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A nitrogen-rich graphdiyne (HATN-GDY) material containing electrochemical active hexaazatrinaphthylene units was successfully prepared. HATN-GDY exhibits a superior specific capacity of 2139 mA h g−1 and firm long-term stability due to the unique 2D π-conjugated structure and the large in-plane N-cavities. [ABSTRACT FROM AUTHOR]

Single-crystal polymers (SCPs) with unambiguous chemical structures at atomic-level resolutions have attracted great attention. Obtaining precise structural information of these materials is critical as it enables a deeper understanding of the potential driving forces for specific packing and long-range order, secondary interactions, and kinetic and thermodynamic factors. Such information can ultimately lead to success in controlling the synthesis or engineering of their crystal structures for targeted applications, which could have far-reaching impact. Successful synthesis of SCPs with atomic level control of the structures, especially for those with 2D and 3D architectures, is rare. In this review, we summarize the recent progress in the synthesis of SCPs, including 1D, 2D, and 3D architectures. Solution synthesis, topochemical synthesis, and extreme condition synthesis are summarized and compared. Around 70 examples of SCPs with unambiguous structure information are presented, and their synthesis methods and structural analysis are discussed. This review offers critical insights into the structure–property relationships, providing guidance for the future rational design and bottom-up synthesis of a variety of highly ordered polymers with unprecedented functions and properties. [ABSTRACT FROM AUTHOR]

A highly rigid amine-linked 3D COF was constructed from two orthogonal building blocks (spirobifluorene and bicarbazole) through a post-synthetic chemical reduction. The rigid 3D framework decreased the conformational flexibility of the amine linkages, and thus showed a fully preserved crystallinity and porosity. The amine moieties in the 3D COF afforded abundant chemisorptive sites for selectively capturing CO2. [ABSTRACT FROM AUTHOR]

The efficient synthesis of lactide with high purity is the key to poly-lactic acid (PLA) production. Here, we demonstrated a 2D COFs-based catalyst, which could convert L -lactic acid into L -lactide directly in an excellent yield (80%) under mild conditions. Similar to enzymatic catalysis in which the product selectivity is controlled by the enzyme pocket, the precision confinement effect of the highly ordered channels and adjustable structures with functional moieties of the COFs play key roles in converting the monomer to the cyclic dimer directly and avoiding oligomerization. This strategy is sharply different from the current two-stage process for synthesizing lactide. The reactions are carried out at a lower temperature and under atmospheric pressure, which reduces the energy consumption significantly. In addition, this newly developed method avoids the use of metal catalysts and meets the demands of the environmental friendly trend in chemical synthesis. Last, the functions of the emerging COFs materials as excellent heterogeneous catalysts with a confinement effect were further explored. [ABSTRACT FROM AUTHOR]

In terms of temperature sensing, rare earth ion-doped upconversion luminescent materials have many outstanding advantages, such as anti-interference, fast response, and high sensitivity. In this work, Er3+/Yb3+-doped LaGaO3 microparticles have been prepared through a high-temperature solid-phase method. The microcrystals show excellent upconversion luminescence and temperature sensing under 980 nm excitation. The maximum relative sensitivity is 1.1670 × 10−2 K−1, and the temperature deviation does not exceed 1.2 K. Moreover, an optical fiber temperature sensor has been developed based on rare earth ion-doped microcrystals. The fabricated sensing device could be used in monitoring human body temperature. Our experimental results suggest that the optical fiber temperature sensor constructed with Er3+/Yb3+ codoped LaGaO3 microcrystals has high precision and stability. The proposed sensing device has a wide range of application prospects in temperature detection. [ABSTRACT FROM AUTHOR]

The commercial application of lithium metal anodes is impeded by the uncontrollable growth of lithium dendrites and the serious volume change during the cycling process. Here we develop a high-zeta-potential h-BN-doped zinc-lithium alloy (Li-ZB) as an anode to self-drive electrokinetic effects and regulate the lithium deposition behavior to achieve high-performance lithium metal batteries. The high-zeta-potential h-BN in Li-ZB promotes electrokinetic surface conduction and electroosmosis within the porous Zn-BN framework formed after lithium stripping, which in turn greatly enhances lithium-ion transport kinetics. Uniform Zn distribution in Li-ZB enables homogenous lithium nucleation and a reduced nucleation barrier. The synergistic effect of electrokinetic effect enhanced lithium-ion transport and regulated lithium nucleation behavior effectively suppresses lithium dendrite growth and mitigates the volume change issue at high deposition capacities (8 mA h cm−2), high current densities (10 mA cm−2), and a high rate (5C). The Li-ZB‖LiNi0.8Co0.1Mn0.1O2 full cells exhibit excellent cycling stability and capacity retention, as well as significantly enhanced CE, even under lean-electrolyte conditions (e.g., 3 μL mA h−1). The designed Li-ZB anodes show great potential application for next-generation lithium metal batteries with high energy density. [ABSTRACT FROM AUTHOR]

Two single-crystal structures of cucurbit[n]uril mediated supramolecular complexes were obtained in which [1+3] and [2+3] self-assembly modes are adopted due to the different sizes of cucurbit[7]uril and cucurbit[8]uril. An obvious red-shift in absorption and emission was observed compared to the guest molecule itself which makes them good biolabels. [ABSTRACT FROM AUTHOR]

Inspired by the tessellation or tiling process in daily life, a rigid triangular macrocyclic molecule containing anthracene as a photo-active moiety was synthesized to realize pre-organization through π–π interactions. The successful preparation of a 2D polymer monolayer at the air/water interface was achieved through [4+4]-photocycloaddition. [ABSTRACT FROM AUTHOR]

A co-crystal was obtained based on donor–acceptor interactions. The obvious charge transfer from the linear donor to the triangular acceptor units results in a quasi-two-dimensional CT complex with excellent near-infrared photothermal conversion efficiency. The co-crystals further acted as an excellent photothermal material in seawater desalination. [ABSTRACT FROM AUTHOR]

A well-defined crystalline cyano-functionalized graphdiyne (CN-GDY) is synthesized at a liquid/liquid interface through alkyne–alkyne coupling reactions. The configurations and nanostructures of CN-GDY were well characterized by TEM, SEM, AFM, XPS, and Raman spectroscopy. HR-TEM and selected area electron diffraction (SAED) in combination with structure simulation firmly revealed a 9-fold stacking mode for CN-GDY. [ABSTRACT FROM AUTHOR]

A series of sulfide and sulfone substituted perylene diimides (PDIs) with different LUMO levels covering a range of 0.72 eV were synthesized through simple sulfur redox chemistry. The LUMO level of phenylsulfone substituted PDI reached a record-breaking −4.75 eV. In addition, the maximum emission ranged from 540 to 692 nm. [ABSTRACT FROM AUTHOR]

A water-soluble two-dimensional supramolecular organic framework (2D SOF) was prepared via self-assembly of cucurbit[8]uril (CB[8]) and a three-arm flat linker molecule, which contains a benzene ring as the core and three Brooker's merocyanine (BM) analogs as arms. The strong host–guest interactions between BM and CB[8] and the directional head-to-tail stacking modes between the BM arms synergistically led to the formation of a 2D SOF. The structure of the 2D SOF was verified by 1H NMR, 2D 1H NMR NOESY, and DLS characterizations, while the monolayer structure was characterized by Cryo-TEM and AFM measurements. The 2D SOF exhibited an obvious AIE enhancement effect in H2O. In addition, DNA induced photoluminescence enhancement was observed for the monomer. As a result, this AIEgen-based 2D SOF could feature not only as a cell visualizer but also as a tracker for the nucleus in biological imaging due to the dynamic assembly process. [ABSTRACT FROM AUTHOR]

The spin–orbit charge transfer intersystem crossing (SOCT-ISC) of perylenemonoimide–phenothiazine compact dyads was shown to depend on the molecular geometry and the vector dipole orientations of the two chromophores, and the dyads show high triplet state quantum yields (57%). [ABSTRACT FROM AUTHOR]

Os(ii) complexes are particularly interesting for triplet–triplet annihilation (TTA) upconversion, due to the strong direct S0→ T1 photoexcitation, as in this way, energy loss is minimized and large anti-Stokes shift can be achieved for TTA upconversion. However, Os(bpy)3 has an intrinsic short T1 state lifetime (56 ns), which is detrimental for the intermolecular triplet–triplet energy transfer (TTET), one of the crucial steps in TTA upconversion. In order to prolong the triplet state lifetime, we prepared an Os(ii) tris(bpy) complex with a Bodipy moiety attached, so that an extended T1 state lifetime is achieved by excited state electronic configuration mixing or triplet state equilibrium between the coordination center-localized state (3MLCT state) and Bodipy ligand-localized state (3IL state). With steady-state and time-resolved transient absorption/emission spectroscopy, we proved that the 3MLCT is slightly above the 3IL state (by 0.05 eV), and the triplet state lifetime was prolonged by 31-fold (from 56 ns to 1.73 μs). The TTA upconversion quantum yield was increased by 4-fold as compared to that of the unsubstituted Os(ii) complex. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis of Na2Ta2O6/Ag heterojunctions with the aim of tailoring their structural, electronic and photocatalytic properties. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, UV-vis optical diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The effects of silver doping and heterojunctions on the electronic structure and photodegradation of a rhodamine B dye solution were investigated experimentally and theoretically. It was found that silver played critical roles in modulating the electronic structure, defect chemistry and visible light photocatalytic activity. Partial incorporation of Ag ions into the Na2Ta2O6 host lattice led to a monotonous lattice expansion and introduced an interband for band gap narrowing. Meanwhile, some of the Ag ions were reduced, and crystallized into Ag nanoparticles on Na2Ta2O6 surfaces that can promote the visible light absorption efficiency of Na2Ta2O6/Ag heterojunctions. Moreover, the doping and heterojunction of silver can also result in the modulation of defective oxygen species that have a great impact on photocatalytic performance. As a consequence of the well-controlled electronic structure, surface defect chemistry, Ag particle size, BET surface area, and Ag+ doping effects, the photocatalytic performance of the Na2Ta2O6/Ag heterojunctions was optimized at an as-measured Ag/Ta molar ratio of 1.17. [ABSTRACT FROM AUTHOR]

Two supramolecular complexes were prepared using cucurbiturils [CBs] as mediators and a four-armed p -xylene derivative (M1) as a guest molecule. The single crystals of these two complexes were obtained and successfully analyzed by single-crystal X-ray diffraction (SCXRD). An unexpected and intriguing 1 : 2 self-assembly arrangement between M1 and CB[8] was notably uncovered, marking its first observation. These host-guest complexes exhibit distinctive photophysical properties, especially emission behaviors. Invaluable insights can be derived from these single-crystal structures. The precious single-crystal structures provide both precise structural information regarding the supramolecular complexes and a deeper understanding of the intricate mechanisms governing their photophysical properties., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

We report a facile surface-induced method for the in situ growth of single-/few-layered crystalline fluorographdiyne film on the surface of carbon fibers (cFGDY). The crystallized structure of cFGDY was directly confirmed by the scanning/transmission electron microscopy (SEM/TEM), high-resolution TEM (HRTEM) and computer simulation, selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. cFGDY showed a 9-fold stacking mode. Our results show that cFGDY is a metal-free electrocatalyst with unique structure and excellent performance for ammonia production from nitrogen and water efficiently at room temperature and ambient pressure, achieving a high NH 3 production rate and Faraday efficiency in neutral conditions. This work provides an efficient catalyst system with determined chemical and electronic structures for highly selective and active nitrogen reduction, serving as a promising platform towards the development of novel metal-free catalysts.

In nature, spectacular function is achieved by highly sophisticated supramolecular architectures. Little is known what we would obtain if we could create complexity with similar precision, because the synthetic methods to do so are not available. This account summarizes recent approaches conceived to improve on this situation. With self-organizing surface-initiated polymerization (SOSIP), charge-transporting stacks can be grown directly on solid substrates with molecular-level precision. The extension to templated self-sorting (SOSIP-TSS) offers a supramolecular approach to multicomponent architectures. A solid theoretical framework for the transcription of information by templated self-sorting has been introduced, intrinsic templation efficiencies up to 97% have been achieved, and the existence of self-repair has been shown. The extension to templated stack exchange (SOSIP-TSE) offers the complementary covalent approach. Compatibility of this robust method with the creation of double-channel architectures with antiparallel two-component gradients has been demonstrated.

s-Tetrazine and their derivatives are found to be a class of selective and colorimetric chemosensors for fluoride anions. The supramolecular interaction (anion-π and charge/electron transfer) between fluoride ion and π-electron deficient tetrazines receptor could facilitate the F(-)-tetrazines electron transfer (ET) event that generates tetrazine˙(-) radical anion. Accordingly, the color of its solution changed from red to green. Furthermore, the recognition of F(-) in DMSO is tolerant to water (DMSO-H(2)O = 9:1, v/v) and shows excellent selectivity towards other anions, especially H(2)PO(4)(-) and OAc(-).

A rotaxane incorporating three different stations and fluorescent states (output) was prepared. The movement of the macrocycle can be easily detected by fluorescence change as an output signal and the macrocycle could be easily controlled to locate on three different stations of the thread by the tuning of acid/base (input).

A successful approach for the synthesis of indolocarbazole-containing macrocycles based upon pi-pi stacking preorganization of indolocarbazole planes and click-chemistry reactions has been developed. The macrocycles are able to form folded structures with the help of hydrogen-bonding and pi-pi stacking interactions. Two of the receptors were successfully characterized by single-crystal X-ray diffraction analysis. Our results confirmed that they showed different interesting self-assembly with the anions due to the N-H...X(-) and the triazole C-H...X(-) hydrogen-bonding.

The construction of an interpenetrated structure of macrocycles by a CuAAC "click" reaction was achieved and the binding selectivity of indolocarbazole for a chloride anion was enhanced upon catenanation.