Search

Designing new acceptors is critical for intrinsically stretchable organic solar cells (IS‐OSCs) with high efficiency and mechanical robustness. However, nearly all stretchable polymer acceptors exhibit limited efficiency and high‐performance small molecular acceptors are very brittle. In this regard, we select thienylene‐alkane‐thienylene (TAT) as the conjugate‐break linker and synthesize four dimerized acceptors by the regulation of connecting sites and halogen substitutions. It is found that the connecting sites and halogen substitutions considerably impact the overall electronic structures, aggregation behaviors, and charge transport properties. Benefiting from the optimization of the molecular structure, the dimerized acceptor exhibits rational phase separation within the blend films, which significantly facilitates exciton dissociation while effectively suppressing charge recombination processes. Consequently, FDY‐m‐TAT‐based rigid OSCs render the highest power conversion efficiency (PCE) of 18.07 % among reported acceptors containing conjugate‐break linker. Most importantly, FDY‐m‐TAT‐based IS‐OSCs achieve high PCE (14.29 %) and remarkable stretchability (crack‐onset strain [COS]=18.23 %), significantly surpassing Y6‐based counterpart (PCE=12.80 % and COS=8.50 %). To sum up, these findings demonstrate that dimerized acceptors containing conjugate‐break linkers have immense potential in developing highly efficient and mechanically robust OSCs. [ABSTRACT FROM AUTHOR]

The preparation of formic acid by direct reduction of carbon dioxide is an important basis for the future chemical industry and is of great significance. Due to the serious shortage of highly active and selective electrocatalysts leading to the development of direct reduction of carbon dioxide is limited. Herein the target catalysts with high CO2RR activity and selectivity were identified by integrating DFT calculations and high‐throughput screening and by using graphdiyne (GDY) supported metal oxides quantum dots (QDs) as the ideal model. It is theoretically predicted that GDY supported indium oxide QDs (i.e. InOx/GDY) is a new heterostructure electrocatalyst candidate with optimal CO2RR performance. The interfacial electronic strong interactions effectively regulate the surface charge distribution of QDs and affect the adsorption/desorption behavior of HCOO* intermediate during CO2RR to achieve highly efficient CO2 conversion. Based on the predicted composition and structure, we synthesized the advanced catalytic system, and demonstrates superior CO2‐to‐HCOOH conversion performance. The study presents an effective strategy for rational design of highly efficient heterostructure electrocatalysts to promote green chemical production. [ABSTRACT FROM AUTHOR]

Conjugated coordination polymers (c‐CPs) are unique organic–inorganic hybrid semiconductors with intrinsically high electrical conductivity and excellent charge carrier mobility. However, it remains a challenge in tailoring electronic structures, due to the lack of clear guidelines. Here, we develop a strategy wherein controlling the redox state of hydroquinone/benzoquinone (HQ/BQ) ligands allows for the modulation of the electronic structure of c‐CPs while maintaining the structural topology. The redox‐state control is achieved by reacting the ligand TTHQ (TTHQ=1,2,4,5‐tetrathiolhydroquinone) with silver acetate and silver nitrate, yielding Ag4TTHQ and Ag4TTBQ (TTBQ=1,2,4,5‐tetrathiolbenzoquinone), respectively. In spite of sharing the same topology consisting of a two‐dimensional Ag−S network and HQ/BQ layer, they exhibit different band gaps (1.5 eV for Ag4TTHQ and 0.5 eV for Ag4TTBQ) and conductivities (0.4 S/cm for Ag4TTHQ and 10 S/cm for Ag4TTBQ). DFT calculations reveal that these differences arise from the ligand oxidation state inhibiting energy band formation near the Fermi level in Ag4TTHQ. Consequently, Ag4TTHQ displays a high Seebeck coefficient of 330 μV/K and a power factor of 10 μW/m ⋅ K2, surpassing Ag4TTBQ and the other reported silver‐based c‐CPs. Furthermore, terahertz spectroscopy demonstrates high charge mobilities exceeding 130 cm2/V ⋅ s in both Ag4TTHQ and Ag4TTBQ. [ABSTRACT FROM AUTHOR]

Modulating the electronic structure of electrode materials at atomic level is the key to controlling electrodes with outstanding rate capability. On the basis of modulating the iron cationic vacancies (IV) and electronic structure of materials, we proposed the method of preparing graphdiyne/ferroferric oxide heterostructure (IV‐GDY‐FO) as anode materials. The goal is to motivate lithium‐ion batteries (LIBs) toward ultra‐high capacity, superior cyclic stability, and excellent rate performance. The graphdiyne is used as carriers to disperse Fe3O4 uniformly without agglomeration and induce high valence of Fe with reducing the energy in the system. The presence of Fe vacancy could regulate the charge distribution around vacancies and adjacent atoms, leading to facilitate electronic transportation, enlarge the lithium‐ion diffusion, and decrease Li+ diffusion barriers, and thus displaying significant pseudocapacitive process and advantageous lithium‐ion storage. The optimized electrode IV‐GDY‐FO reveals a capacity of 2084.1 mAh g−1 at 0.1 C, superior cycle stability and rate performance with a high specific capacity of 1057.4 mAh g−1 even at 10 C. [ABSTRACT FROM AUTHOR]

A multi‐level architecture formed alternatively by the conformal graphdiyne (GDY) and CuS is well engineered for Li‐free cathode. Such a proof‐of‐concept architecture efficiently integrates the advantages of GDY and produces new functional heterojunctions (sp−C−S−Cu hybridization bond). The layer‐by‐layer 2D confinement effect successfully avoids structural collapse, the selective transport inhibits the shuttling of active components, and the interfacial sp−C−S−Cu hybridization bond significantly regulates the phase conversion reaction. Such new sp−C−S−Cu hybridization of GDY greatly improves the reaction dynamics and reversibility, and the cathode delivers an energy density of 934 Wh kg−1 and an unattenuated lifespan of 3000 cycles at 1 C. Our results indicate that the GDY‐based interface strategy will greatly promote the efficient utilization of the conversion‐type cathodes. [ABSTRACT FROM AUTHOR]

NIR‐II‐emitting photosensitizers (PSs) have attracted great research interest due to their promising clinical applications in imaging‐guided photodynamic therapy (PDT). However, it is still challenging to realize highly efficient PDT on NIR‐II PSs. In this work, we develop a chlorination‐mediated π–π organizing strategy to improve the PDT of a PS with conjugation‐extended A‐D‐A architecture. The significant dipole moment of the carbon‐chlorine bond and the strong intermolecular interactions of chlorine atoms bring on compact π–π stacking in the chlorine‐substituted PS, which facilitates energy/charge transfer and promotes the photochemical reactions of PDT. Consequently, the resultant NIR‐II emitting PS exhibits a leading PDT performance with a yield of reactive oxygen species higher than that of previously reported long‐wavelength PSs. These findings will enlighten the future design of NIR‐II emitting PSs with enhanced PDT efficiency. [ABSTRACT FROM AUTHOR]

The development of conjugated polymers with high semiconducting performance and high reliability is of great significance for flexible electronics. Herein, we developed a new type of electron‐accepting building block; i.e. non‐symmetric half‐fused B←N coordinated diketopyrrolopyrrole (DPP) (HBNDPP), for amorphous conjugated polymers toward flexible electronics. The rigid B←N fusion part of HBNDPP endows the resulting polymers with decent electron transport, while its non‐symmetric structure causes the polymer to exhibit multiple conformation isomers with flat torsional potential energies. Thus, it gets packed in an amorphous manner in solid state, ensuring good resistance to bending strain. Combined with hardness and softness, the flexible organic field‐effect transistor devices exhibit n‐type charge properties with decent mobility, good bending resistance, and good ambient stability. The preliminary study makes this building block a potential candidate for future design of conjugated materials for flexible electronic devices. [ABSTRACT FROM AUTHOR]

Creating new electron‐deficient unit is highly demanded to develop high‐performance polymer donors for non‐fullerene organic solar cells (OSCs). Herein, we reported a multifluorinated unit 4,5,6,7‐tetrafluoronaphtho[2,1‐b : 3,4‐b′]dithio‐phene (FNT) and its polymers PFNT‐F and PFNT‐Cl. The advantages of multifluorination: (1) it enables the polymers to exhibit low‐lying HOMO (≈−5.5 eV) and wide band gap (≈2.0 eV); (2) the short interactions (F⋅⋅⋅H, F⋅⋅⋅F) endow the polymers with properties of high film crystallinity and efficient hole transport; (3) well miscibility with NFAs that leads to a more well‐defined nanofibrous morphology and face‐on orientation in the blend films. Therefore, the PFNT‐F/Cl : N3 based OSCs exhibit impressive FF values of 0.80, and remarkable PCEs of 17.53 % and 18.10 %, which make them ranked the best donor materials in OSCs. This work offers new insights into the rational design of high‐performance polymers by multifluorination strategy. [ABSTRACT FROM AUTHOR]

Herein, we leverage the Ni‐catalyzed enantioselective reductive dicarbofunctionalization of internal alkenes with alkyl iodides to enable the synthesis of chiral pyrrolidinones bearing vicinal stereogenic centers. The application of newly developed 1‐NapQuinim is critical for formation of two contiguous stereocenters in high yield, enantioselectivity, and diastereoselectivity. This catalytic system also improves both the yield and enantioselectivity in the synthesis of α,α‐dialkylated γ‐lactams. Computational studies reveal that the enantiodetermining step proceeds with a carbamoyl‐NiI intermediate that is reduced by the Mn reductant prior to intramolecular migratory insertion. The presence of the t‐butyl group of the Quinim ligand leads to an unfavorable distortion of the substrate in the TS that leads to the minor enantiomer. Calculations also support an improvement in enantioselectivity with 1‐NapQuinim compared to p‐tolQuinim. [ABSTRACT FROM AUTHOR]

Owing to unique alkyne‐rich structure, graphdiyne (GDY) has been proven to be a superb support for anchoring metal catalysts. Herein we demonstrate a new role of GDY as the wettability modifier for enhanced hydrogenation catalysis. After loading a certain amount GDY nanospheres, the silica mesoporous channels become superaerophilic, which allows gaseous H2 to be directly stored inside, thus significantly increasing the H2 concentration around the palladium nanoparticles (NPs). At the same time, GDY nanospheres also alter the electronic structure of the Pd NPs via a strong d‐π interaction. Combining these two roles of GDY, allows the hydrogenation of benzaldehyde to proceed under ambient H2 pressure in water, with an impressive 4.3‐fold enhancement compared to the unmodified Pd/mSiO2 catalyst. This study demonstrates a new role of GDY in constructing wettability matched catalysts for gas‐liquid‐solid tri‐phase reactions. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are gaining increasing attention as renewable cathode materials for Li‐ion batteries. However, COF electrodes reported so far still exhibit unsatisfying capacity due to their limited active site density and insufficient utilization. Herein, a new two‐dimensional polyimide‐linked COF, HATN‐AQ‐COF with multiple redox‐active sites for storing Li+ ions, was designed and fabricated from a new module of 2,3,8,9,14,15‐hexacarboxyl hexaazatrinaphthalene trianhydrides with a 2,6‐diaminoanthraquinone linker. HATN‐AQ‐COF possessing excellent stability, good conductivity, and a large pore size of 3.8 nm enables the stable and fast ion transport. This, in combination with the abundant redox active sites, results in a high reversible capacity of 319 mAh g−1 at 0.5 C (1 C=358 mA g−1) for the HATN‐AQ‐COF electrode with a high active site utilization of 89 % and good cycle performance, representing one of the best performances among the reported COF electrodes. [ABSTRACT FROM AUTHOR]

Classical psychedelics are a group of hallucinogens which trigger non‐ordinary states of consciousness through activation of the 5‐HT2A receptor (5‐HT2AR) in the brain. However, the exact mechanism of how 5‐HT2AR agonism alters perception remains elusive. When studying receptor signaling, tools which work at the same spatiotemporal resolution as the receptor are exceptionally useful. To create such a tool, we designed a set of photoswitchable ligands based on the classical psychedelic N,N‐dimethyltryptamine (DMT). By incorporation of the DMT‐indole ring into the photoswitchable system, we obtained red‐shifted ligands which can be operated by visible light. Among these azo‐DMTs, compound 2 h ("Photo‐DMT") stands out as its cis isomer exhibits DMT like activity while the trans isomer acts as weak partial agonist. Such a cis‐on "efficacy switch" substantially expands the pharmacological toolbox to investigate the complex mechanisms of 5‐HT2AR signaling. [ABSTRACT FROM AUTHOR]

The construction of multi‐stereocenters by a transition metal‐catalyzed cross‐coupling reaction is a major challenge. The catalytic desymmetric functionalization of unactivated alkenes remains largely unexplored. Herein, we disclose ‐a desymmetric dicarbofunctionalization of 1,6‐dienes via a nickel‐catalyzed reductive cross‐coupling reaction. The leverage of the underdeveloped chiral 8‐Quinox enables the Ni‐catalyzed desymmetric carbamoylalkylation of both unactivated mono‐ and disubstituted alkenes to form pyrrolidinone bearing two nonadjacent stereogenic centers in high enantio‐ and stereoselectivitives with broad functional‐group tolerance. The synthetic application of pyrrolidinones allows the rapid access to complex chiral fused‐heterocycles. [ABSTRACT FROM AUTHOR]

Oligomeric acceptors are expected to combine the advantages of both highly developed small molecular and polymeric acceptors. However, organic solar cells (OSCs) based on oligomers lag far behind due to their slow development and low diversity. Here, three oligomeric acceptors were produced through oligomerization of small molecules. The dimer dBTICγ‐EH achieved the best power conversion efficiencies (PCEs) of 14.48 % in bulk heterojunction devices and possessed a T80 (80 % of the initial PCE) lifetime of 1020 h under illumination, which were far better than that of small molecular and polymeric acceptors. More excitingly, it showed PCEs of 16.06 % in quasi‐planar heterojunction (Q‐PHJ) devices which is the highest value OSCs using oligomeric acceptors to date. These results suggest that oligomerization of small molecules is a promising strategy to achieve OSCs with optimized performance between the high efficiency and durable stability, and offer oligomeric materials a bright future in commercial applications. [ABSTRACT FROM AUTHOR]

It is generally considered that photoacoustic imaging (PAI) and fluorescence imaging (FLI) cannot be enhanced concurrently, as they are dependent on competitive photophysical processes at the single‐molecule level. Herein, we reveal that BDTR9‐OC8 and BDTR9‐C8, which have identical π‐conjugated backbones but are substituted by side chains of different rigidity, show distinct phototheranostic properties in the aggregated state. The NIR‐II FLI and PAI brightness of BDTR9‐C8 nanoparticles are enhanced by 4.6 and 1.4 times compared with BDTR9‐OC8 nanoparticles. Theoretical calculations and GIWAXS analysis revealed that BDTR9‐C8 with rigid side chains shows a relative amorphous condensed state, which will benefit the efficient transportation of photo‐generated excitons and phonons, subsequently enhancing the FLI and PAI signals. Besides, both nanoparticles exhibit excellent photothermal conversion efficiency due to their strong light‐harvesting capability and are considered effective photothermal therapy materials. This work provides an illuminating strategy for material design in the future. [ABSTRACT FROM AUTHOR]

Classical psychedelics are a group of hallucinogens which trigger non‐ordinary states of consciousness through activation of the 5‐HT2A receptor (5‐HT2AR) in the brain. However, the exact mechanism of how 5‐HT2AR agonism alters perception remains elusive. When studying receptor signaling, tools which work at the same spatiotemporal resolution as the receptor are exceptionally useful. To create such a tool, we designed a set of photoswitchable ligands based on the classical psychedelic N,N‐dimethyltryptamine (DMT). By incorporation of the DMT‐indole ring into the photoswitchable system, we obtained red‐shifted ligands which can be operated by visible light. Among these azo‐DMTs, compound 2 h (“Photo‐DMT”) stands out as its cis isomer exhibits DMT like activity while the trans isomer acts as weak partial agonist. Such a cis‐on “efficacy switch” substantially expands the pharmacological toolbox to investigate the complex mechanisms of 5‐HT2AR signaling. [ABSTRACT FROM AUTHOR]