Boosting the Ultrastable High-Na-Content P2-type Layered Cathode Materials with Zero-Strain Cation Storage via a Lithium Dual-Site Substitution Approach.

P2-type layered transition-metal (TM) oxides, NaxTMO2, are highly promising as cathode materials for sodium-ion batteries (SIBs) due to their excellent rate capability and affordability. However, P2-type NaxTMO2 is afflicted by issues such as Na+/vacancy ordering and multiple phase transitions during Na-extraction/insertion, leading to staircase-like voltage profiles. In this study, we employ a combination of high Na content and Li dual-site substitution strategies to enhance the structural stability of a P2-type layered oxide (Na0.80Li0.024[Li0.065Ni0.22Mn0.66]O2). The experimental results reveal that these approaches facilitate the oxidation of Mn ions to a higher valence state, thereby affecting the local environment of both TM and Na ions. The resulting modification in the local structure significantly improves the Na-ion storage capabilities as required for cathode materials in SIBs. Furthermore, it induces a solid-solution reaction and enables nearly zero-strain operation (ΔV = 0.7%) in the Na0.80Li0.024[Li0.065Ni0.22Mn0.66]O2 cathode during cycling. The assembled full cells demonstrate an exceptional rate performance, with a retention rate of 87% at 10 C compared to that of 0.1 C, as well as an ultrastable cycling capability, maintaining a capacity retention of 73% at 2 C after 1000 cycles. These findings offer valuable insights into the electronic and structural chemistry of ultrastable cathode materials with "zero-strain" Na-ion storage.

Time-dependent photo-activated aminoborane room-temperature phosphorescence materials with unprecedented properties: simple, versatile, multicolor-tuneable, water resistance, optical information writing/erasing, and multilevel data encryption.

Triarylboranes-based pure organic room-temperature phosphorescence (RTP) materials are rarely investigated because of their large steric hindrance and the electron defect of the boron atom. As a result, creating functional triarylborane RTP materials is difficult. Herein, we report the first photo-activated RTP materials with lifetimes/quantum yields ≤0.18 s/6.83% based on donor (D)-π-acceptor (A) from methylene carbazole-functionalized aminoborane (BN)-doped polymethyl methacrylate (BN-o-Met-Cz@PMMA) under 365 nm UV irradiation (30 s). Incredibly, BN-o-Met-Cz@PMMA films exhibited unprecedented photo-activated RTP dual-response properties (e.g., air + 365 nm: τ P = 0.18 s, Φ P = 6.83%; N2 + 365 nm: τ P = 0.42 s, Φ P = 17.34%). Intriguingly, the BN (D-π-A) system demonstrated good versatility for photo-activated RTP whether the electron-donating group or electron-withdrawing group was placed in the ortho (meta)-position of the B atom. As a result, a series of photo-activated single-molecule organic RTP materials with multi-color emission, high quantum yields, and ultra-long lifetimes can be prepared rapidly. BN-X@PMMA films showed broad application prospects for information encryption, data erasure, anti-counterfeiting, and water resistance. Our method provides new strategies for the design, synthesis, and application of RTP materials, thereby enriching the types of organic RTP materials and facilitating further developments in this area.

Multiple Helicenes Defected by Heteroatoms and Heptagons with Narrow Emissions and Superior Photoluminescence Quantum Yields.

The incorporation of heteroatoms and/or heptagons as the defects into helicenes expands the variety of chiroptical materials with novel properties. However, it is still challenging to construct novel boron-doped heptagon-containing helicenes with high photoluminescence quantum yields (PLQYs) and narrow full-width-at-half-maximum (FWHM) values. We report an efficient and scalable synthesis of a quadruple helicene 4Cz-NBN with two nitrogen-boron-nitrogen (NBN) units and a double helicene 4Cz-NBN-P1 bearing two NBN-doped heptagons, the latter could be formed via a two-fold Scholl reaction of the former. The helicenes 4Cz-NBN and 4Cz-NBN-P1 exhibit excellent PLQYs up to 99 % and 65 % with narrow FWHM of 24 nm and 22 nm, respectively. The emission wavelengths are tunable via stepwise titration experiments of 4Cz-NBN-P1 toward fluoride, enabling distinguished circularly polarized luminescence (CPL) from green, orange (4Cz-NBN-P1-F1) to yellow (trans/cis-4Cz-NBN-P1-F2) with near-unity PLQYs and broader circular dichroism (CD) ranges. The five structures of the aforementioned four helicenes were confirmed by single crystal X-ray diffraction analysis. This work provides a novel design strategy for construction of non-benzenoid multiple helicenes exhibiting narrow emissions with superior PLQYs.

Accumulated Lattice Strain as an Intrinsic Trigger for the First-Cycle Voltage Decay in Li-Rich 3d Layered Oxides.

Li- and Mn-rich layered oxides (LMLOs) are promising cathode materials for Li-ion batteries (LIBs) owing to their high discharge capacity of above 250 mA h g-1. A high voltage plateau related to the oxidation of lattice oxygen appears upon the first charge, but it cannot be recovered during discharge, resulting in the so-called voltage decay. Disappearance of the honeycomb superstructure of the layered structure at a slow C-rate (e.g., 0.1 C) has been proposed to cause the first-cycle voltage decay. By comparing the structural evolution of Li[Li0.2Ni0.2Mn0.6]O2 (LLNMO) at various current densities, the operando synchrotron-based X-ray diffraction results show that the lattice strain in bulk LLNMO is continuously increased over cycling, resulting in the first-cycle voltage loss upon Li-ion insertion. Unlike the LLNMO, the accumulated average lattice strain of LiNi0.8Co0.1Mn0.1O2 (NCM811) and LiNi0.6Co0.2Mn0.2O2 (NCM622) from the open-circuit voltage to 4.8 V could be released on discharge. These findings help to gain a deep understanding of the voltage decay in LMLOs.

Long-Range Cationic Disordering Induces two Distinct Degradation Pathways in Co-Free Ni-Rich Layered Cathodes.

Ni-rich layered oxides are one of the most attractive cathode materials in high-energy-density lithium-ion batteries, their degradation mechanisms are still not completely elucidated. Herein, we report a strong dependence of degradation pathways on the long-range cationic disordering of Co-free Ni-rich Li1-m (Ni0.94 Al0.06 )1+m O2 (NA). Interestingly, a disordered layered phase with lattice mismatch can be easily formed in the near-surface region of NA particles with very low cation disorder (NA-LCD, m≤0.06) over electrochemical cycling, while the layered structure is basically maintained in the core of particles forming a "core-shell" structure. Such surface reconstruction triggers a rapid capacity decay during the first 100 cycles between 2.7 and 4.3 V at 1 C or 3 C. On the contrary, the local lattice distortions are gradually accumulated throughout the whole NA particles with higher degrees of cation disorder (NA-HCD, 0.06≤m≤0.15) that lead to a slow capacity decay upon cycling.

Zur and zinc increase expression of E. coli ribosomal protein L31 through RNA-mediated repression of the repressor L31p.

Bacteria can adapt in response to numerous stress conditions. One such stress condition is zinc depletion. The zinc-sensing transcription factor Zur regulates the way numerous bacterial species respond to severe changes in zinc availability. Under zinc sufficient conditions, Zn-loaded Zur (Zn2-Zur) is well-known to repress transcription of genes encoding zinc uptake transporters and paralogues of a few ribosomal proteins. Here, we report the discovery and mechanistic basis for the ability of Zur to up-regulate expression of the ribosomal protein L31 in response to zinc in E. coli. Through genetic mutations and reporter gene assays, we find that Zur achieves the up-regulation of L31 through a double repression cascade by which Zur first represses the transcription of L31p, a zinc-lacking paralogue of L31, which in turn represses the translation of L31. Mutational analyses show that translational repression by L31p requires an RNA hairpin structure within the l31 mRNA and involves the N-terminus of the L31p protein. This work uncovers a new genetic network that allows bacteria to respond to host-induced nutrient limiting conditions through a sophisticated ribosomal protein switching mechanism.

Current strategies employed in the manipulation of gene expression for clinical purposes.

Abnormal gene expression level or expression of genes containing deleterious mutations are two of the main determinants which lead to genetic disease. To obtain a therapeutic effect and thus to cure genetic diseases, it is crucial to regulate the host's gene expression and restore it to physiological conditions. With this purpose, several molecular tools have been developed and are currently tested in clinical trials. Genome editing nucleases are a class of molecular tools routinely used in laboratories to rewire host's gene expression. Genome editing nucleases include different categories of enzymes: meganucleses (MNs), zinc finger nucleases (ZFNs), clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR associated protein (Cas) and transcription activator-like effector nuclease (TALENs). Transposable elements are also a category of molecular tools which includes different members, for example Sleeping Beauty (SB), PiggyBac (PB), Tol2 and TcBuster. Transposons have been used for genetic studies and can serve as gene delivery tools. Molecular tools to rewire host's gene expression also include episomes, which are divided into different categories depending on their molecular structure. Finally, RNA interference is commonly used to regulate gene expression through the administration of small interfering RNA (siRNA), short hairpin RNA (shRNA) and bi-functional shRNA molecules. In this review, we will describe the different molecular tools that can be used to regulate gene expression and discuss their potential for clinical applications. These molecular tools are delivered into the host's cells in the form of DNA, RNA or protein using vectors that can be grouped into physical or biochemical categories. In this review we will also illustrate the different types of payloads that can be used, and we will discuss recent developments in viral and non-viral vector technology.

Microfluidic generation of multifunctional core-shell microfibers promote wound healing.

Wound healing is a complex physiological process involving four coordinated stages, including hemostasis, anti-inflammatory, repair, and epithelial formation. Herein, multifunctional core-shell alkylated chitosan/calcium alginate microfibers are fabricated as a novel strategy for promoting wound healing by contributing to each four stages in the entire healing process. Taking advantages of the microfluidic technology, the core-shell microfibers can be generated in a continuous and convenient manner through the interfacial assembly between alkylated chitosan and Na-alginate, as well as the simultaneous crosslink between calcium and the alginate. Generated microfibers possess unique internal structure which can effectively promote the absorption of blood and exudate produced during trauma. Moreover, the dodecyl carbon chain and abundant amino groups of alkylated chitosan provide microfibers with excellent hemostatic and antibacterial properties, which can repair acute hemorrhage and destroy bacteria rapidly. Further, the chronic wound healing process of a skin injury model can be significantly promoted by applying the fabricated microfibers. With these sequential functions to guide the whole-stage wound healing, the presented multifunctional core-shell microfibers create a versatile and robust paradigm for comprehensive wound treatment.

Enhanced Electrochemiluminescence of A Macrocyclic Tetradentate Chelate Pt(II) Molecule through Its Collisional Interactions with the Electrode.

A macrocyclic tetradentate chelate Pt(II) molecule (Pt1) served as an excellent luminophore in electrochemiluminescence (ECL) processes. The blue ECL of Pt1/S2 O8 2- coreactant system in N,N'-dimethylformamide was found to be 46 times higher than that of the Ru(bpy)2+ /S2 O8 2- system or 30 times higher than that of the 9,10-diphenylanthracene/S2 O8 2- system. The unprecedented high ECL quantum efficiencies were caused by the cyclic generation of monomer excited states through collisional interactions of Pt1 molecules with the electrode at an elevated frequency. The ECL is tunable from bright blue to pure white by simply changing the solvent from N,N'-dimethylformamide to dichloromethane. The white ECL of Pt(II) molecule was reported for the first time and the mechanism was proposed to be the simultaneous emissions from the monomer excited state (blue) and excimer (red).

Efficient epidermal delivery of antibiotics by self-assembled lecithin/chitosan nanoparticles for enhanced therapy on epidermal bacterial infections.

The treatment for epidermal bacterial infections has become a primary healthy concern, producing a significant therapeutic challenge. Here we present a facile strategy to fabricate lecithin/chitosan nanoparticles (LCNPs) for efficient epidermal drug delivery over epidermal bacterial infections. The central rotatable composite design method was used for the optimization of the preparation, and that the optimal size (212.63 ± 1.95 nm) was obtained via analysis of variance (ANOVA). The prepared CIP-LCNPs show an average diameter of 325.9 ± 7.4 nm and a zeta potential of 26.6 ± 1.2 mV. Antibiotics can be well encapsulated in LCNPs and its release kinetics is studied with cumulative release of 93.81 ± 2.05 % for 48 h. The hemolytic activity, cytotoxicity, and skin irritation are further investigated. The zones of inhibition are 2.16 ± 0.04 cm and 2.92 ± 0.03 cm for Escherichia coli and Staphylococcus aureus, respectively. Moreover, in vitro permeation studies demonstrate that LCNPs can increase the accumulation of antibiotics in the epidermis with retention ratio 2-3 fold higher than commercial formulations. The in vivo result over epidermal-infected wound demonstrates the superior therapeutic effects of LCNPs. The developed LCNPs represent an important advance in fabricating therapeutic materials for enhanced therapy over epidermal bacterial infections.

Structural Origin of Suppressed Voltage Decay in Single-Crystalline Li-Rich Layered Li[Li0.2 Ni0.2 Mn0.6 ]O2 Cathodes.

Lithium- and manganese-rich layered oxides (LMLOs, ≥ 250 mAh g-1 ) with polycrystalline morphology always suffer from severe voltage decay upon cycling because of the anisotropic lattice strain and oxygen release induced chemo-mechanical breakdown. Herein, a Co-free single-crystalline LMLO, that is, Li[Li0.2 Ni0.2 Mn0.6 ]O2 (LLNMO-SC), is prepared via a Li+ /Na+ ion-exchange reaction. In situ synchrotron-based X-ray diffraction (sXRD) results demonstrate that relatively small changes in lattice parameters and reduced average micro-strain are observed in LLNMO-SC compared to its polycrystalline counterpart (LLNMO-PC) during the charge-discharge process. Specifically, the as-synthesized LLNMO-SC exhibits a unit cell volume change as low as 1.1% during electrochemical cycling. Such low strain characteristics ensure a stable framework for Li-ion insertion/extraction, which considerably enhances the structural stability of LLNMO during long-term cycling. Due to these peculiar benefits, the average discharge voltage of LLNMO-SC decreases by only ≈0.2 V after 100 cycles at 28 mA g-1 between 2.0 and 4.8 V, which is much lower than that of LLNMO-PC (≈0.5 V). Such a single-crystalline strategy offers a promising solution to constructing stable high-energy lithium-ion batteries (LIBs).

Association Between Platelet Levels and 28-Day Mortality in Patients With Sepsis: A Retrospective Analysis of a Large Clinical Database MIMIC-IV.

Background: This research focused on evaluating the correlation between platelet count and sepsis prognosis, and even the dose-response relationship, in a cohort of American adults. Method: Platelet counts were recorded retrospectively after hospitalization for patients admitted to Beth Israel Deaconess Medical Center's intensive care unit between 2008 and 2019. On admission to the intensive care unit, sepsis patients were divided into four categories based on platelet counts (very low < 50 × 109/L, intermediate-low 50 × 109-100 × 109/L, low 100 × 109-150 × 109/L, and normal ≥ 150 × 109/L). A multivariate Cox proportional risk model was used to calculate the 28-day risk of mortality in sepsis based on baseline platelet counts, and a two-piece linear regression model was used to calculate the threshold effect. Results: The risk of 28-day septic mortality was nearly 2-fold higher in the platelet very low group when compared to the low group (hazard ratios [HRs], 2.24; 95% confidence interval [CI], 1.92-2.6). Further analysis revealed a curvilinear association between platelets and the sepsis risk of death, with a saturation effect predicted at 100 × 109/L. When platelet counts were below 100 × 109/L, the risk of sepsis 28-day death decreased significantly with increasing platelet count levels (HR, 0.875; 95% CI, 0.84-0.90). Conclusion: When platelet count was less than 100 × 109/L, it was a strong predictor of the potential risk of sepsis death, which is declined by 13% for every 10 × 109/L growth in platelets. When platelet counts reach up to 100 × 109/L, the probability of dying to sepsis within 28 days climbs by 1% for every 10 × 109/L increase in platelet count.

Multi-resonant thermally activated delayed fluorescence emitters based on tetracoordinate boron-containing PAHs: colour tuning based on the nature of chelates.

Multi-resonant thermally activated delayed fluorescence (MR-TADF) materials have attracted considerable attention recently. The molecular design frequently incorporates cycloboration. However, to the best of our knowledge MR-TADF compounds containing nitrogen chelated to boron are still unknown. Reported herein is a new class of tetracoordinate boron-containing MR-TADF emitters bearing C^N^C- and N^N^N-chelating ligands. We demonstrate that the replacement of the B-C covalent bond in the C^N^C-chelating ligand by the B-N covalent bond affords an isomer, which dramatically influences the optoelectronic properties of the molecule. The resulting N^N^N-chelating compounds show bathochromically shifted absorption and emission spectra relative to C^N^C-chelating compounds. The incorporation of a tert-butylcarbazole group at the 4-position of the pyridine significantly enhances both the thermal stability and the reverse intersystem crossing rate, yet has a negligible effect on emission properties. Consequently, high-performance hyperfluorescent organic light-emitting diodes (HF-OLEDs) that utilize these molecules as green and yellow-green emitters show a maximum external quantum efficiency (η ext) of 11.5% and 25.1%, and a suppressed efficiency roll-off with an η ext of 10.2% and 18.7% at a luminance of 1000 cd m-2, respectively.

Optimized Design Method for Pt/SiO2-Al2O3 with High NH3-SCO Activity and Thermal Stability.

Pt/SiO2-Al2O3 catalysts were prepared by the traditional impregnation method (IM) and the strong electrostatic adsorption (SEA) process. Differences in particle size, surface chemical state, Pt adsorption site, ammonia oxidation activity, and thermal stability of Pt species were studied systematically. For the fresh catalyst of Pt/SiO2-Al2O3-IM (Pt/SiO2-Al2O3-IM-fresh), Pt species were dispersed unselectively on SiO2-Al2O3, and the large average size (6.6 nm) of Pt species could be observed in a bimodal distribution (ranges of 5.5-6.5 and 8.5-9.5 nm). After the hydrothermal treatment, the Pt size of the aged catalyst (Pt/SiO2-Al2O3-IM-aged) increased significantly, especially Pt particles on SiO2 showed obvious agglomeration and some even increased to 40 nm. Conversely, for the catalyst prepared through the SEA process, Pt species of Pt/SiO2-Al2O3-SEA-fresh were selectively absorbed on Al2O3, the Pt particle size was in the range of 1.5-6.0 nm, and the average particle size was only 2.7 nm. After hydrothermal aging, Pt species did not show obvious agglomeration (the average particle size was 3.2 nm). Above all, Pt/SiO2-Al2O3-SEA presented better catalytic activity and thermal stability than Pt/SiO2-Al2O3-IM, i.e., the temperatures of 50% NH3 conversion for the fresh and aged Pt/SiO2-Al2O3-SEA catalysts were 216 and 223 °C, respectively, much lower than those for Pt/SiO2-Al2O3-IM-fresh (228 °C) and Pt/SiO2-Al2O3-IM-aged (250 °C).

Density-Dependent Emission Colors from a Conformation-Switching Chromophore in Polyurethanes.

Achieving full-color emission from a single chromophore is not only highly desirable from practical considerations, but also greatly challenging for fundamental research. Herein, we demonstrated the density-dependent emission colors from a single boron-containing chromophore, from which multi-color fluorescent polyurethanes were prepared as well. Originating from its switchable molecular conformations, the emission color of the chromophore was found to be governed by the packing density and strongly influenced by hydrogen bonding interactions. The chromophore was incorporated into polyurethanes to achieve full-color emitting materials; the emission color was only dependent on the chromophore density and could be tuned via synthetic approach by controlling the compositions. The emission colors could also be modulated by physical approaches, including by swelling/deswelling process, compression under high pressure, and even blending the fluorescent polyurethane with non-emitting ones.

Formation of an air-stable diborane via a stepwise BH3 addition of pyrido[1,2-a]isoindole with H2 evolution.

A novel and air-stable organo(hydro)diborane featuring a five-membered aryl ring supported bridging B-C-B three-centre-two-electron (3c-2e) bond has been reported. Pyrido[1,2-a]isoindole was found to undergo a stepwise BH3 addition reaction, during which a mono-BH3 adduct was formed from a electrophilic addition at the Cγ in pyrido[1,2-a]isoindole. A molecule of hydrogen was eliminated throughout the second step of addition reaction. DFT calculations indicate that the H2 evolution is concerted to the second BH3 addition rather than forming BC before the second BH3 attack.

Enhanced Electrochemical Performance of LiNi0.5Mn1.5O4 Composite Cathodes for Lithium-Ion Batteries by Selective Doping of K+/Cl- and K+/F.

K+/Cl- and K+/F- co-doped LiNi0.5Mn1.5O4 (LNMO) materials were successfully synthesized via a solid-state method. Structural characterization revealed that both K+/Cl- and K+/F- co-doping reduced the LixNi1-xO impurities and enlarged the lattice parameters compared to those of pure LNMO. Besides this, the K+/F- co-doping decreased the Mn3+ ion content, which could inhibit the Jahn-Teller distortion and was beneficial to the cycling performance. Furthermore, both the K+/Cl- and the K+/F- co-doping reduced the particle size and made the particles more uniform. The K+/Cl- co-doped particles possessed a similar octahedral structure to that of pure LNMO. In contrast, as the K+/F- co-doping amount increased, the crystal structure became a truncated octahedral shape. The Li+ diffusion coefficient calculated from the CV tests showed that both K+/Cl- and K+/F- co-doping facilitated Li+ diffusion in the LNMO. The impedance tests showed that the charge transfer resistances were reduced by the co-doping. These results indicated that both the K+/Cl- and the K+/F- co-doping stabilized the crystal structures, facilitated Li+ diffusion, modified the particle morphologies, and increased the electrochemical kinetics. Benefiting from the unique advantages of the co-doping, the K+/Cl- and K+/F- co-doped samples exhibited improved rate and cycling performances. The K+/Cl- co-doped Li0.97K0.03Ni0.5Mn1.5O3.97Cl0.03 (LNMO-KCl0.03) exhibited the best rate capability with discharge capacities of 116.1, 109.3, and 93.9 mAh g-1 at high C-rates of 5C, 7C, and 10C, respectively. Moreover, the K+/F- co-doped Li0.98K0.02Ni0.5Mn1.5O3.98F0.02 (LNMO-KF0.02) delivered excellent cycling stability, maintaining 85.8% of its initial discharge capacity after circulation for 500 cycles at 5C. Therefore, the K+/Cl- or K+/F- co-doping strategy proposed herein will play a significant role in the further construction of other high-voltage cathodes for high-energy LIBs.

Highly Emissive 9-Borafluorene Derivatives: Synthesis, Photophysical Properties and Device Fabrication.

A series of 9-borafluorene derivatives, functionalised with electron-donating groups, have been prepared. Some of these 9-borafluorene compounds exhibit strong yellowish emission in solution and in the solid state with relatively high quantum yields (up to 73.6 % for FMesB-Cz as a neat film). The results suggest that the highly twisted donor groups suppress charge transfer, but the intrinsic photophysical properties of the 9-borafluorene systems remain. The new compounds showed enhanced stability towards the atmosphere, and exhibited excellent thermal stability, revealing their potential for application in materials science. Organic light-emitting diode (OLED) devices were fabricated with two of the highly emissive compounds, and they exhibited strong yellow-greenish electroluminescence, with a maximum luminance intensity of >22 000 cd m-2 . These are the first two examples of 9-borafluorene derivatives being used as light-emitting materials in OLED devices, and they have enabled us to achieve a balance between maintaining their intrinsic properties while improving their stability.

Millisecond Time-scale Photoluminescence of B-N-doped Tetrathienonaphthalene with Borane/Amine Substituents.

BN-doped polycyclic aromatic hydrocarbons (PAHs) have attracted numerous attentions because of their fascinating optical and electronic properties. In this work, a series of electron-donor (amine)- and -acceptor (borane)-functionalized BN-doped polycyclic aromatic hydrocarbons were prepared to study the substituents' effect on the photophysical properties. As a result, the compound with both donor and acceptor, BN, exhibits both local emission (LE) and charge-transfer emission (CT) in polar solvents. Especially, the CT emission with a longer wavelength revealed a lifetime as long as millisecond time scale at room temperature, indicating typical phosphorescence characteristics. Low-temperature photoluminescent (PL) spectroscopy and a theoretical study were conducted to help to interpret this phenomenon, and it turned out to be the lowering of the S1 energy level of BN which makes the intersystem crossing favorable. Furthermore, fluoride anion titration experiments exhibit the application potential of the dual-emission phenomenon of BN for ratiometric sensory materials.

Sequential and Diverse Synthesis of BN-Heterocycles and Investigation of Their Photoreactivity.

Substituents modification of BN-heterocycles on the boron atom has proven important to the photoreactivity and optoelectronic properties of BN-heterocycles. We developed a sequential and diverse synthetic strategy toward BN-heterocycles, in which the boron building block can be introduced with fully pre-functionalized substituents (Route A) or the substituents can be partially (Route B) or fully (Route C) modified after borylation. These three routes are complementary to provide more diverse BN-heterocycles, which will find broad applications in manipulating/controlling molecular transformations and the development of new photoresponsive materials.