•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.
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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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.
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.
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.
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.
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.
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.
Since their discovery in 2005, covalent organic frameworks (COFs) have attracted interest as potential materials for gas storage, catalysis, energy storage, and other applications because of their ...ability to periodically and reliably organize designed functionality into high surface area materials. Most of the first examples relied on boron-containing linkages, which suffer from hydrolytic and oxidative instability that limit their utility. In this Perspective, we describe the trend toward more robust linkages by highlighting the design, synthesis, and properties of several recent examples. The continued development of new COF chemistries, along with improved understanding of their formation and control of their final form, will provide a means to harness their molecularly precise solid-state structures for useful purposes.
Dodecaborate anions of the type B12X122- and B12X11Y2- (X=H, Cl, Br, I and Y=OH, SH, NH3+, NR3+) form strong (Ka up to 106Lmol-1, for B12Br122-) inclusion complexes with gamma-cyclodextrin ...(gamma-CD). The micromolar affinities reached are the highest known for this native CD. The complexation exhibits highly negative enthalpies (up to -25kcalmol-1) and entropies (TDeltaS up to -18.4kcalmol-1, both for B12I122-), which position these guests at the bottom end of the well-known enthalpy-entropy correlation for CDs. The high driving force can be traced back to a chaotropic effect, according to which chaotropic anions have an intrinsic affinity to hydrophobic cavities in aqueous solution. In line with this argument, salting-in effects revealed dodecaborates as superchaotropic dianions.
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