Iridium(III) Carbene Complexes Featuring either Metal-to-Ligand Charge Transfer (MLCT) or Through-Space Charge Transfer (TSCT) Blue Luminescence.

Through-space charge transfer (TSCT) rather than the commonly postulated metal-to-ligand charge transfer (MLCT) process was proposed in getting the lowest lying excited state of newly designed Ir(III) blue phosphors. Accordingly, two benzo[d]imidazolylidene pro-chelates L12H2+ and L13H2+, one with two cyano groups at the peri-benzo and N-aryl pendent and the other with its peri-cyano group being replaced with methyl substituent, were employed in syntheses of Ir(III) complexes f-ct12b,c and f-ct13b,c. Notably, complexes f-ct12b,c exhibited the traditional MLCT process, while f-ct13b,c were dominated by the TSCT transition, resulting in a smaller S1-T1 energy gap ΔEST.

Harnessing J-aggregation for dual-color cellular imaging with chromenoquinoline-benzimidazole dyes.

Fluorescence imaging has revolutionized the visualization of cellular structures and biomolecules due to its non-invasive nature and high sensitivity. Chromenoquinoline (CQ)-based dyes offer promising optical properties, yet their widespread application is hindered by aggregation-caused quenching (ACQ). In contrast, J-aggregates, characterized by distinctive photophysical properties, present a solution to ACQ.

Enhanced Emitting Dipole Orientation Based on Asymmetric Iridium(III) Complexes for Efficient Saturated-Blue Phosphorescent OLEDs.

Three novel asymmetric Ir(III) complexes have been rationally designed to optimize their emitting dipole orientations (EDO) and enhance light outcoupling in blue phosphorescent organic light-emitting diodes (OLEDs), thereby boosting their external quantum efficiency (EQE). Bulky electron-donating groups (EDGs), namely: carbazole (Cz), di-tert-butyl carbazole (tBuCz), and phenoxazine (Pxz) are incorporated into the tridentate dicarbene pincer chelate to induce high degree of packing anisotropy, simultaneously enhancing their photophysical properties. Angle-dependent photoluminescence (ADPL) measurements indicate increased horizontal transition dipole ratios of 0.

Integrative catalytic pairs for efficient multi-intermediate catalysis.

Single-atom catalysts (SACs) have attracted considerable research interest owing to their combined merits of homogeneous and heterogeneous catalysts. However, the uniform and isolated active sites of SACs fall short in catalysing complex chemical processes that simultaneously involve multiple intermediates. In this Review, we highlight an emerging class of catalysts with adjacent binary active centres, which is called integrative catalytic pairs (ICPs), showing not only atomic-scale site-to-site electronic interactions but also synergistic catalytic effects.

Dimethyl Dihydrophenazine: A Highly Conjugated Auxochrome in Fluorophores to Improve Photostability, Red-Shift Wavelength, and Enlarge Stokes Shift.

5,10-Dimethyl-5,10-dihydrophenazine () is utilized as an effective auxochrome, leveraging its highly conjugated structure to enhance the photophysical and photochemical properties of fluorophores. As illustrated in the difluoride-boron complex and coumarin fluorophores, the extensive conjugation of auxochrome substantially red-shifts the absorption/emission wavelengths and increases Stokes shift due to the intensified intramolecular charge transfer effect; notably, auxochrome effectively improves fluorophores' photostability by mitigating photooxidative reactions through enhanced electron density delocalization on nitrogen atoms and increased ionization potential. Importantly, MP-based fluorophores demonstrate applicability in stimulated emission depletion nanomicroscopy, showcasing their utility in lipid droplet labeling.

Tumor Microenvironment-Activatable Phototheranostic: Leveraging Nitric Oxide and Weak Acidity as Dual Biomarkers for Ratiometric Fluorescence, Photoacoustic Imaging, and Photothermal Therapy.

Tumor microenvironment-responsive phototheranostic agents are highly sought after for their ability to improve diagnostic accuracy and treatment specificity. Here, we introduce a novel single-molecule probe, , which is activated by nitric oxide (NO) and weak acidity, enabling dual-mode imaging and photothermal therapy (PTT) of tumors. In acidic environments with elevated NO levels, exhibits a distinctive ratiometric fluorescence signal shift from the red to near-infrared, accompanied by a 700 nm photoacoustic signal.

Auxochrome Dimethyl-Dihydroacridine Improves Fluorophores for Prolonged Live-Cell Super-Resolution Imaging.

Superior photostability, minimal phototoxicity, red-shifted absorption/emission wavelengths, high brightness, and an enlarged Stokes shift are essential characteristics of top-tier organic fluorophores, particularly for long-lasting super-resolution imaging in live cells (e.g., via stimulated emission depletion (STED) nanoscopy).

Bis-tridentate Ir(III) Phosphors and Blue Hyperphosphorescence with Suppressed Efficiency Roll-Off at High Brightness.

Narrowband blue emitters are indispensable in achieving ultrahigh-definition OLED displays that satisfy the stringent BT 2020 standard. Hereby, a series of bis-tridentate Ir(III) complexes bearing electron-deficient imidazo[4,5-]pyridin-2-ylidene carbene coordination fragments and 2,6-diaryloxy pyridine ancillary groups were designed and synthesized. They exhibited deep blue emission with quantum yields of up to 89% and a radiative lifetime of 0.

Deciphering the ultra-high plasticity in metal monochalcogenides.

The quest for electronic devices that offer flexibility, wearability, durability and high performance has spotlighted two-dimensional (2D) van der Waals materials as potential next-generation semiconductors. Especially noteworthy is indium selenide, which has demonstrated surprising ultra-high plasticity. To deepen our understanding of this unusual plasticity in 2D van der Waals materials and to explore inorganic plastic semiconductors, we have conducted in-depth experimental and theoretical investigations on metal monochalcogenides (MX) and transition metal dichalcogenides (MX).

Structural Engineering of Iridium(III) Phosphors with Imidazo[4,5-b]pyrazin-2-ylidene Cyclometalates for Efficient Blue Electroluminescence.

Iridium(III) complexes are particularly noted for their excellent potentials in fabrication of blue organic light-emitting diodes (OLEDs), but the severe efficiency roll-off largely hampered their practical applications. To reveal the underlying characteristics, three Ir(III) complexes, namely f-ct5c, f-ct5d, and f-ct11, bearing imidazo[4,5-b]pyrazin-2-ylidene cyclometalates are prepared and characterized in detail. Both f-ct5c and f-ct5d (also their mixture f-ct5mix) gave intensive blue emissions peaking at ≈465 nm with short radiative lifetimes of 1.

Recent Advances in Pristine Iron Triad Metal-Organic Framework Cathodes for Alkali Metal-Ion Batteries.

Pristine iron triad metal-organic frameworks (MOFs), i.e., Fe-MOFs, Co-MOFs, Ni-MOFs, and heterometallic iron triad MOFs, are utilized as versatile and promising cathodes for alkali metal-ion batteries, owing to their distinctive structure characteristics, including modifiable and designable composition, multi-electron redox-active sites, exceptional porosity, and stable construction facilitating rapid ion diffusion.

Wearable and Wavelength-Tunable Near-Infrared Organic Light-Emitting Diodes for Biomedical Applications.

Near-infrared organic light-emitting diodes (NIR OLEDs) have significant potential for wearable phototherapeutic applications because of the unique properties of the OLEDs, including their free-form electronics and the excellent biomedical effects of NIR emission. In spite of their tremendous promise, given that the majority of NIR OLEDs in previous research have relied on the utilization of an intrinsically brittle indium tin oxide (ITO) electrode, their practicality in the field of wearable electronics is inherently constrained. Here, we report wearable and wavelength-tunable NIR OLEDs that employ a high-performance NIR emitter and an innovative architecture by replacing the ITO with a silver (Ag) electrode.

Construction of Low-Cost Z-Scheme Heterojunction CuO/PCN-250 Photocatalysts Simultaneously for the Enhanced Photoreduction of CO to Alcohols and Photooxidation of Water.

Solar-driven high-efficiency conversion of CO with water vapor into high-value-added alcohols is a promising approach for reducing CO emissions and achieving carbon neutrality. However, the rapid recombination of photogenerated carriers and low CO adsorption capacity of photocatalysts are usually the factors that limit their applicability. Herein, a series of low-cost Z-scheme heterostructures CuO/PCN-250- are constructed by growth of ultrasmall CuO nanoparticles on PCN-250.

D-A-Type Molecules with Free Rotors for Highly Efficient Interfacial Solar-Driven Steam Generation and Thermoelectric Performance.

Three "π"-shaped D-A-type thiodiazoloquinoxaline derivatives with different electronic structures and rotations have been prepared. Their particular structures allow these molecules to possess a broad absorption range and sufficient intramolecular motions, dissipating energy through a thermal deactivation pathway. Among the three materials, showed the best steam generation efficiency (84.

Blue Electrophosphorescence from Iridium(III) Phosphors Bearing Asymmetric Di-N-aryl 6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridin-2-ylidene Chelates.

Efficient blue phosphors remain a formidable challenge for organic light-emitting diodes (OLEDs). To circumvent this obstacle, a series of Ir(III)-based carbene complexes bearing asymmetric di-N-aryl 6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridin-2-ylidene chelates, namely, f-ct6a‒c, are synthesized, and their structures and photophysical properties are comprehensively investigated. Moreover, these emitters can undergo interconversion in refluxing 1,2,4-trichlorobenzene, catalyzed by a mixture of sodium acetate (NaOAc) and p-toluenesulfonic acid monohydrate (TsOH·HO) without decomposition.

Uncovering the Role of Crystal Phase in Determining Nonvolatile Flash Memory Device Performance Fabricated from MoTe-Based 2D van der Waals Heterostructures.

Although the crystal phase of two-dimensional (2D) transition metal dichalcogenides (TMDs) has been proven to play an essential role in fabricating high-performance electronic devices in the past decade, its effect on the performance of 2D material-based flash memory devices still remains unclear. Here, we report the exploration of the effect of MoTe in different phases as the charge-trapping layer on the performance of 2D van der Waals (vdW) heterostructure-based flash memory devices, where a metallic 1T'-MoTe or semiconducting 2H-MoTe nanoflake is used as the floating gate. By conducting comprehensive measurements on the two kinds of vdW heterostructure-based devices, the memory device based on MoS/h-BN/1T'-MoTe presents much better performance, including a larger memory window, faster switching speed (100 ns), and higher extinction ratio (10), than that of the device based on the MoS/h-BN/2H-MoTe heterostructure.

Layered Double Hydroxides: A Novel Promising 2D Nanomaterial for Bone Diseases Treatment.

Bone diseases including bone defects, bone infections, osteoarthritis, and bone tumors seriously affect life quality of the patient and bring serious economic burdens to social health management, for which the current clinical treatments bear dissatisfactory therapeutic effects. Biomaterial-based strategies have been widely applied in the treatment of orthopedic diseases but are still plagued by deficient bioreactivity. With the development of nanotechnology, layered double hydroxides (LDHs) with adjustable metal ion composition and alterable interlayer structure possessing charming physicochemical characteristics, versatile bioactive properties, and excellent drug loading and delivery capabilities arise widespread attention and have achieved considerable achievements for bone disease treatment in the last decade.

Carbon Nanodots Memristor: An Emerging Candidate toward Artificial Biosynapse and Human Sensory Perception System.

In the era of big data and artificial intelligence (AI), advanced data storage and processing technologies are in urgent demand. The innovative neuromorphic algorithm and hardware based on memristor devices hold a promise to break the von Neumann bottleneck. In recent years, carbon nanodots (CDs) have emerged as a new class of nano-carbon materials, which have attracted widespread attention in the applications of chemical sensors, bioimaging, and memristors.

Insights into self-degradation of cysteine esters and amides under physiological conditions yield new cleavable chemistry.

An unprecedented HS release from cysteine esters and amides (CysO/NHR) under physiological conditions was discovered and the plausible mechanism was proposed. Alkylation of the amino moiety of cysteine esters enables the HS release to be tuned and further provides support to the mechanistic insights. This discovery not only provides new insights into several fundamental science issues including non-enzymatic HS-produced pathways, but also inspires new tunable cleavable motifs for sustained release of arylthiols and even for prodrug design.

Coupling Probiotics with 2D CoCuMo-LDH Nanosheets as a Tumor-Microenvironment-Responsive Platform for Precise NIR-II Photodynamic Therapy.

Photodynamic therapy (PDT) has become a promising cancer treatment approach with superior advantages. However, it remains a grand challenge to develop tumor microenvironment (TME)-responsive photosensitizers (PSs) for tumor-targeting precise PDT. Herein, the coupling Lactobacillus acidophilus (LA) probiotics with 2D CoCuMo layered-double-hydroxide (LDH) nanosheets (LA&LDH) is reported as a TME-responsive platform for precise NIR-II PDT.

Excited-State THz Vibrations in Aggregates of Pt Complexes Contribute to the Enhancement of Near-Infrared Emission Efficiencies.

The exploration of deactivation mechanisms for near-infrared(NIR)-emissive organic molecules has been a key issue in chemistry, materials science and molecular biology. In this study, based on transient absorption spectroscopy and transient grating photoluminescence spectroscopy, we demonstrate that the aggregated Pt complex 4H (efficient NIR emitter) exhibits collective out-of-plane motions with a frequency of 32 cm (0.96 THz) in the excited states.

Boosting the Sonodynamic Cancer Therapy Performance of 2D Layered Double Hydroxide Nanosheet-Based Sonosensitizers Via Crystalline-to-Amorphous Phase Transformation.

Sonodynamic therapy (SDT) has been a promising therapeutic modality for cancer because of its superior advantages compared with other therapeutic strategies. However, the current sonosensitizers used for SDT normally exhibit low activity for ultrasound (US)-induced reactive oxygen species (ROS) generation. Herein, the crystalline-to-amorphous phase transformation is reported as a simple but powerful strategy to engineer ultrathin 2D CoW-LDH and NiW-LDH nanosheets as highly efficient sonosensitizers for SDT.

3D printing flexible zinc-ion microbatteries with ultrahigh areal capacity and energy density for wearable electronics.

A flexible zinc ion micro-battery with ultra-high surface capacity (10.1 mA h cm) and energy density (8.1 mW h cm), as well as good flexibility, is fabricated based on the co-doping effect of VO through an improved 3D printing technology, and is further integrated with flexible solar cells for self-powered wearable electronics.

Encapsulating Organic Dyes in Metal-Organic Frameworks for Color-Tunable and High-Efficiency White-Light-Emitting Properties.

The design of white-light phosphor is highly desirable for practical applications in SSL (solid-state lighting) and its related fields. Dye-loaded metal-organic frameworks (MOFs) have been widely demonstrated as one type of promising down conversion materials for WLEDs (white-light-emitting diodes), but two issues (dye leakage and inadequate quantum efficiency) require to be addressed before possible applications. Here, a series of single-phase dyes@In-MOF phosphors have been prepared in two different ways: the in-situ process and soaking method.

A MgFe-LDH Nanosheet-Incorporated Smart Thermo-Responsive Hydrogel with Controllable Growth Factor Releasing Capability for Bone Regeneration.

Although growth factor (GF)-loaded hydrogels have been explored as promising materials in repairing bone defects, it still remains challenging to construct smart hydrogels with excellent gelation/mechanical properties as well as controllable GF releasing capability. Herein, the incorporation of bone morphogenetic protein 2 (BMP-2)-functionalized MgFe-layered double hydroxide (LDH) nanosheets into chitosan/silk fibroin (CS) hydrogels loaded with platelet-derived growth factor-BB (PDGF-BB) to construct a smart injectable thermo-responsive hydrogel (denoted as CSP-LB), which can achieve a burst release of PDGF-BB and a sustained release of BMP-2, for highly efficient bone regeneration is reported. The incorporation of MgFe-LDH in CS hydrogel not only shortens the gelation time and decreases sol-gel transition temperature, but also enhances the mechanical property of the hydrogel.