Non-adiabatic mixed quantum-classic methods targeted for molecular aggregates; (4) Theoretical studies of charge and energy transfer, and related spectroscopic phenomena in molecular aggregates.
基金Korea Institute of Science and Technology,Grant/Award Number:2E31093Korea University,Grant/Award Number:K2110571National Research Foundation of Korea,Grant/Award Numbers:2017M3A9D8029942,2018M3A9H4079286,2019M3D1A1078941,2019R1A6A1A11051471,2020R1A2C2004422,2020R1C1C1010044,2021R1A2C2005418。
文摘Molecular aggregates are receiving tremendous attention,demonstrating immense potential for biomedical applications in vitro and in vivo.For instance,the molecular aggregates of conventional fluorophores influence the electronic excitation states of the aggregates,causing characteristic photophysical property changes.A fundamental understanding of this classical relationship between molecular aggregate structures and photophysics has allowed for innovative biological applications.The chemical characteristics of drug molecules generally trigger the formation of colloidal aggregates,and this is considered detrimental to the drug discovery process.Furthermore,nano-sized supramolecular aggregates have been used in biomedical imaging and therapy owing to their optimal properties for in vivo utility,including enhanced cell permeability,passive tumor targeting,and convenient surface engineering.Herein,we provide an overview of the recent trends in molecular aggregates for biomedical applications.The changes in photophysical properties of conventional fluorophores and their biological applications are discussed,followed by the effects of conventional drug molecule-aggregates on drug discovery and therapeutics development.Recent trends in the investigation of biologically important analytes with aggregation-induced emission are discussed for conventional and unconventional fluorophores.Lastly,we discuss nano-sized supramolecular aggregates used in imaging and therapeutic purposes,with a focus on in vivo utilization.
文摘The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.
文摘In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential function for double square-well(DSW) model,In addition,the equation of second virial coefficient for DSW model is derived from the statistical mechanics method.The above equation obtained has been verified by tests and the test results are excellent.It is concluded that this equation can well represent the behaviour of fluid molecules.
