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Conformational isomerism of organic photovoltaic materials has a profound impact on their molecular packing and therefore performance of polymer solar cells (PSCs). However, the conformations of oligomeric acceptors (OAs) are mostly predicted by simulations rather than experimental determinations. Herein, the stereochemical S‐shaped structure of two dimeric‐type acceptor molecules, V‐DYIC and V‐DYIC‐4F, is first confirmed with different end groups (IC for V‐DYIC and IC‐2F for V‐DYIC‐4F), incorporating vinylene linkage for connecting the distinct state‐of‐the‐art small molecule acceptor Y‐segments. Through the synthetic control of fluorination sites adjacent to the vinyl‐linker, S‐shaped the conformation by NMR experiments is validated. Compared to the O‐shaped dimer, S‐shaped conformation results in enhanced lamellar order and reduced nonradiative recombination losses. The optimal acceptor, V‐DYIC‐4F, achieved a champion efficiency of 18.10% with the lowest energy loss of 0.556 eV in its devices paired with PM6 due to their efficient carrier transport, and suppressed recombination compared to other devices, being attributed to the synergistic effect of conformation and end group fluorination. The insights gained in this work contribute valuable knowledge of both synthetic control and structural determination of OAs, providing strategic design guidelines for the future development of dimeric acceptors toward high‐efficiency PSCs. [ABSTRACT FROM AUTHOR]

Among the most auspicious and efficient surface ligand candidates or additives to raise the efficiency of perovskite light‐emitting diodes (PeLEDs) are amino acids (AAs), possessing a combination of amino group and carboxylic group. The AA molecules exhibit significant promise for coherent tailoring their molecular conformations to yield remarkable advantages and multi‐functional properties. This raises a question that how PeLED devices can benefit greatly from the small amount of AA molecules integrated in perovskite films. In order to set up a structure–property relationship, the mysteries of the extraordinary improvement in performance of PeLEDs through AAs modification are disclosed. Furthermore, there is a critical discussion of workable guidelines for exploring AAs with optimal molecular conformations. Moreover, recent developments in blue, green, and red PeLED devices incorporating AAs are also highlighted in detail. Lastly, suggestions for future directions in research as well as the logical construction of functional AA molecules for potent and more stable PeLED devices are presented. [ABSTRACT FROM AUTHOR]

In view of the existence of an optimal conformation for molecular recognition and bearing in mind that nucleosides exhibit a broad range of pharmaceutical properties, whereby their conformation has a key role in molecular recognition, the tendency of the pseudosugar moiety in carbanucleosides to adopt a boat‐like conformation has been studied on the basis of a bicyclo[3.1.0]hexane system, resulting in versatile drug‐like scaffolds to increase molecular recognition. It is already known that using this system as pseudosugar can fix the conformation in the Northern or Southern geometry, required for biological activity, according to the relative position of the three‐member cycle. By mapping their energy potential surface, we investigate the preference for boat‐like conformers in bicyclo[3.1.0]hexanes. DFT is utilized alongside NBO analysis to explore the enhanced stability of boat‐like conformers, also considering the influence of oxygen, sulfur, and selenium heteroatoms. Additionally, charge density distribution analysis using QTAIM identifie key atoms contributing to stability changes. These findings will help to comprehend this behavior in the drug discovery process when conformationally restricted nucleosides are involved. [ABSTRACT FROM AUTHOR]

A microwave‐assisted synthesis of 7‐amino‐1,2,4‐triazolo[1,5‐a][1,3,5]triazine‐2‐propanamides was developed using a three‐component, catalyst‐free reaction of cyanamide and trimethyl orthoformate with 3‐(5‐amino‐1H‐1,2,4‐triazol‐3‐yl)propanamides (3). The reaction tolerated structurally diverse substrates and proceeded chemo‐ and regio‐selectively, affording the target compounds in high purity in 5–10 minutes. The convenient chromatography‐free isolation and purification of the products add practicality to this method. The structural features of the prepared compounds were investigated using dynamic NMR spectroscopy, X‐ray crystallography and computational chemistry calculations. X‐ray crystallography performed on a representative compound, 3‐(7‐amino‐1,2,4‐triazolo[1,5‐a][1,3,5]triazin‐2‐yl)‐N‐(4‐benzyl)propanamide (4 l), showed the overall molecular conformation to adopt the shape of the letter C. Notable localisation of π‐electron density is found within the 1,2,4‐triazolo[1,5‐a][1,3,5]triazine system; a relatively short C−NH2 bond is consistent with restricted rotation about this bond. This study also presents a detailed analysis of the molecular interactions in 4 l using DFT and QTAIM methods with a focus on the hydrogen‐bonding and π‐stacking interactions that influence the molecular packing of 4 l. The findings reveal the significant roles of N−H⋅O, N−H⋅N and C−H⋅N interactions, along with electrostatically enhanced π⋅π contacts. A broad screening for insecticidal, fungicidal and herbicidal properties identified several compounds with potent herbicidal activity against Matricaria inodora. [ABSTRACT FROM AUTHOR]

We report the crystal structures of three matrine derivatives, namely, the salts (1R,2R,9S,17S)‐6‐oxo‐7,13‐diazatetracyclo[7.7.1.02,7.013,17]heptadecan‐13‐ium (2E)‐3‐(3,4‐dihydroxyphenyl)prop‐2‐enoate (matrine caffeinate) sesquihydrate, C15H25N2O+·C9H7O4−·1.5H2O (Matrine–CA), and the 2‐hydroxybenzoate (salicylate) monohydrate, C15H25N2O+·C7H5O3−·H2O (Matrine–SA), as well as the 1.75‐hydrate form, (1R,2R,9S,17S)‐7,13‐diazatetracyclo[7.7.1.02,7.013,17]heptadecan‐6‐one 1.75‐hydrate, C15H24N2O·1.75H2O (Matrine–H). Each derivative exhibited a consistent molecular conformation for the matrine core, which is notably distinct from that of the anhydrous form. Notably, both salts crystallized in the orthorhombic space group P212121, with an asymmetric unit featuring one cation and one anion. Within the two salt structures, intermolecular proton transfer between matrine and the acid is observed, culminating in the formation of a matrine cation protonated at the tertiary amine N site. The Matrine–CA crystal packing is manifested as a three‐dimensional (3D) network arising from one‐dimensional (1D) supramolecular helical chains, stabilized by N—H...O and O—H...O hydrogen bonds. In the case of Matrine–SA, the matrine cation is interconnected via hydrogen bonds with salicylate anions and water molecules, also forming a 1D helical motif. The structure of the hydrate form, Matrine–H, is reported again with the disordered solvent molecules accurately located. To further elucidate the structural attributes, Hirshfeld surface analysis and fingerprint plots are employed, offering a nuanced perspective on the intermolecular contacts and interactions within these crystalline forms. [ABSTRACT FROM AUTHOR]

Summary: In this study, temperature‐dependent changes in the molecular conformation of curdlan were investigated using differential scanning calorimetry (DSC), microscopic observation, particle size analysis and molecular dynamics (MD) simulation. The DSC results showed that the gel formation temperature of curdlan is related to the glass transition temperature (Tg). The results of microscopic observation and particle size analysis showed that the curdlan particles swelled with increasing temperature, and the original rough and irregular surface morphology gradually became relatively smooth. The MD results show that the weak gel is the result of hydrogen bonds and hydrophobic interaction, whereas the strong gel is less affected by hydrogen bonds, and hydrophobic interaction is the main driving force. [ABSTRACT FROM AUTHOR]

A series of triphenylamine‐quinoxaline donor‐acceptor (bipolar) compounds (TPA‐QH, TPA‐QMe, TPA‐QCOOH and TPA‐QNO2) with different substituents were synthesized and investigated their fluorescence properties, including stimuli‐induced fluorescence responses in solution and the solid‐state. Single crystal structural analysis revealed non‐planar molecular conformation, substituent controlled intermolecular interactions and molecular packing in the crystal lattice. TPA‐QH, TPA‐QMe, TPA‐QCOOH and TPA‐QNO2 showed tunable solid‐state emission from green to red. TPA‐QH showed strong fluorescence at 487 nm (quantum yield (Φf)=28.3 %) whereas NO2 substituted TPA‐QNO2 exhibited relatively weak fluorescence at 610 nm (Φf=4.3 %). Density functional theoretical (DFT) calculations also indicated reduction of optical bandgap with substituting electron withdrawing group. The donor‐acceptor structure with intramolecular charge transfer (ICT) resulted solvent polarity dependent fluorescence tuning. The presence of acid responsive quinoxaline group was utilized to demonstrate pH‐responsive fluorescence switching and dual state fluorescence was utilized for fabricating rewritable fluorescent platform. Thus, the present study provides a structural insight to develop dual state emissive triphenylamine–quinoxaline based bipolar materials for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Förster resonance energy transfer (FRET) is an established tool for measuring distances between two molecules (donor and acceptor) on the nanometer scale. In the field of polymer science, the use of FRET to measure polymer end‐to‐end distances (Ree) often requires complex synthetic steps to label the chain ends with the FRET pair. This work reports an anthracene‐functionalized chain‐transfer agent for reversible addition‐fragmentation chain‐transfer (RAFT) polymerization, enabling the synthesized chains to be directly end‐labeled with a donor and acceptor without the need for any post‐polymerization functionalization. Noteworthily, this FRET method allows for chain conformation measurements of low molecular weight oligomers in situ, without any work‐up steps. Using FRET to directly measure the average Ree of the oligomer chains during polymerization, the chain growth of methyl methacrylate, styrene, and methyl acrylate is investigated as a function of reaction time, including determining their degree of polymerization (DP). It is found that DP results from FRET are consistent with other established measurement methods, such as nuclear magnetic resonance (NMR) spectroscopy. Altogether, this work presents a broadly applicable and straightforward method to in situ characterize Ree of low molecular weight oligomers and their DP during reaction. [ABSTRACT FROM AUTHOR]

Solution state 1H NMR spectroscopy provides valuable insights into molecular structure and conformation. However, when the spectrum exhibits severe signal overlap, it hampers the extraction of key structural information. Here, an ultraselective, ultrahigh resolution TOCSY method is introduced that greatly reduces spectral complexity, allowing the extraction of previously inaccessible spectral information. It combines the recently developed GEMSTONE excitation with homonuclear decoupling to provide highly simplified through‐bond correlation 1D 1H NMR spectra, showing all signals within the selected spin system as singlets. The new method can greatly facilitate the analysis of mixtures, as shown here for a mixture of Cinchona alkaloids (popular catalysts in asymmetric synthesis) and a mixture of glucocorticoids (used for treating conditions such as asthma). [ABSTRACT FROM AUTHOR]

Advancements in flexible electronic technology, especially the progress in foldable displays and under‐display cameras (UDC), have created an urgent demand for high‐performance colorless polyimide (CPI). However, current CPIs lack sufficient heat resistance for substrate applications. In this work, four kinds of rigid spirobifluorene diamines are designed, and the corresponding polyimides are prepared by their condensation with 5,5′‐(perfluoropropane‐2,2‐diyl) bis(isobenzofuran‐1,3‐dione) (6FDA) or 9,9‐bis(3,4‐dicarboxyphenyl) fluorene dianhydride (BPAF). The rigid and conjugated spirobifluorene units endow the polyimides with higher glass transition temperature (Tg) ranging from 356 to 468 °C. Their optical properties are regulated by small side groups and spirobifluorene structure with a periodically twisted molecular conformation. Consequently, a series of CPIs with an average transmittance ranging from 75% to 88% and a yellowness index (YI) as low as 2.48 are obtained. Among these, 27SPFTFA‐BPAF presents excellent comprehensive performance, with a Tg of 422 °C, a 5 wt.% loss temperature (Td5) of 562 °C, a YI of 3.53, and a tensile strength (δmax) of 140 MPa, respectively. The mechanism underlying the structure‐property relationship is investigated by experimental comparison and theoretical calculation, and the proposed method provides a pathway for designing highly rigid conjugated CPIs with excellent thermal stability and transparency for photoelectric engineering. [ABSTRACT FROM AUTHOR]

Light‐emitting organic small molecules require high internal and external quantum efficiencies with excellent radiative characteristics for their potential application in next‐generation optoelectronics. Nonetheless, achieving high efficiency in solid states remains a formidable challenge, primarily owing to the non‐radiative processes. Therefore, conformational modulation in solid states is pivotal in influencing emission properties to mitigate non‐radiative decay. Notably, modifying intra‐ and intermolecular non‐covalent interactions (NCIs) is a promising strategy that can simultaneously realize rigidity and stabilization of flexible single bonds, thus suppressing reorganization energy associated with non‐radiative decay. Consequently, considerable emission enhancement is attainable through adept manipulation of NCIs, corresponding to systems ranging from single molecules to multimolecular networks in solid states. This review systematically summarizes and analyzes the influence of diverse NCIs in efficient light‐emitting organic small molecules. The effects of NCIs on single‐and multimolecular‐systems are discussed, based on the fundamentals of light emission mechanism and the correlation between molecular design strategy and photophysical properties. Additionally, strategic perspectives are provided for the advancement of future light‐emitting organic small molecules. Therefore, this review serves as a comprehensive molecular design library, providing an up‐to‐date overview of molecular design leveraging NCIs for efficient light‐emitting organic small molecules. [ABSTRACT FROM AUTHOR]

The molecular conformation of giant molecule acceptors (GMAs) plays a significant role in regulating the intermolecular interactions and their photovoltaic performances in organic solar cells (OSCs). For the linear GMA GT‐l, the stronger homo‐molecular interaction causes its aggregation being weakly affected by the donor, thus forming an ordered molecular stacking and proper phase separation in its blend film. The star‐shaped GMA GT‐s‐based blend film shows a dominant hetero‐molecular interaction that suppresses the aggregation of the donor and acceptor, resulting in smaller phase separation and more uniform vertical phase distribution. While for another star‐shaped GMA GTs, the weakest hetero‐molecular interaction causes its blend film to form larger phase separation. Therefore, the GT‐l based OSC with PM6 as donor shows the highest charge mobilities, the fastest charge transfer (CT) process, reduced energy loss and less charge recombination, contributing to a higher power conversion efficiency (PCE) of 19.03%. Comparatively, the PCEs of the OSCs based on GTs and GT‐s are 18.05% and 17.58% respectively. Notably, all the three GMAs based OSCs show excellent thermal stability and long‐term storage stability. This study provides a facile strategy by tuning the linking unit and its connecting mode for designing highly efficient and stable organic photovoltaic materials. [ABSTRACT FROM AUTHOR]

The pressure response of crystalline trans‐cinnamic acid is studied by means of Raman spectroscopy up to 6 GPa. Pressure application causes the reversible shift of all the observed Raman peaks to higher frequencies and changes in their relative intensities, with the intermolecular vibrational modes being by far more sensitive to pressurization compared to the intramolecular ones. The present high‐pressure Raman data indicate the structural stability of the trans‐cinnamic acid crystal and molecular conformation up to the highest pressure attained in the experiments, the importance of the hydrogen bonding, as well as the considerable strengthening of the intermolecular interactions at elevated pressures. [ABSTRACT FROM AUTHOR]

Photo‐triggered phase transition is a new type of phase transition in which a photochromic crystal with a thermal phase transition transforms into an identical high‐temperature phase in a temperature region lower than the thermal phase transition temperature upon light irradiation. Here, we report a second crystal that exhibits a photo‐triggered phase transition, thereby demonstrating that the photo‐triggered phase transition is a general phenomenon that occurs in crystals. When the chiral salicylidenephenylethylamine crystal was irradiated with ultraviolet (UV) light, the photo‐triggered phase transition occurred in the temperature range −30 to −10 °C. The photo‐triggered phase transition is induced by local stress due to trans‐keto molecules produced by photoisomerization near the irradiated surface. Crystal cantilevers exhibited stepwise bending by the combination of the photo‐triggered phase transition and photoisomerization. Alternate irradiation with UV and visible light achieved locomotion of single crystals driven by repeated stepwise bending. Finally, a detailed comparison of photo‐triggered and non‐photo‐triggered phase transition crystals revealed that a sufficient molecular conformation change in affordable crystal voids, smooth photoisomerization, and most likely a chiral molecular arrangement are required for inducing the photo‐triggered phase transition. [ABSTRACT FROM AUTHOR]

Considering that regulation of thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) is necessary for a fluorophore to survive and properly show its characteristic features, it is successfully shown herein that a carefully designed novel pyrene derivative can exhibit remarkable aggregation‐induced emission (AIE) overcoming the characteristic fast excitonic decay of pyrene compounds. Moreover, it is established that J‐aggregation in the red‐emitting molecular crystals of the compound reduces the singlet‐triplet energy gap (∆EST), allowing TADF with a very high photoluminescence quantum yield (PLQY) of 72%. Whereas, anisotropic grinding of the same crystals generates well‐defined microcrystals that show RTP as the nature of aggregation changes. Impressively, under isotropic hydrostatic pressure, the crystals show near‐infra‐red (NIR) emission with a very high piezochromic luminescence sensitivity of 46.2 nm GPa−1. The results have established that formation of stable H‐aggregates in the microcrystals is responsible for the ultra‐long RTP. A highly sophisticated full‐spectrum Mueller‐matrix analysis is used for the first time in such systems to demonstrate the details of the effect of perturbation (pressure) on molecular conformation. [ABSTRACT FROM AUTHOR]

A molecular design strategy for the precise regulation of full‐color‐tunable emission organic luminescence materials is not yet systematically established for pyrene chemistry. To fabricate color‐tunable and highly‐efficiency pyrene‐based emitters, this article presents novel pyrene‐based molecules with donating‐π‐accepting structures, which exhibit bright, relatively narrow‐band FWHM emission, broad color‐tunable from deep blue (439 nm) to orange‐red (599 nm) both in solution and in the solid state. Moreover, the compounds 2a, 2d–g exhibit typical aggregation‐induced emission (AIE) characteristics, with an enhanced fluorescence quantum yield in the solid state. The experimental results indicated that the presence of the sterically bulky meta‐substituted biphenyl adopts an out‐of‐plane twist conformation, which can strengthen the rigidity of the molecular conformation and suppress the intermolecular π–π stacking in the aggregated state, resulting in an enhanced emission in the solid state. The prepared pyrene‐based AIEgens are applied as fluorescent inks to write Chinese characters and art with a vivid pattern. Thus, this article not only presents an efficient molecular strategy to construct pyrene‐based AIEgen with broad color‐tunable emission properties for practical applications, but also display a powerful combination of the strong alliance between the advanced luminescent materials, art and Chinese traditional culture. [ABSTRACT FROM AUTHOR]

The development of semiconducting polymers with good processability in green solvents and competitive electrical performance is essential for realizing sustainable large‐scale manufacturing and commercialization of organic electronics. A major obstacle is the processability‐performance dichotomy that is dictated by the lack of ideal building blocks with balanced polarity, solubility, electronic structures, and molecular conformation. Herein, through the integration of donor, quinoid and acceptor units, an unprecedented building block, namely TQBT, is introduced for constructing a serial of conjugated polymers. The TQBT, distinct in non‐symmetric structure and high dipole moment, imparts enhanced solubility in anisole—a green solvent—to the polymer TQBT‐T. Furthermore, PTQBT‐T possess a highly rigid and planar backbone owing to the nearly coplanar geometry and quinoidal nature of TQBT, resulting in strong aggregation in solution and localized aggregates in film. Remarkably, PTQBT‐T films spuncast from anisole exhibit a hole mobility of 2.30 cm2 V‐1 s‐1, which is record high for green solvent‐processable semiconducting polymers via spin‐coating, together with commendable operational and storage stability. The hybrid building block emerges as a pioneering electroactive unit, shedding light on future design strategies in high‐performance semiconducting polymers compatible with green processing and marking a significant stride towards ecofriendly organic electronics. [ABSTRACT FROM AUTHOR]

π‐Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry and materials science. We present the design principles to access new chiral macrocycles (1 and 2) that are essentially built on the key components of main‐group electron‐donating carbazolyl moieties or the π‐expanded aza[7]helicenes. Both macrocycles show the unique molecular conformations with a (quasi) figure‐of‐eight topology as a result of the conjugation patterns of 2,2',7,7'‐spirobifluorenyl in 1 and triarylamine‐coupled aza[7]helicene‐based building blocks in 2. This electronic nature of redox‐active, carbazole‐rich backbones enabled these macrocycles to be readily oxidized chemically and electrochemically, leading to the sequential production of a series of positively charged polycationic open‐shell cyclophanes. Their redox‐dependent electronic states of the resulting multispin polyradicals have been characterized by VT‐ESR, UV/Vis‐NIR absorption and spectroelectrochemical measurements. The singlet (ΔES‐T=−1.29 kcal mol−1) and a nearly degenerate singlet‐triplet ground state (ΔES−T(calcd)=−0.15 kcal mol−1 and ΔES−T(exp)=0.01 kcal mol−1) were proved for diradical dications 12+2⋅ and 22+2⋅, respectively. Our work provides an experimental proof for the construction of electron‐donating new chiral nanorings, and more importantly for highly charged polyradicals with potential applications in chirospintronics and organic conductors. [ABSTRACT FROM AUTHOR]

This paper reports five novel PDI dimer type electron transport materials (ETMs) employing o‐indoloquinoxaline (o‐Iq), m‐indoloquinoxaline (m‐Iq), and cibalackrot (Ci) groups as the core building blocks and presents the twisted structures of PDI dimers coded as PDI‐NHR‐o‐Iq, PDI‐o‐Iq, PDI‐NHR‐m‐Iq, PDI‐m‐Iq and PDI‐NHR‐Ci dyes (see Scheme 1 and 2). We have systematically compared their photophysical, electrochemical, and optoelectronic properties with respect to the reference dye (2PDI‐NHR), which is directly connected of two PDI planes. Their calculated HOMO‐LUMO energy levels are sufficient for charge transfer to the perovskite material so that structure‐photovoltaic performance relationship of synthesized ETM dyes can be evaluated. When the binding position of indoloquinoxaline group between PDI rings are changed from o‐ to m‐ positions, most of the photophysical and electrochemical properties of PDI dimer are dramatically changed, finally improving the photovoltaic performances. [ABSTRACT FROM AUTHOR]

The molecular conformation, crystalline morphology, and properties of photochromic organic crystals can be controlled through photoirradiation, making them promising candidates for functional organic materials. However, photochromic porous molecular crystals with a networked framework structure are rare due to the difficulty in maintaining space that allows for photo‐induced molecular motion in the crystalline state. This study describes a photo‐responsive single crystal based on hydrogen‐bonded (H‐bonded) network of dihydrodimethylbenzo[e]pyrene derivative 4BDHP. A crystal composed of H‐bonded undulate layers, 4BDHP‐2, underwent photo‐isomerization in the crystalline state due to loose stacking of the layers. Particularly, enantio‐pure crystal (S,S)‐4BDHP‐2 allowed to reveal the structure of the photoisomerized crystal, in which the closed form (4BDHP) and open form (4CPD) were arranged alternately with keeping crystalline periodicity, although side reactions were also implied. The present proof‐of‐concept system of a photochromic framework that retains crystalline periodicity after photo‐isomerization may provide new light‐driven porous functional materials. [ABSTRACT FROM AUTHOR]

Polymorphism‐dependent cytotoxicity and cellular uptake of drug molecules have been studied for the past two decades. However, the visualization of polymorph‐dependent cellular uptake and cytotoxicity using microscopy imaging techniques has not yet been reported. The luminescent polymorph is an ideal candidate to validate the above hypothesis. Herein, we report the polymorph‐dependent cellular uptake, cytotoxicity, and bio‐imaging functions of polymorphs 1Y and 1R of a naphthalimide‐phenothiazine dyad. These polymorphs show different luminescence colors in the solid state and exhibit aggregation‐induced enhanced emission (AIEE) in the DMSO‐Water mixture. Bioimaging, cytotoxicity assay, and fluorescence‐activated cell sorting (FACS) studies revealed that these polymorphs show different levels of cytotoxicity, cellular uptake, localization, and imaging potential. Detailed photophysical, morphological, and biological studies revealed that the difference in molecular conformation in these polymorphs enables them to form aggregates of different sizes and morphology, which leads to the differential uptake of these into the cells and consequently shows different cytotoxicity and imaging potentials. [ABSTRACT FROM AUTHOR]

The ternary complexes of the zinc(II), [Zn(met)(gly)(Cl)2] (1), and [Zn(met)(hist)(Cl)2] (2) are synthesized and illustrated utilizing spectroscopic and analytical measurements, and the geometry of the complexes has been identified to be octahedral. The Coats Red fern approach was employed to enumerate the thermodynamic and kinetic variables for both the Zn(II) complexes' decomposition. The quantum chemical variables were estimated utilizing the molecular orbital conformations' energy distribution, which was derived from optimal geometric shapes to test the stabilization of both complexes. DNA‐binding investigations by UV–Vis absorption, fluorescence, and viscosity were all exploited to examine the bonding properties between Zn(II) complexes and ct‐DNA, and a groove mode of bonding was established. The interactions between complexes and BSA/HSA were investigated by employing absorption and emission spectroscopic methods. The results demonstrate that complexes have a powerful ability to diminish BSA and HSA luminescence intensity, and overall associating mode is predominantly a static quenching process. The cytotoxic effect of the two Zn(II) complexes was additionally examined in human breast adenocarcinoma (MCF‐7 and MDA‐MB‐231) cell lines by employing the MTT technique. The IC50 values for every cell line were derived. Each of the two complexes was functional in both cell lines. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs), which are the hubs of lipid metabolism, play a critical role in maintaining cellular energy homeostasis. The construction of advanced photosensitizers (PSs) capable of manipulating LD‐mediated cell fate regulation is highly desirable though rarely reported. In this study, a near‐infrared emissive PS (DPCMP) with LDs specificity was synthesized and successfully applied to induce ferroptosis and apoptosis. DPCMP exhibited typical aggregation‐induced emission characteristics owing to its twisted molecular conformation. Excellent biocompatibility and suitable lipophilicity allowed DPCMP to specifically stain the LDs in living cells. Under white light illumination, the DPCMP displayed potent reactive oxygen species (ROS) generation capacity through both type I and II photochemistry. The massive accumulation of lethal ROS generated by DPCMP‐mediated photosensitization initiated lipid peroxidation, impaired cellular redox homeostasis, and led to endoplasmic reticulum oxidative stress, ultimately inhibiting cellular proliferation via concurrent ferroptosis and apoptosis in both living cancer cells and multicellular tumor spheroids. [ABSTRACT FROM AUTHOR]

A newly synthesized N,N′-dipropyl-substituted isoindigo derivative, namely, 1-propyl-3-(1-propyl-1,2-dihydro-2-oxo-3H-indol-3-ylidene)-1,3-dihydro-2H-indol-2-one, C22H22N2O2, was found to have three polymorphic forms (denoted Forms I, II and III) under various crystallization conditions. Crystal structure analysis indicated that Form III had a significantly different molecular conformation from the other two polymorphs. Their different packing arrangements were correlated with differences in the intermolecular interactions. Thermal measurements revealed that Forms I and II are enantiotropically related, and Form II exhibits thermally dynamic behaviour. [ABSTRACT FROM AUTHOR]

In order to improve the performance of organic luminescent materials, lots of studies have been carried out at the molecular level. However, these materials are mostly applied as solids or aggregates in practical applications, in which the relationship between aggregation structure and luminescent property should be paid more attention. Here, we obtained five phenothiazine 5,5‐dioxide (O‐PTZ) derivatives with distinct molecular conformations by rational design of chemical structures, and systematically studied their room‐temperature phosphorescence (RTP) effect in solid state. It was found that O‐PTZ dimers with quasi‐equatorial (eq) conformation tended to show stronger π‐π interaction than quasi‐axial (ax) conformers in crystal state, which was more conducive to the generation of RTP. Based on this result, a multi‐level structural model of organic solids was proposed to draw the relationship between aggregation structure and RTP effect, just like the research for the structure‐property relationship of proteins. Using this structural model as the guide, boosted RTP efficiency from 1% to 20% was successfully achieved in the corresponding host‐guest doping system, showing its wide applicability. [ABSTRACT FROM AUTHOR]

Molecular emitters with multi‐emissive properties are in high demand in numerous fields, while these properties basically depend on specific molecular conformation and packing. For amorphous systems, special molecular arrangement is unnecessary, but it remains challenging to achieve such luminescent behaviors. Herein, we present a general strategy that takes advantage of molecular rigidity and S1‐T1 energy gap balance for emitter design, which enables fluorescence–phosphorescence dual‐emission properties in various solid forms, whether crystalline or amorphous. Subsequently, the amorphism of the emitters based polymethyl methacrylate films endowed an in situ regulation of the dual‐emissive characteristics. With the ratiometric regulation of phosphorescence by external stimuli and stable fluorescence as internal reference, highly controllable luminescent color tuning (yellow to blue including white emission) was achieved. There properties together with a persistent luminous behavior is of benefit for an irreplaceable set of optical information combination, featuring an ultrahigh‐security anti‐counterfeiting ability. Our research introduces a concept of eliminating the crystal‐form and molecular‐conformational dependence of complex luminescent properties through emitter molecular design. This has profound implications for the development of functional materials. [ABSTRACT FROM AUTHOR]

Organic room‐temperature phosphorescence (RTP) from triplet excitons has shown great potential for biological imaging and sensing, but these applications in aqueous environments are often limited by the moisture‐mediated phosphorescence quenching. Water‐induced enhancement of RTP can overcome this limitation, but the underlying mechanism remains unclear. This study focuses on two control prototypes CT and CTW, composed of trimesic acid (TMA, guest) and cyanuric acid (CA, host), while CTW introduces 20 wt.% water to CT, leading to enhanced RTP. Theoretical calculations demonstrate that the molecular conformation of TMA manipulated by intermolecular interactions governs the RTP property of aggregates. From CT to CTW, the TMA tends to a more coplanar geometry due to the decreased values in the span of deviation from plane. This conformational change not only increases the spin‐orbit coupling (SOC) of S1→Tn, thereby accelerating the intersystem crossing process and radiative transition for promoting RTP efficiency, but also reduces the SOC of T1→S0, suppressing the non‐radiative transition to prolong RTP lifetime. Exciton dynamics reproduce the prolonged RTP lifetime from CT to CTW in experiments, which is dominated by the SOC, rather than the electron‐vibration coupling. The findings offer novel insights for developing water‐doped materials with improved RTP performance. [ABSTRACT FROM AUTHOR]

The fine structural–functional construction of organic semiconductor materials provides an abundant candidate store for the hole‐transport materials (HTMs) in perovskite solar cells (PSCs). Whereas, challenges remain in unveiling the clews behind the molecular conformation engineering and desired properties realizing for efficient HTMs. In this work, a couple of simple organic diphenylfluorene‐cored isomers (FH27 and FH99) with different spatial integration strategies of molecular conformation are judiciously devised as HTMs in the PSCs. The theoretical simulation and experimental analyses decipher that the excellent electronic/energetic distribution, intermolecular stacking geometry, intrinsic solid‐crystal film morphology, and charge‐extraction‐transport ability are demonstrated for FH27, ascribing to its harmonious intersectional couplings for the planar/orthogonal molecular conformation. The FH27‐based device achieves a high efficiency of 23.61% with benign life span, both superior to the FH99‐based device. [ABSTRACT FROM AUTHOR]

It is well known that triplet–triplet annihilation upconversion (TTU) can enhance electroluminescence (EL) efficiency by converting two low‐energy triplet excitons into one high‐energy singlet exciton. However, conventional intermolecular TTU requires high doping concentration to activate, limiting device architecture. Here, six dimer molecules comprised of two anthracene units connected by a spacer unit are investigated, which have a possibility of the intramolecular TTU process. As a result, two dimer molecules show high TTU efficiencies close to the theoretical maximum even in dispersed, diluted conditions. By comparing these molecular conformations, a correlation is found between the dimer structures of two anthracene units and the TTU activity in the diluted condition, i.e., the 3D molecular structure with the exciton utilizing efficiency. [ABSTRACT FROM AUTHOR]

The investigation of organic light‐emitting diodes (OLEDs) and organic laser devices with thermally activated delayed fluorescence (TADF) molecules is emerging due to the potential of harnessing triplets. In this work, a boron/nitrogen multiple‐resonance TADF polycyclic framework fusing carbazole units (CzBNPh) was proposed. CzBNPh exhibited a narrowband emission (<30 nm), a unity photoluminescence quantum yield, and a fast radiative rate. Consequently, CzBNPh demonstrated a low distributed feedback (DFB) lasing threshold of 0.68 μJ cm−2. Furthermore, the stimulated emission zone of CzBNPh was effectively separated from its singlet and triplet absorption, thereby minimizing the singlet‐triplet annihilation under long‐pulsed excitation ranging from 20 μs to 2.5 ms. Significantly, the enhanced rigid molecular conformation, thermal stability, and photo‐stability resulted in improved lasing and electroluminescence stability compared to that of 5,9‐diphenyl‐5,9‐diaza‐13b‐boranaphtho[3,2,1‐de]anthracene (DABNA)‐core. These findings indicate the potential of CzBN‐core as a promising framework for achieving long‐pulsed wave and electrically‐pumped lasing in the future. [ABSTRACT FROM AUTHOR]

The concept of a domino‐type reaction has been applied in a wide range of fields such as synthetic organic chemistry, material engineering, and life science. To extend the domino concept to redox chemistry, we designed and synthesized a dimeric quinodimethane (QD) with a nonplanar dithiin spacer. The domino‐redox properties can be activated by raising the temperature, based on a thermally equilibrated twisted conformation of QD, which has a higher HOMO level that is more readily oxidized. After one QD unit is oxidized (trigger), steric repulsion and electronic interaction between electrophores make the neighboring QD unit adopt a twisted conformation (domino process), which facilitates the following oxidation. Thus, a domino‐redox reaction was achieved for the first time by a change in the HOMO level due to a drastic change in the molecular conformation. [ABSTRACT FROM AUTHOR]

Diarylethenes (DAEs) exhibiting photochromic behavior have emerged as a popular research topic owing to their superior thermal stability, rapid photo‐responsiveness, robust fatigue resistance, and remarkable solution/solid‐state photochromic properties. However, the overlapped reading wavelength and absorption of DAEs can lead to a partial photochromic reaction, resulting in destructive readout that erodes pre‐existing information in memory and data processing. To address this issue, researchers have implemented a range of strategies, including gated reactivity, infrared (IR) absorption, and Raman scattering readout. Among them, gating functions as a "key" or "lock" to regulate the photochromic reactivity through external stimuli, such as reactions, chemicals, additional photons, or heat, making it a viable solution. This review presents a summary of recent developments in gated DAEs, with a particular focus on gating strategies and principles, including modulation of the 1,3,5‐hexatriene moiety and molecular conformation, and regulation of activation energy. Additionally, the challenges and opportunities of gated DAEs systems for future non‐destructive readout and functional materials are also discussed. [ABSTRACT FROM AUTHOR]

A new organic molecule is found to be able to form different fluorescent aggregation states in both single crystals and powders. When irradiated with ultraviolet light, single crystals and powders exhibit an in situ change in the fluorescence color from blue to green and then to chartreuse without changing the chemical groups. This stems from photoinduced changes in the molecular conformation and packing in the solid state. Two or three fluorescence colors can be displayed simultaneously in a single organic crystal by controlling the irradiation time. Under irradiation with intense ultraviolet light, deformations, movements and in situ welding of crystals can be achieved by utilizing the photothermal effect. This work demonstrates a new strategy for inducing different behaviors of organic solid state with stimulation by single‐wavelength light. [ABSTRACT FROM AUTHOR]

Summary: The objective of the study was to investigate the configurational changes and aggregation mechanism of wheat gluten induced by sodium chloride (NaCl) and sodium carbonate (Na2CO3). The results showed that NaCl shielded surface charges of gluten, developed more hydrogen bonds with tyrosine, and stabilised the secondary structure, while Na2CO3 promoted significant transition of the secondary structure from random coils and β‐turn to β‐sheet. Both NaCl and Na2CO3 quenched tryptophan fluorescence and promoted the aggregation of gluten subunits, where Na2CO3 induced covalent bond formation other than disulphides and facilitated gluten network development. Atomic force microscopy images confirmed different molecular surface features in gluten network. In conclusion, both NaCl and Na2CO3 demonstrated the ability to promote rheology, aggregation, and network formation of gluten but different molecular mechanisms were involved. This work provides valuable insights for the processing of salted and alkaline noodles. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) have attracted wide research attention in the past decades. Very recently, oligomerized fused‐ring electron acceptors (OFREAs) have emerged as a promising alternative to small‐molecular/polymeric acceptor‐based OSCs due to their unique advantages such as well‐defined structures, batch reproducibility, good film formation, low diffusion coefficient, and excellent stability. So far, rapid advances have been made in the development of OFREAs consisting of directly/rigidly/flexibly linked oligomers and fused ones. In this Minireview, we systematically summarized the recent research progress of OFREAs, including structural diversity, synthesis approach, molecular conformation and packing, and long‐term stability. Finally, we conclude with future perspectives on the challenges to be addressed and potential research directions. We believe that this Minireview will encourage the development of novel OFREAs for OSC applications. [ABSTRACT FROM AUTHOR]

Benzo[d][1,2,3]triazole (BTA) unit is one of the most classic electron‐accepting units (A) to construct donor (D)‐π‐A‐type photovoltaic polymers. However, the highest power conversion efficiency (PCE) of organic photovoltaics (OPVs) based on BTA‐containing polymers is restricted to 15–16%, lagging other promising polymers. Thus, investigating the structure‐performance relationship and breaking the efficiency bottleneck of BTA‐based polymers is challenging but critical. Herein, the effects of fusing two thiophene rings at D (PE52), π (PE4), and A (PE39) units of a classic D–π–A‐type BTA‐containing polymer J52‐Cl, respectively, on the backbone conformation, crystallinity, molecular stacking, and photovoltaic performance are systematically investigated. When blended with a BTA‐containing non‐fullerene acceptor (NFA), Y18, all three polymers with extending conjugated backbones can decrease the energy loss of photovoltaic devices. Notably, PE4, with a linear backbone conformation, realizes the champion PCE of 17.08%, with a short‐circuit current density (JSC) of 26.83 mA cm−2, a large breakthrough for BTA‐based photovoltaic polymers. What's more, the photovoltaic device based on PE4:Y18 combination fabricated by a non‐halogenated solvent of o‐xylene also displays an excellent PCE of 16.87%. The results indicate that fusing thiophene rings to BTA‐polymers, especially at π‐bridge, is a simple and effective method to improve the photovoltaic performance via modulating the molecular conformation and crystallinity. [ABSTRACT FROM AUTHOR]

The determination of molecular conformations of oligomeric acceptors (OAs) and their impact on molecular packing are crucial for understanding the photovoltaic performance of their resulting polymer solar cells (PSCs) but have not been well studied yet. Herein, we synthesized two dimeric acceptor materials, DIBP3F‐Se and DIBP3F‐S, which bridged two segments of Y6‐derivatives by selenophene and thiophene, respectively. Theoretical simulation and experimental 1D and 2D NMR spectroscopic studies prove that both dimers exhibit O‐shaped conformations other than S‐ or U‐shaped counter‐ones. Notably, this O‐shaped conformation is likely governed by a distinctive "conformational lock" mechanism, arising from the intensified intramolecular π–π interactions among their two terminal groups within the dimers. PSCs based on DIBP3F‐Se deliver a maximum efficiency of 18.09 %, outperforming DIBP3F‐S‐based cells (16.11 %) and ranking among the highest efficiencies for OA‐based PSCs. This work demonstrates a facile method to obtain OA conformations and highlights the potential of dimeric acceptors for high‐performance PSCs. [ABSTRACT FROM AUTHOR]

Understanding the molecular basis for protein stability requires a thermodynamic analysis of protein folding. Thermodynamic analysis is often performed by sampling many atomistic conformations using molecular simulations that employ either explicit or implicit water models. However, it remains unclear to what extent thermodynamic results from different solvation models are reliable at the molecular level. In this study, we quantify the influence of both solvation models on folding stability at the individual backbone and side chain resolutions. We assess the residue‐specific folding free energy components of a β‐sheet protein and a helical protein using trajectories resulting from TIP3P explicit and generalized Born/surface area implicit solvent simulations of model proteins. We found that the thermodynamic discrepancy due to the implicit solvent mostly originates from charged side chains, followed by the under‐stabilized hydrophobic ones. In contrast, the contributions of backbone residue in both proteins were comparable for explicit and implicit water models. Our study lays out the foundation for detailed thermodynamic assessment of solvation models in the context of protein simulation. [ABSTRACT FROM AUTHOR]

To exploit the potential of our newly developed three‐dimensional (3D) dimerized acceptors, a series of chlorinated 3D acceptors (namely CH8‐3/4/5) were reported by precisely tuning the position of chlorine (Cl) atom. The introduction of Cl atom in central unit affects the molecular conformation. Whereas, by replacing fluorinated terminal groups (CH8‐3) with chlorinated terminal groups (CH8‐4 and CH8‐5), the red‐shift absorption and enhanced crystallization are achieved. Benefiting from these, all devices received promising power conversion efficiencies (PCEs) over 16 % as well as decent thermal/photo‐stabilities. Among them, PM6:CH8‐4 based device yielded a best PCE of 17.58 %. Besides, the 3D merits with multi alkyl chains enable their versatile processability during the device preparation. Impressive PCEs of 17.27 % and 16.23 % could be achieved for non‐halogen solvent processable devices prepared in glovebox and ambient, respectively. 2.88 cm2 modules also obtained PCEs over 13 % via spin‐coating and blade‐coating methods, respectively. These results are among the best performance of dimerized acceptors. The decent performance of CH8‐4 on small‐area devices, modules and non‐halogen solvent‐processed devices highlights the versatile processing capability of our 3D acceptors, as well as their potential applications in the future. [ABSTRACT FROM AUTHOR]

The commercialization of organic solar cells (OSCs) requires both high power conversion efficiency (PCE) and long‐term stability. However, the lifetime of the OSCs containing small‐molecule acceptors (SMA) should be significantly enhanced. In this study, a series of planarity‐controlled is developed, high electron mobility dimerized SMAs (DSMAs) and realize OSCs with high‐performance (PCE = 18.8%) and high‐stability (t80% lifetime = 5380 h under 1‐Sun illumination). An acetylene linker with a planar triple bond is designed for dimerization of SMA units to afford the high backbone planarity necessary to achieve high crystallinity and electron mobility. To further engineer the molecular conformation and electron mobility of the DSMAs, different regioisomers of a Y‐based SMA are dimerized to yield three regioisomerically distinct DSMAs, denoted as DYA‐I, DYA‐IO, and DYA‐O, respectively. It is found that the crystallinity, electron mobility, and glass transition temperature of the DSMAs gradually increase in the order of DYA‐O, DYA‐IO, and DYA‐I, which, in turn, enhance the PCE and device stability of the resulting OSCs; DYA‐O (PCE = 16.45% and t80% lifetime = 3337 h) < DYA‐IO (PCE = 17.54% and t80% lifetime = 4255 h) < DYA‐I (PCE = 18.83% and t80% lifetime = 5380 h). [ABSTRACT FROM AUTHOR]

In this article, a fluid flow and heat transfer model which consist of the mass, momentum, and energy conservation equations together with the level set equation and Rolie‐Poly constitution equation is proposed and applied to simulate the rheological behaviors of viscoelastic polystyrene melt in the filling process of injection molding. The macroscopic velocity, pressure, temperature, stress, and mesoscopic molecular conformation of polystyrene melt are shown and analyzed detailedly during the mold filling process. The single‐mode Rolie‐Poly model is employed to describe the stress–strain relationship of polystyrene melt, and the level set method is used to capture the evolution of melt front interface. The governing equations for polymer melt are discretized by the finite volume method on collocated mesh, and solved by the SIMPLE algorithm. Numerical simulations have been implemented based on rectangular cavities with different gate locations, and rectangular and circular inserts. Numerical results indicate that the gate locations, gate numbers, insert size and shape are major factors that affect the rheological behaviors of polystyrene melt in the filling stage of injection molding, and polymer chains experienced higher shear and extension effects in the regions near to mold walls and obstacle. In addition, the length and position of weld lines are discussed in the current study. [ABSTRACT FROM AUTHOR]

The conversion/alloying‐type electrode has promising potential in next‐generation large‐scale energy storage. However, it is plagued by vast volume expansion, the sluggish ion transport capability due to the anion migration and the deficient geometric conformation. Herein, an ultrastable Sb2Se3 anode is elaborately designed for potassium‐ion batteries (PIBs) through combined strategies of expedited side‐chain transport with bulky polar groups and stable molecular conformations. By rendering flexible polymer conductor (PC), hyaluronic acid conjugated dopamine, (named as HD) with a dissociated tetraethylthiuram disulfide (TETD) side chain, i.e., THD, via the in situ growth protocol over the hollow nitrogen‐doped polyhedron carbon (NC) confined Mn‐Sb2Se3 nanospheres (THD/Mn‐Sb2Se3@NC) grafting multipolar intramolecular covalent bonds, the fabricated THD/Mn‐Sb2Se3@NC displays gloriously enhanced side chain transport capability along with planarity and rigidity, benefiting from the finely decoupled segmental motion of the polymer chains and the dislocated π–π electrons. Consequently, THD/Mn‐Sb2Se3@NC exhibits superior fast‐charging behavior with a wider temperature adaptability from −50 °C to 80 °C. The findings provide fundamental guidance for developing advanced electrodes with outstanding side chain transport kinetics that go beyond safe, high‐performance PIBs. [ABSTRACT FROM AUTHOR]

Transferulic acid has therapeutic importance hence it is very crucial to understand how this molecule interacts with lysozyme proteins for the purpose of drug design, and evaluation. The study is very helpful for drug pharmacology and the thermodynamic parameters of the polyphenolic compound and this protein interaction which is important for disease encounter and prevention. Here the spectroscopic, thermodynamic, and computational study has been reported as experiments. The CD study of the binding of lysozyme and trans ferulic acid found significant structural stability of the protein. Spectroscopically the UV‐Vis & fluorescence study has shown a substantial shift of absorption spectra in the binding of these two molecules, to confirm the interaction. An ITC experimental study found an affinity of the molecule to protein with a binding constant of Ka having a significant value. The Molecular Dynamics study found details of the geometric posture and main force of binding of TFA molecule upon binding with lysozyme site in PBS buffer at physiological pH value. The complex of lysozyme and trans ferulic acid also proved as a stable conformation by Molecular Dynamics study. In the DSC study, stable interaction of lysozyme and trans ferulic acid is shown upon changing the melting enthalpies and temperatures. [ABSTRACT FROM AUTHOR]

The induction time for nucleation can differ based on the solutions used to conduct a crystallization, which can in turn impact the efficiency and economics of a crystallization process, the crystal size distribution, the morphology and ultimately functionality of the final product. Establishing a link between the nucleation pathway/solution structure and nucleation induction time is essential to achieve improved comprehension of the process of crystal nucleation from solution. In this study, the role of solute conformation, solvent–solute interaction, and solute–solute interaction in nucleation was examined using tolbutamide as a model compound in toluene and toluene–alcohol solutions. Through a combination of induction time experiments, attenuated total reflection Fourier transformed infrared spectroscopy, nuclear magnetic resonance spectroscopy, molecular dynamics simulations, and quantum chemical calculations, it was found that not only solvent–solute interactions but also solute–solute interactions and structural similarities between molecular self‐assemblies in the solution and synthons in the crystal structure, can significantly influence the nucleation induction time. [ABSTRACT FROM AUTHOR]

Considerable progress on high‐performance organic solar cells (OSCs) has been achieved in the past due to the rapid development of nonfullerene acceptors (NFAs). Typically, two kinds of methods have been employed to manipulate energy levels and aggregation of NFAs, i.e., molecular engineering on alkyl side chains and modification of the heterocyclic rings in the backbone. Herein, a novel asymmetric thiophene[3,2‐b] pyrrole (TP)‐based NFA with flipped molecular conformation, named as PTBTT‐4F, is designed and synthesized. The introduction of the pyrrole ring in the novel NFA would not only afford extra reaction sites for side chain modification, but also induce substantial intramolecular charge transfer, thus leading to elevated energy levels of the NFA and thereby lower energy loss of the OSCs. When pairing with polymer donor PBDB‐TF to fabricate OSCs, concurrent improvement in open‐circuit voltage, short‐circuit current (JSC), and fill factor (FF) is realized, which delivers an outstanding power conversion efficiency (PCE) of 14.49%. Benefitting from effective molecular stacking and optimized phase separation induced by molecular conformation variation, asymmetric PTBTT‐4F fabricated OSCs exhibit much higher JSCs and FFs than the symmetrical PTBTP‐4F devices. [ABSTRACT FROM AUTHOR]

Aromatic amides can be used to construct light‐harvesting materials with valuable optical properties. The amide bond is formed using well‐known coupling agents in near quantitative yield, as illustrated here through the synthesis of two boron dipyrromethene derivatives bearing an amide linkage. The primary concern with acyl amides is rotation around the C−N bond, leading to cis and trans isomers. Using NMR spectroscopy, quantum chemical calculations and critical comparison to simpler benzamides, the stereochemistry of the target compounds has been addressed. The N‐cyclohexyl derivative gave diffraction quality crystals that established a trans geometry for the amide bond. Quantum chemical calculations support the trans geometry as being the lowest‐energy structure in solution but indicate that inversion of the aryl ring is an important structural feature. Indeed, rotation around the C(sp2)−C(aryl) bond has a strong influence on the solution‐phase NMR spectra. The amide connection has minimal effect on the photophysical properties. [ABSTRACT FROM AUTHOR]

A concise and versatile synthesis of 5‐(arylmethylideneamino)‐4‐(1H‐benzo[d]imidazol‐1‐yl)pyrimidines has been developed, starting from 4‐(1H‐benzo[d]imidazol‐1‐yl)pyrimidines, and we report here the synthesis and spectroscopic and structural characterization of three such products, along with those of two intermediates in the reaction pathway. The intermediates 4‐[2‐(4‐chlorophenyl)‐1H‐benzo[d]imidazol‐1‐yl]‐6‐methoxypyrimidine‐2,5‐diamine, (II), and 4‐[2‐(4‐bromophenyl)‐1H‐benzo[d]imidazol‐1‐yl]‐6‐methoxypyrimidine‐2,5‐diamine, (III), crystallize as the isostructural monohydrates C18H15ClN5O·H2O and C18H15BrN5O·H2O, respectively, in which the components are linked into complex sheets by O—H…N and N—H…O hydrogen bonds. In the product (E)‐4‐methoxy‐5‐[(4‐nitrobenzylidene)amino]‐6‐[2‐(4‐nitrophenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidin‐2‐amine, which crystallizes as a 1:1 solvate with dimethyl sulfoxide, C25H18N8O5·C2H6OS, (IV), inversion‐related pairs of the pyrimidine component are linked by N—H…N hydrogen bonds to form cyclic centrosymmetric R22(8) dimers to which pairs of solvent molecules are linked by N—H…O hydrogen bonds. (E)‐4‐Methoxy‐5‐[(4‐methylbenzylidene)amino]‐6‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidin‐2‐amine, C27H24N6O, (V), crystallizes with Z′ = 2 and the molecules are linked into a three‐dimensional framework structure by a combination of N—H…N, C—H…N and C—H…π(arene) hydrogen bonds. The analogous product (E)‐4‐methoxy‐5‐[(4‐chlorobenzylidene)amino]‐6‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidin‐2‐amine, C26H21ClN6O, (VI), crystallizes from dimethyl sulfoxide in two forms: one, denoted (VIa), is isostructural with (V), and the other, denoted (VIb), crystallizes with Z′ = 1, but as an unknown solvate in which the pyrimidine molecules are linked by N—H…N hydrogen bonds to form a ribbon containing two types of centrosymmetric ring.A versatile synthesis is reported for 5‐(arylmethylideneamino)‐4‐(1H‐benzo[d]imidazol‐1‐yl)pyrimidines and structures are reported for three examples, one of them in two crystal forms, as well as for two intermediates in the synthetic sequence. A diverse range of hydrogen‐bonding patterns leads to supramolecular assemblies ranging from finite zero‐dimensional aggregates to three‐dimensional framework structures. [ABSTRACT FROM AUTHOR]

Currently, n‐type small‐molecule mixed ionic‐electronic conductors remain less explored and their molecular design rules are not mature enough. Herein, two n‐type glycolated imide‐fused polycyclic aromatic hydrocarbons (IPAHs), d‐gdiPDI and t‐gdiPDI, are developed to probe the effects of molecular conformation on the electronic, electrochemical, morphological, and coupled ionic‐electronic transport properties. It is found that the highly twisted scaffold in d‐gdiPDI, compared to the nearly planar one of t‐gdiPDI, has a strong positive effect on the charge storage properties and thus the performance of organic electrochemical transistors (OECTs). d‐gdiPDI exhibits a volumetric capacitance of 657 F cm−3, obviously outperforming that of t‐gdiPDI (261 F cm−3), which is the highest value reported to date for small‐molecule OECT materials. Moreover, a high charge‐storage capacity of up to 479 F g−1 is observed for d‐gdiPDI. Arising from such high ionic‐electronic coupling characteristic, d‐gdiPDI‐based OECTs present a ≈2 × times higher geometry‐normalized transconductance (gm,norm) of 105.3 mS cm−1 relative to that of t‐gdiPDI counterparts. Significantly, further application of d‐gdiPDI in solid‐electrolyte OECTs delivers a gm,norm of 142.4 mS cm−1. These findings indicate that IPAHs are very promising candidates for n‐type small‐molecule OECTs and highlight the superiority of twisting conformation manipulation in materials design toward high‐performance electrochemical devices. [ABSTRACT FROM AUTHOR]

Developing new polymerized small molecular acceptor (PSMA) is pivotal for improving the performance of all‐polymer solar cells. On the basis of this newly developed CH‐series small molecule acceptors, two PSMAs are reported herein (namely PZC16 and PZC17, respectively). To reduce the molecular torsion caused by the traditional aromatic π‐bridges, non‐aromatic conjugated units (ethynyl for PZC16 and vinylene for PZC17) are adopted as the linkers and their effect on the photo‐physical properties as well as the device performance are systematically investigated. Both polymer acceptors exhibit co‐planar molecular conformation, along with broad absorption ranges and suitable energy levels. In comparison with the PM6:PZC16 film, the PM6:PZC17 film exhibits more uniform phase separation in morphology with a distinct bi‐continuous network and better crystallinity. The PM6:PZC17‐binary‐based devices exhibit a satisfactory PCE of 16.33%, significantly higher than 9.22% of the PZC16‐based devices. Impressively, PM6:PZC17‐based large area device (ca. 1 cm2) achieves an excellent PCE of 15.14%, which is among the top performance for reported all‐polymer solar cells (all‐PSCs). [ABSTRACT FROM AUTHOR]

A novel 7a,8,10,11‐tetrahydro‐9H‐pyrido[2′,1′:2,3][1,3]‐oxazino[6,5,4‐ij]isoquinoline derivative (POIQ) is accidentally obtained from an isoquinoline derivative and iodine in dimethyl sulfoxide, which is demonstrated to undergo a mechanism of demethylation and thus intramolecular nucleophilic substitution. POIQ with twisted molecular conformation and loose stacking arrangement shows multifunctional optical properties including dual‐state emission, mechanochromic, and solid‐state acidochromic activities. Furthermore, an organic room temperature phosphorescence (RTP) doped system with green afterglow of 2 s is constructed using POIQ as the guest and easily available phenyl benzoate as the host, in which the host molecules assist in the transfer of the triplet excitons of the guest molecules. Rewritable optical recording media and information encryption are also realized based on multifunctional optical properties of this compound. This work provides inspiration for the development of N,O‐containing fused‐ring compounds with fluorescence/RTP properties. [ABSTRACT FROM AUTHOR]