Nonadiabatic dynamics of electron injection into organic molecules

We numerically investigate the injection process of electrons from metal electrodes to one-dimensional organic molecules by combining the extended Su Schrieffer Heeger （SSH） model with a nonadiabatic dynamics method. It is found that a match between the Fermi level of electrodes and the highest occupied molecular orbital （HOMO） or the lowest unoccupied molecular orbital （LUMO） of organic molecules can be greatly affected by the length of the organic chains, which has a great impact on electron injection. The correlation between oligomers and electrodes is found to open more efficient channels for electron injection as compared with that in polymer/electrode structures. For oligomer/electrode structures, we show that the Schottky barrier essentially does not affect the electron injection as the electrode work function is smaller than a critical value work-function electrode. For polymer/electrode structures This means that the Schottky barrier is pinned for a small we find that it is possible for the Fermi level of electrodes to be pinned to the polaronic level. The condition under which the Fermi level of electrodes exceeds the polaronic level of polymers is shown to not always lead to spontneous electron transfer from electrodes to polymers.

Interaction Energy Prediction of Organic Molecules using Deep Tensor Neural Network

The interaction energy of two molecules system plays a critical role in analyzing the interacting effect in molecular dynamic simulation.Since the limitation of quantum mechanics calculating resources,the interaction energy based on quantum mechanics can not be merged into molecular dynamic simulation for a long time scale.A deep learning framework,deep tensor neural network,is applied to predict the interaction energy of three organic related systems within the quantum mechanics level of accuracy.The geometric structure and atomic types of molecular conformation,as the data descriptors,are applied as the network inputs to predict the interaction energy in the system.The neural network is trained with the hierarchically generated conformations data set.The complex tensor hidden layers are simplified and trained in the optimization process.The predicted results of different molecular sys tems indica te that deep t ensor neural net work is capable to predic t the interaction energy with 1 kcal/mol of the mean absolute error in a relatively short time.The prediction highly improves the efficiency of interaction energy calculation.The whole proposed framework provides new insights to introducing deep learning technology into the interaction energy calculation.

Nonadiabatic dynamics of electron injection into organic molecules

We numerically investigate the injection process of electrons from metal electrodes to one-dimensional organic molecules by combining the extended Su–Schrieffer–Heeger (SSH) model with a nonadiabatic dynamics method. It is found that a match between the Fermi level of electrodes and the highest occupied molecular orbital (HOMO) or the lowest unoccupied molecular orbital (LUMO) of organic molecules can be greatly affected by the length of the organic chains, which has a great impact on electron injection. The correlation between oligomers and electrodes is found to open more efficient channels for electron injection as compared with that in polymer/electrode structures. For oligomer/electrode structures, we show that the Schottky barrier essentially does not affect the electron injection as the electrode work function is smaller than a critical value. This means that the Schottky barrier is pinned for a small work-function electrode. For polymer/electrode structures, we find that it is possible for the Fermi level of electrodes to be pinned to the polaronic level. The condition under which the Fermi level of electrodes exceeds the polaronic level of polymers is shown to not always lead to spontaneous electron transfer from electrodes to polymers.

Surface chemical microenvironment engineering of catalysts by organic molecules for boosting electrocatalytic reaction

Electrocatalysis is a surface-sensitive process,in which the catalytic activity of electrocatalyst highly re-lates to the surface adsorption/desorption behaviors of the reactants/intermediates/products on the cat-alytically active sites.Surface chemical microenvironment engineering via organic molecules functional-ization is a promising strategy to tune the electrocatalytic activity since it can well modify the elec-trode/electrolyte interface and alter the reaction pathways.In this review,we summarize the recent progress of surface microenvironment engineering of electrocatalysts induced by organic molecules func-tionalization,with the special focus on the organic molecule-assisted growth mechanism and unique electronic effect.More importantly,the applications of organic molecule functionalized catalysts in var-ious electrocatalytic reactions are also systematically summarized,along with a deep discussion on the conclusion and perspective.This work will open a new avenue for the construction and modification of advanced electrocatalysts based on organic molecule-mediated interface engineering.

Building the bridge of small organic molecules to porous carbons via ionic solid principle

Replacing traditional polymer-based precursors with small molecules is a promising pathway toward facile and controllable preparation of porous carbons but remains a prohibitive challenge because of the high volatility of small molecules.Herein,a simple,general,and controllable method is reported to prepare porous carbons by converting small organic molecules into organic molecular salts followed by pyrolysis.The robust electrostatic force holding organic molecular salts together leads to negligible volatility and thus ensures the formation of carbons under high-temperature pyrolysis.Meanwhile,metal moieties in organic molecular salts can be evolved into in-situ templates or activators during pyrolysis to create nanopores.The modular nature of organic molecular salts allows easy control of the porosity and chemical doping of carbons at a molecular level.The sulfur-doped carbon prepared by the ionic solid strategy can serve as robust support to prepare small-sized intermetallic PtCo catalysts,which exhibit a high mass activity of 1.62 A·mgPt^(−1)in catalyzing oxygen reduction reaction for fuel cell applications.

Implications of electrode modifications in aqueous organic redox flow batteries

Aqueous organic redox flow batteries(RFBs)exhibit favorable characteristics,such as tunability,multielectron transfer capability,and stability of the redox active molecules utilized as anolytes and catholytes,making them very viable contenders for large-scale grid storage applications.Considerable attention has been paid on the development of efficient redox-active molecules and their performance optimization through chemical substitutions at various places on the backbone as part of the pursuit for high-performance RFBs.Despite the fact that electrodes are vital to optimal performance,they have not garnered significant attention.Limited research has been conducted on the effects of electrode modifications to improve the performance of RFBs.The primary emphasis has been given on the impact of electrode engineering to augment the efficiency of aqueous organic RFBs.An overview of electron transfer at the electrode-electrolyte interface is provided.The implications of electrode modification on the performance of redox flow batteries,with a particular focus on the anodic and cathodic half-cells separately,are then discussed.In each section,significant discrepancies surrounding the effects of electrode engineering are thoroughly examined and discussed.Finally,we have presented a comprehensive assessment along with our perspectives on the future trajectory.

Design strategy and bioimaging of small organic molecule multicolor fluorescent probes

Multicolor fluorescent probes based on small organic molecules have the advantages of low cost, good biocompatibility, easily modifiable molecular structures and adjustable fluorescence performance. In addition, small molecule multicolor fluorescent probes generally undergo multi-site or multi-step reactions, which means that they can be used for the specific detection of structurally similar substances in complex bio-systems. In this review, we focus on the design and application of multicolor fluorescent probes based on small organic molecules: single fluorophores with multiple reaction sites, multiple fluorophores with single reaction sites, or multiple fluorophores with multiple reaction sites. Moreover, a design strategy for multicolor fluorescent probes and its application in biological imaging are also summarized, providing a systematic plan for future research on fluorescent probes functionalized by small organic molecules. It will also play an important role in the development of additional functions for small organic molecule fluorescent probes.

Recent progress on the excited-state multiple proton transfer process in organic molecules

In contrast to the widely reported excited-state single proton-transfer,excited-state multiple proton transfer(ESMPT)containing two or more intra-or inter-molecular proton transfers has greatly expanded the research scope of the excited-state proton transfers.In recent decades,ESMPT-active organic molecules have attracted much attention owing to their unique photophysical properties,such as large magnitude Stokes shifts and dual emission.These photophysical properties facilitate the application of the organic molecules in organic solid-state lasers,fluorescent probes and sensors,and molecular switches.Herein,we introduce the fundamentals of the ESMPT and review the recent advances in different types of ESMPTs in organic molecules.Finally,we present our conclusions and the future development prospects of the ESMPT in organic molecules.

Recent advances in nature-inspired nanocatalytic reduction of organic molecules with water

Nature has provided us the assurance and inspiration for thousands of years in synthesizing value-added chemicals,with the assistance of reactive hydrogen species,and water as the ultimate hydrogen source.However,the natural photosynthesis is inefficient due to some intrinsic properties,urging people not only to learn from but also surpass during nature imitation.In this review,we summarized recent progresses on reactive hydrogen species-assisted nanocatalytic reduction of organic molecules towards value-added fine chemicals and pharmaceuticals,with water as the hydrogen source,and especially highlighted how photocatalytically or electrocatalytically evolved reactive hydrogen species synergize with biocatalytic centers and nanocatalytic sites for reduction of organic molecules.The design principles of collaborative semi-artificial systems and nanocatalytic artificial systems,the structure tuning of catalysts for the evolution and utilization of hydrogen species,and the determination of reactive hydrogen species for mechanistic insights were discussed in detail.Finally,perspectives were provided for further advancing this emerging area of nanocatalytic reduction of organic molecules from water(or proton)and organics.

Photovoltaic molecules based on vinylene-bridged oligothiophene applied for bulk-heterojunction organic solar cells

We have synthesized two photovoltaic molecules（HEX-3TVT-ID and EH-3TVT-ID） based on vinylenebridged oligothiophene applied as donor for the solution-processable bulk-heterojunction organic solar cells（OSCs）. Vinylene unit was introduced as π-bridge in the oligothiophenes with 1,3-indenedione as end group and 4,4’-dihexyl-2,2’：5’,2’-terthiophene or 3’,4’-di（octan-3-yl）-2,2’：5’,2’-terthiophene as core,respectively. Due to the different substituent positions of the alkyl group relative to the vinylene unit in the terthiophene, HEX-3TVT-ID and EH-3TVT-ID show different optical and electrochemical properties, corresponding to the photovoltaic performance of the OSCs devices. The power conversion efficiency（PCE） of the OSCs based on a blend of HEX-3TVT-ID and PC71BM（1：0.8, weight ratio, 0.5% CN） reached 2.3%. In comparison, the OSCs based on the blend of EH-3TVT-ID and PC71BM in the weight ratio of 1：1 without the additive show a higher PCE of 2.7%, with a typically high VOC of 0.93 V, under the illumination of AM 1.5, 100 mW cm-2.

The reaction of perfluoroalkanesulfonyl halides Ⅷ. A mild method for introducing BrCF_2 group to organic molecules

BrCF_2SO_2Br, prepared from sulfinatodehalogenation of CF_2Br_2 followed by bromination of the intermediate BrCF_2SO_2Na, was shown to be a mild and efficient bromodifluoromethylating agent.

Widespread complex organic molecules in the Galactic center

With the support by the Major Program of the National Natural Science Foundation of China,a research group led by Prof.Shen Zhiqiang（沈志强）from Shanghai Astronomical Observatory,Chinese Academy of Sciences reports the detection of widespread CH2OHCHO（glycolaldehyde） and

14.46% Efficiency small molecule organic photovoltaics enabled by the well trade-off between phase separation and photon harvesting

Small molecule organic photovoltaics(SMPVs) were prepared by utilizing liquid crystalline donor material BTR-Cl and two similar optical bandgap non-fullerene acceptor materials BTP-BO-4 F and Y6.The BTPBO-4 F and Y6 have the similar optical bandgap and different absorption coefficients.The corresponding binary SMPVs exhibit different short circuit current density(/sc)(20.38 vs.23.24 mA cm^(-2)),and fill factor(FF)(70.77% vs.67.21%).A 14.46% power conversion efficiency(PCE) is acquired in ternary SMPVs with 30 wt% Y6,companied with a JSC of 24.17 mA cm^(-2) a FF of 68.78% and an open circuit voltage(Voc) of 0.87 V.The improvement on PCE of ternary SMPVs should originate from the well trade-off between phase separation and photon harvesting of ternary active layers by incorporating 30 wt% Y6 in acceptors.This work may deliver insight onto the improved performance of SMPVs by superposing the superiorities of binary SMPVs with similar optical bandgap acceptors into one ternary cell.

Kinetic and thermodynamic synergy of organic small molecular additives enables constructed stable zinc anode

An organic small molecule additive zinc formate is introduced to construct stable Zn metal interphase by electrochemical kinetic control and thermodynamic adjustment.It partially forms a water-formate concomitant dipole layer at the internal Helmholtz electrical double layers(HEDLs) under the preferential adsorption function of formate on Zn surface,reducing the occurrence of side reactions at phase interface.Meanwhile,free formate in HEDLs regulates the Zn^(2+) solvation sheath structure to accelerate the desolvation,transference,and deposition kinetics of Zn^(2+).Besides,the hydrolysis reaction of zinc formate increases the hydrogen evolution overpotential,inhibiting the thermodynamic tendency of hydrogen evolution.Consequently,it presents stable cycle for more than 2400 h at 5 mA cm^(-2),as well as an average Coulombic efficiency of 99.8% at 1 A g^(-1) after 800 cycles in the Zn‖VO_(2) full cell.The interphase engineering strategy zinc anode by organic small molecular brings new possibility towards high-performance aqueous zinc-ion batteries.

Construction of the Plasmid Reference Molecule for Detection of Transgenic Soybean MON89788

[Objective] The aim was to construct a plasmid reference molecule (PRM) for detection of transgenic soybean MON89788. [Method] the lectin gene sequence,3'-junction and 5'-junction sequence between host plant DNA integrated DNA of MON89788 soybean were amplified independently,and the three fragments were cloned into the cloning vector pMD18-T in order through molecular manipulation method to construct pMD-LM3M5,the applicability of the constructed novel PRM was tested. [Result] Sequencing confirmation result showed that the PRM was 3 700 bp in length,containing 1 029 bp of recombined DNA fragment. The limits of qualitative detection of the PRM were 10 copies. [Conclusion] The PRM constructed in this study was suitable for the identification of MON89788 event.

A universal strategy of multi-objective active learning to accelerate the discovery of organic electrode molecules

Organic electrode molecules hold significant potential as the next generation of cathode materials for Li-ion batteries. In this study, we have introduced a multi-objective active learning framework that leverages Bayesian optimization and non-dominated sorting genetic algorithms-Ⅱ. This framework enables the selection of organic molecules characterized by high theoretical energy density and low gap(LUMO-HOMO)(LUMO, lowest unoccupied molecular orbital;HOMO, highest occupied molecular orbital). Remarkably, after only two cycles of active learning, the determination of coefficient can reach 0.962 for theoretical energy density and 0.920 for the gap with a modest dataset of 300 molecules, showcasing superior predictive capabilities. The 2,3,5,6-tetrafluorocyclohexa-2,5-diene-1,4-dione, selected by non-dominated sorting genetic algorithms-Ⅱ, has been successfully applied to Li-ion batteries as cathode materials, demonstrating a high capacity of 288 m Ah g^(-1)and a long cycle life of 1,000 cycles. This outcome underscores the high reliability of our framework. Furthermore, we have also validated the universality and transferability of our framework by applying it to two additional databases, the QM9 and OMEAD. When the training dataset of the model includes at least 500 molecules, the determination of coefficient essentially reaches approximately0.900 for four targets: gap, reduction potential, LUMO, and HOMO. Therefore, the universal framework in our work provides innovative insights applicable to other domains to expedite the screening process for target materials.

Two-photon absorption properties of aggregation systems on the basis of (E)-4-(2-nitrovinyl) benzenamine molecules

Aggregation effect caused by the intermolecular hydrogen-bonding interactions on two-photon absorption prop- erties of （E）-4-（2-nitrovinyl） benzenamine molecules is studied at a hybrid density functional level. The geometry optimization studies indicate that there exist two probable conformations for the dimers and three for the trimers. A strong red-shift of the charge-transfer states is shown. The two-photon absorption cross sections of the molecule for certain conformations are greatly enhanced by the aggregation effect, from which a ratio of 1.0：2.6：3.6 is found for the molecule and its dimer and trimer with nearly planar structures. Namely, a 30 or 20 percent increase of the two-photon absorption cross section is observed.

Atomic force microscopy investigation of growth process of organic TCNQ aggregates on SiO_2 and mica substrates

Deposition patterns of tetracyanoquinodimethane （TCNQ） molecules on different surfaces are investigated by atomic force microscopy. A homemade physical vapour deposition system allows the better control of molecule deposition. Taking advantage of this system, we investigate TCNQ thin film growth on both SiO2 and mica surfaces. It is found that dense island patterns form at a high deposition rate, and a unique seahorse-like pattern forms at a low deposition rate. Growth patterns on different substrates suggest that the fractal pattern formation is dominated by molecule-molecule interaction. Finally, a phenomenal ＂two-branch＂ model is proposed to simulate the growth process of the seahorse pattern.

Opportunities and challenges of organic flow battery for electrochemical energy storage technology

For flow batteries(FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs(OFBs) which employ organic molecules as redox-active materials have been considered as one of the promising technologies for achieving lowcost and high-performance. Herein, we present a critical overview of the progress on the OFBs, including the design principles of key components(redox-active molecules, membranes, and electrodes) and the latest achievement in both aqueous and nonaqueous systems. Finally, future directions in explorations of the high-performance OFB for electrochemical energy storage are also highlighted.

Effect of additives on the photovoltaic properties of organic solar cells based on triphenylamine-containing amorphous molecules

Photovoltaic performance of the organic solar cells （OSCs） based on 2-（（5＇-（4-（（4-（（E）-2-（5＇-（2,2-dicyanovinyl）-3＇,4-dihexyl- 2,2＇-bithiophen-5-yl）vinyl） phenyl）（phenyl）amino）styryl）-4~4＇-dihexyl-2,2＇-bithiophen-5-yl）methylene）malononitrile （L（TPA- bTV-DCN）） as donor and PC70BM as acceptor was optimized using 0.25 vol% high boiling point solvent additive of 1-chloronaphthalene （CN）, 1,6-hexanedithiol （HDT）, or 1,8-diodooctane （DIO）. The optimized OSC based on L（TPA-bTV- DCN）-PC70BM （1：2, w/w） with 0.25 vol% CN exhibits an enhanced power conversion efficiency （PCE） of 2.61%, with Voc of 0.87 V, Jsc of 6.95 mA/cm2, and FF of 43.2%, under the illumination of 100 mW/cm2 AM 1.5 G simulated solar light, whereas the PCE of the OSC based on the same active layer without additive is only 1.79%. The effect of the additive on absorption spectra and the atomic force microscopy images of L（TPA-bTV-DCN）-PCv0BM blend films were further investigated. The improved efficiency of the device could be ascribed to the enhanced absorption and optimized domain size in the L（TPA-bTV-DCN）-PC70BM blend film.