The rise of two-dimensional tellurium for next-generation electronics and optoelectronics

Single-element two-dimensional(2D)tellurium(Te)which possesses an unusual quasi-one-dimensional atomic chain structure is a new member in 2D materials family.2D Te possesses high carrier mobility,wide tunable bandgap,strong light-matter interaction,better environmental stability,and strong anisotropy,making Te exhibit tremendous application potential in next-generation electronic and optoelectronic devices.However,as an emerging 2D material,the research on fundamental property and device application of Te is still in its infancy.Hence,this review summarizes the most recent research progresses about the new star 2D Te and discusses its future development direction.Firstly,the structural features,basic physical properties,and various preparation methods of 2D Te are systemically introduced.Then,we emphatically summarize the booming development of 2D Te-based electronic and optoelectronic devices including field effect transistors,photodetectors and van der Waals heterostructure photodiodes.Finally,the future challenges,opportunities,and development directions of 2D Te-based electronic and optoelectronic devices are prospected.

A new spirofluorene-based nonplanar PBI-dyad and its utilization in the film-based photo-production of singlet oxygen

Traditional photosensitizers are predominantly based on various types of polypyrrole macrocycles, which are generally used in homogeneous and/or suspension states. In the present study, a new non-polypyrrole-based photosensitizer(LW-PBI) was developed via the introduction of a nonplanar spirofluorene into a derivative of perylene bisimides(PBI) containing two longalkyl chains. Photophysical studies demonstrated that the compound shows good solubility in common organic solvents, great photochemical stability, and high absorption efficiency in the visible light region. Due to containing of two energetically matchable, independent fluorescent units, the compound as prepared displays strong tendency to form non-fluorescent chargeseparated states under light irradiation in polar solvents. Based on the merits, LW-PBI was examined for its catalytic property in the photo-production of singlet oxygen in film state. Luckily, the compound is an effective photosensitizer in the generation of the active oxygen species as verified by its unique reaction with uric acid(UA). Further studies revealed that the effective photoproduction of singlet oxygen can be also realized via the utilization of a tiny and low-price LED lamp as a light source and as a film support. Detailed studies on the application of the conceptual device as a medical instrument for photodynamic therapy(PDT) are in progress.

Application of red mud as a basic catalyst for biodiesel production

Red mud was investigated in triglyceride transesterification with a view to determine its viability as a basic catalyst for use in biodiesel synthesis.The effect of calcination temperature on the structure and activity of red mud catalysts was investigated.It was found that highly active catalyst was obtained by simply drying red mud at 200°C.Utilization of red mud as a catalyst for biodiesel production not only provides a cost-effective and environmentally friendly way of recycling this solid red mud waste,significantly reducing its environmental effects,but also reduces the price of biodiesel to make biodiesel competitive with petroleum diesel.

Cobalt-catalyzed asymmetric hydrogenation of ketones:A remarkable additive effect on enantioselectivity

A chiral cobalt pincer complex,when combined with an achiral electron-rich mono-phosphine ligand,catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones,affording chiral alcohols with high yields and moderate to excellent enantioselectivities(29 examples,up to 93%ee).Notably,the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.

A Configurationally Tunable Perylene Bisimide Derivative-based Fluorescent Film Sensor for the Reliable Detection of Volatile Basic Nitrogen towards Fish Freshness Evaluation

Rapid and real-time mon itoring of food quality plays critical roles in the food industry and for the gen era I public health.Herei n,we specially synthesized a new perylene bisimide(PBI)derivative(PCB-EpE)composed of two PBI units and a rigid o-carborane linker,which was further employed in constructi ng a con ceptual fluoresce nt film sen sor for evaluati ng fish fresh ness.Photophysical studies indicate that PCB-EpE displays an open"Z-type"molecular configuration in chloroform and a closed"△-type"configuration in methyl cyclohexa ne.Comparatively,"Z-type"molecular configurati on possesses higher fluoresce nee qua ntum yield and is more sen sitive toward volatile basic nitrogen(VBN).

Instantaneous visual imaging of latent fingerprints in water

Fingerprints are widely acknowledged as crucial evidence for personal identification and security,among which the invisible latent fingerprints(LFPs)is one of the most common and arduous proofs in investigations of crime scenes[1].Conventional imaging techniques suffer from various limitations like low contrast and sensitivity[2],which can only recognize macroscopic features of LFPs,including shape,core,ending,bifurcation,and island(Levels 1 and 2).Alternatively,aggregation-induced emission(AIE)materials[3]have shown great potential in visualizing LFPs with microscopic details,like pores,ridges and their edges(Level 3),due to their strong fluorescence,easy functionalization,and intrinsic AIE characteristics[4].Despite these advances,several issues still hamper the practical application of AIE probes in this field:(1)organic solvents rather than environmentally more benign water are used in most cases with extended incubation time;(2)cheap,general,and colortunable probes for LFPs are still missing[5],which hampered their practical application for different scenarios;(3)in-depth understanding of the plausible mechanism for the visual imaging of LFPs at molecular level is still underdeveloped in most cases.

Excimer Formation of Perylene Bisimide Dyes within Stacking-Restrained Folda-Dimers:Insight into Anomalous Temperature Responsive Dual Fluorescence

We have fabricated a new perylene bisimide(PBI)folda-dimer(BPBI-CB-1)by tethering two PBI moieties to the ortho-carbon positions of a carborane unit.The synthesized compound adopted distinct configurations in different solvents with dual emissions as its characteristic.The two PBI moieties in the molecule appeared either in a weakly interacted,monomer-like state or brought into close π-π contact with each other,forming an interacted stacking state.The equilibrium between these two states was governed by the nature of solvents and testing temperature.Spectroscopic and theoretical studies concluded that dual emission bands originated from intramolecular monomer-like and stacking states,respectively.Remarkably,in a solvent like 1,2-dichloroethane(DCE),both emission intensities increased with rising temperatures.The positive temperature response of the monomer emission was ascribed to an increased amount of monomer-like population,owing to its endothermic energy state,while the excimer emission was rationalized by increased population of the bright exciton state,resulting in an increased emission yield that compensated the diminished population of the stacking state.To our knowledge,this is the first report on positive temperature-responsive dual emissions associated with the synergism of intramolecular intersubunit aggregation/dissociation and excimer transformation.

An AIE probe for long-term plasma membrane imaging and membrane-targeted photodynamic therapy

Two red-emissive luminogens(TPTH and TPTB) with typical aggregation-induced emission characteristics were developed. By introducing the heavy atom of Br at the end of alkyl chain, TPTB exhibited higher reactive oxygen species generation efficiency through both types I and II pathways. Due to its excellent biocompatibility and proper lipophilicity, TPTB could be used for long-term cell membrane staining and this staining ability was independent of the change of plasma membrane potential. Furthermore, TPTB could ablate the cancer cells through cell membrane-targeted photodynamic therapy.

Anthrazoline Photocatalyst for Promoting Esterification and Etherification Reactions via Photoredox/Nickel Dual Catalysis

Here,we demonstrate a readily prepared anthrazoline photocatalyst,which can effectively promote C—O bond formation reactions with the aid of Ni(II)complex.This methodology enables the esterification(36 examples)and etherification(8 examples)with a broad range of scope,allowing aryl and alkyl halides coupled with diverse carboxylic acids/alcohols.Our metal-free photocatalysts have a potential broad application,may serve as an alternative to some iridium and ruthenium based photocatalysts,and are of potential importance to the pharmaceutical industry.

Bi-ortho-Carborane Unit-Riveted Perylene Monoimides:Structure-Tuned Optical Switches for Electron Transfer and Robust Thin Film-Based Fluorescence Sensors

Innovative design of sensing fluorophores possessing superior photophysical properties,porosity,and packing-resistance structures is pivotal for high performance film-based fluorescent sensors.Herein,PDCB,a perylene monoimide(PMI)derivative incorporating large spatial phenyl-carborane was synthesized and found to exhibit unexpected photophysical properties.The structurally bent PDCB exhibits not only PMI-like emission but also a red-shifted emission.In sharp contrast,PMI-CBH,a linear PMI derivative,exhibits only PMI-like emission.Furthermore,upon local excitation,PDCB undergoes a photoinduced electron transfer(PET)between PMI and phenylcarborane,resulting in a charge-transfer state.Two other PMI derivatives,PCB and PDCBP,showed a similar phenomenon.The PET rate is in the order of PCB(48 ps^(-1))>PDCB(163 ps^(-1))>PDCBP(815 ps^(-1))in toluene,which decreases with increasing steric hindrance,inferring structure reorganization prior to the PET process.As expected,a fabricated PDCB-based sensor showed excellent performance in acetone sensing.

Orthogonal carbazole-perylene bisimide pentad:a photoconversion-tunable photosensitizer with diversified excitation and excited-state relaxation pathways

Integrating multiple photosensitive properties into an“all-in-one”photosensitizer(PS)shows great promise for the treatment of cancers owing to synergistic effect among them.However,the development of such PSs,especially those that need a single laser source,remains a challenge.Herein,we report an orchestration of electron donors and acceptors in a propeller-like pentad,PBI-4Cz,where four carbazole(Cz)units are covalently linked to the ortho-positions of the perylene bisimide(PBI)core.Strong intramolecular donor-acceptor interaction significantly quenches the luminescence and largely extends the absorption spectra to near-infrared region.Excited-state dynamics investigated via femto-and nano-second transient absorption spectroscopy revealed exclusive charge separation of the PBI-4Cz within initial 0.5 ps when photoexcited regardless of which intermediate is involved.Energy dissipation of the resulting charge-separated state(PBI^(•−)-4Cz^(•−))is subjected to the toggle between intersystem-crossing toward excited triplet states and charge recombination toward ground states.Relative importance of the two pathways can be tuned by micro-environmental polarity,which endows PBI-4Cz remarkable performances of singlet-oxygen generation(>90.0%)in toluene and photothermal conversion(∼28.6%)in DMSO.Harnessing intrinsic photostability and excited-state processes of heavy-atom-free PBI derivatives not only holds a promise for multifunctional phototheranostics,but also provides a prototype for designing high-performance PSs with tunable photoconversion pathways.

Esterase-Activated Theranostic Prodrug for Dual Organelles-Targeted Imaging and Synergetic Chemo-Photodynamic Cancer Therapy

Activatable prodrugs have received considerable attention in cancer therapy due to their high specificity and reduced side effects.However,the theranostic prodrug with multiple cancerous organelles targeting and combinational therapy is still rare.In this report,an esterase-responsive prodrug tetraphenylethylene functionalized quinolinium-ester-chlorambucil(TPEQC)was developed for dual organelles-targeted and image-guided cancer therapy through synergetic chemotherapy(CT)and photodynamic therapy(PDT).TPE-QC was constructed by conjugating an anticancer drug of chlorambucil with an aggregation-induced emission active photosensitizer of tetraphenylethylene functionalized hydroxyethyl quinolinium(TPE-QO)via the hydrolyzable ester linkage.The fluorescence and photosensitization of TPE-QC were initially quenched because of the photoinduced electron transfer(PET)effect.After reacting with esterase,the ester group of TPE-QC could be selectively hydrolyzed to release chlorambucil and TPE-QO,which terminated the PET process and switched on the fluorescence and photosensitization.Benefitting from the overexpressed esterase in cancer cells,TPE-QC could be efficiently activated in cancer cells rather than in normal cells,while the restoredfluorescence could preciselymonitor the release of TPE-QC.Importantly,activated TPE-QC accumulated in both organelles of lysosome and mitochondria,resulting in enhanced anticancer potency.In vivo experiments demonstrated that TPE-QC displayed efficient tumor microenvironment-activatable features and excellent tumor therapeutic effects through combinational CT and PDT.

薄膜荧光传感器:从敏感材料到硬件结构

Film-based fluorescent sensors (FFSs) differentiate themselves from conventional sensors and disposable probes owing to their fascinating merits of small size, power saving, easy operation, as well as high sensitivity and designability. Therefore, they were recently selected by the International Union of Pure and Applied Chemistry as one of the Top Ten Emerging Technologies in Chemistry 2022 [1].

Nonplanar Perylene Monoimide-Based Fluorescent Film for Enhanced BTX Sensing

Film-based fluoresce nt sen sors have been adapted into portable devices for the vapor phase detecti on.The satisfactory sensing performs nee(e.g.,sen sitivity,selectivity,reusability)largely bene fits from fluorophores.