Inhibition of TICT can significantly increase the brightness of fluorescent materials. Accurate prediction of TICT is thus critical for the quantitative design of high‐performance fluorophores and ...AIEgens. TICT of 14 types of popular organic fluorophores were modeled with time‐dependent density functional theory (TD‐DFT). A reliable and generalizable computational approach for modeling TICT formations was established. To demonstrate the prediction power of our approach, we quantitatively designed a boron dipyrromethene (BODIPY)‐based AIEgen which exhibits (almost) barrierless TICT rotations in monomers. Subsequent experiments validated our molecular design and showed that the aggregation of this compound turns on bright emissions with ca. 27‐fold fluorescence enhancement, as TICT formation is inhibited in molecular aggregates.
A generalizable and reliable computational approach is formulated for modeling the twisted intramolecular charge transfer. Applying this approach in combination with experimental validations, azetidinyl‐substituted PRODAN and BODIPY derivatives were designed for bioimaging and aggregation‐induced emission (AIE) applications with enhanced performance.
Present one‐step N2 fixation is impeded by tough activation of the N≡N bond and low selectivity to NH3. Here we report fixation of N2‐to‐NH3 can be decoupled to a two‐step process with one problem ...effectively solved in each step, including: 1) facile activation of N2 to NOx− by a non‐thermal plasma technique, and 2) highly selective conversion of NOx− to NH3 by electrocatalytic reduction. Importantly, this process uses air and water as low‐cost raw materials for scalable ammonia production under ambient conditions. For NOx− reduction to NH3, we present a surface boron‐rich core–shell nickel boride electrocatalyst. The surface boron‐rich feature is the key to boosting activity, selectivity, and stability via enhanced NOx− adsorption, and suppression of hydrogen evolution and surface Ni oxidation. A significant ammonia production of 198.3 μmol cm−2 h−1 was achieved, together with nearly 100 % Faradaic efficiency.
A two‐step process, serially integrating non‐thermal plasma technique for facile N2 to NOx− and electrocatalytic reduction for highly selective conversion of NOx− to NH3, is presented. A surface boron‐rich nickel boride electrocatalyst was developed to boost the activity, selectivity, and stability for nitrate reduction to NH3 with nearly 100 % Faradaic efficiency and low overpotential.
•The two-photon (TP) photosensitizers (PS) of maximum absorption at 808 nm and maximum fluorescence at 660 nm can be potential for deep-seated tumor imaging and therapy.•The boron dipyrromethene ...(BDP) structure used in TP photodynamic therapy (PDT) possess favorable photophysical property (i.e., high molar extinction coefficients, superior fluorescent quantum yields, outstanding photo stability), and the indo-BDP in meso-position can efficiently improve the singlet oxygen quantum yield (0.39).•The cationic group in TP PS can efficiently improve the PDT efficacy (IC50=25.5 nM) compared with two neutral contrastive molecules (PG-Car-BDP and C10-Car-BDP).•The cationic PS TP-Car-BDP can efficiently target to tumor in vivo due to the structure inherent targeting.
Two-photon (TP) have been innovatively researched in bio-imaging and photodynamic therapy (PDT) due to the near-infread (NIR) absorption and excellent spatial accuracy, especially for the subcutaneous and deep-seated tumor. For TP excited photosensitizers (PS), the NIR absorption and enough triplet state energy can be simultaneously realized by semi-excited mode. Thus, we reported a boron dipyrromethene based cationic two-photon photosensitizer (TP-Car-BDP) to promote the tumor targeting and optical physical properties for better imaging and therapeutic effect, using two neutral molecules (PG-Car-BDP, C10-Car-BDP) as comparison. As expected, the cationic group could accelerate oil-water balance and cellular uptake, realize structure-inherent targeting in vivo, and induced early apoptosis in PDT. The imaging and therapeutic property of TP-Car-BDP excited by one/two-photon was also compared to illustrate efficacy of TP. Moreover, the high singlet oxygen quantum yield (0.39) and excellent phototoxicity (IC50 of 25.5 nM, MB was 2960 nM) revealed the potential therapeutic capacity.
At the atomic-cluster scale, pure boron is markedly similar to carbon, forming simple planar molecules and cage-like fullerenes. Theoretical studies predict that two-dimensional (2D) boron sheets ...will adopt an atomic configuration similar to that of boron atomic clusters. We synthesized atomically thin, crystalline 2D boron sheets (i.e., borophene) on silver surfaces under ultrahigh-vacuum conditions. Atomic-scale characterization, supported by theoretical calculations, revealed structures reminiscent of fused boron clusters with multiple scales of anisotropic, out-of-plane buckling. Unlike bulk boron allotropes, borophene shows metallic characteristics that are consistent with predictions of a highly anisotropic, 2D metal.
In this work, boron and nitrogen co-doped hierarchical porous carbon (BN-HPC) with a relatively high contents of boron (3.97 wt%) and nitrogen (12.10 wt%) is synthesized by a method combined with ...template process and carbonization of hierarchical porous resin using melamine and boric acid as nitrogen and boron sources, respectively. The co-doping method achieves a high boron doping level (8 times of that of single boron doped sample) which is of great significance in increasing the doping efficiency of boron. The hierarchical porosity, structure and surface chemical properties are studied in detail via various means, such as Transmission Electron Microscopy, N2 sorption, X-ray diffraction, X-ray photoelectron spectroscopy and elemental analysis, etc. Owing to the synergistic effect of hierarchical porosity and heteroatoms doping, BN-HPC exhibits greatly improved electrochemical capacitive performance of 304 F g−1 at a current density of 0.1 A g−1 and good rate capability (189 F g−1 remained at a current density of 10 A g−1). The strategy of synthesis is facile and very effective.
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For many years, organoboron compounds have been expected to show excellent electron-injecting and -transporting properties. However, lowest unoccupied molecular orbital (LUMO) energy levels (E LUMO) ...of B-containing π-conjugated molecules are mostly higher than −4.0 eV and their electron mobilities are usually less than 10–2 cm2 V–1 s–1. In this work, we experimentally prove the remarkably high electron affinity and high electron mobility of organoboron compounds. Our strategy is to incorporate multiple boron–nitrogen coordination bonds (B←N) into azaacenes. We synthesized quadruply B←N-fused dibenzo-azaacene (QBNA) through one-pot multifold borylation cyclization reaction. The incorporation of four B←N units greatly changes the electronic structures and properties and significantly downshifts the electronic energy levels of QBNA. QBNA shows a E LUMO of as low as −4.58 eV, which is among the lowest for n-type organic semiconductors. Single-crystal organic field-effect transistors of QBNA display unipolar n-type characteristic with an electron mobility of up to 1.60 cm2 V–1 s–1 together with excellent ambient stability. This study thus provides a design strategy for high-performance n-type organic semiconductors and high electron-affinity π-systems based on organoboron chemistry.
Photochemical reactions at lower energy than the absorption window are currently achieved by multi-photon processes, including two-photon absorption and photon upconversion, which have limited energy ...utilization efficiency. Here, we report a one-photon strategy based on triplet–triplet energy transfer (TTET) between a photosensitizer and a photocleavable molecule to achieve photolysis at low energy. To verify this concept, we chose platinum(II) tetraphenyltetrabenzoporphyrin (PtTPBP) as the photosensitizer and synthesized a boron-dipyrromethene (BODIPY)-based prodrug as the photocleavable molecule. Photolysis of the prodrug is achieved by TTET upon excitation of PtTPBP at 625 nm with a photolysis quantum yield of 2.8%. Another demonstration shows an unexpected higher photolysis quantum yield than the direct excitation at 530 nm. This strategy opens a new path for achieving photolysis at long wavelengths, benefiting the applications in biological studies, photopharmacology, and photoresponsive drug delivery.
Materials research is key to enable synthetic membranes for large-scale, energy-efficient molecular separations. Materials with rigid, engineered pore structures add an additional degree of freedom ...to create advanced membranes by providing entropically moderated selectivities. Scalability - the capability to efficiently and economically pack membranes into practical modules - is a critical yet often neglected factor to take into account for membrane materials screening. In this Progress Article, we highlight continuing developments and identify future opportunities in scalable membrane materials based on these rigid features, for both gas and liquid phase applications. These advanced materials open the door to a new generation of membrane processes beyond existing materials and approaches.
New symmetric and unsymmetric B,N,B‐doped benzo4helicenes 3–6 a/b have been achieved in good yields, using a three‐step process, starting from N(tolyl)3 in a highly divergent manner (7 examples). A ...borinic acid functionalized 1,4‐B,N‐anthracene 1 was found to display unprecedented reactivity, acting as a convenient and highly effective precursor for selective formation of bromo‐substituted B,N,B‐benzo4helicenes 2 a/2 b via intramolecular borylation and sequential B−Mes bond cleavage in the presence of BBr3. Subsequent reaction of 2 a/2 b with Ar‐Li provided a highly effective toolbox for the preparation of symmetrically/unsymmetrically functionalized B,N,B‐helicenes. Their high photoluminescence quantum yields along with the small ΔEST suggest their potential as thermally activated delayed fluorescence (TADF) emitters for organic light‐emitting diodes (OLEDs).
A new and divergent intramolecular borylation method has been found to be highly effective for the synthesis of a variety of symmetrically and unsymmetrically functionalized B,N,B‐4helicenes with potential applications as thermally activated delayed fluorescence (TADF) emitters in organic light‐emitting diodes (OLEDs). EDG/EWG=electron‐donating/‐withdrawing group, Mes=Mesityl.
A hybrid transition‐metal/radical process is described that results in the addition of organozinc reagents and alkyl halides across alkenyl boron reagents in an enantioselective catalytic fashion. ...The reaction can be accomplished both intermolecularly and intramolecularly, providing useful product yields and high enantioselectivities in both manifolds.
A radical hybrid: The dicarbofunctionalization of vinylB(pin) was achieved through the use of a nickel‐based chiral catalyst. The reaction employs alkyl halide and organozinc reagents and can be accomplished with good levels of enantioselectivity in an intra‐ or intermolecular fashion.
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