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Two 2-substituted 8-hydroxyquinoline ligands ( HL 1 and HL 2 ) containing a cyano group were synthesized and characterized by ESI-MS, NMR spectroscopy and elemental analysis (EA). Solvothermal reactions of the two ligands with ZnX 2 and CdX 2 (X − : NO 3 − and OAc − ) salts afforded three luminescent complexes, i.e., monomeric Zn(II) complex [Zn(L 1 ) 2 ] ( 1 ), trimeric Zn(II) complex [Zn 3 (L 2 ) 6 ] ( 2 ) and tetrameric Cd(II) complex [Cd 4 (L 2 ) 8 ] ( 3 ). These three complexes were characterized by single crystal X-ray diffractions, powder X-ray diffractions (PXRD), thermogravimetry analyses (TGA) and EA, illustrating a lamellar structure facilitated by noncovalent interactions such as aromatic π⋯π stacking and C–H⋯N H-bonds. Further investigations by UV–Vis, photoluminescence (PL) and fluorescence lifetime reveal tunable luminescence from yellow to red among 1 – 3 in the solid state. [ABSTRACT FROM AUTHOR]

Two novel complexes, tetramer [Co 4 L 8 ] ( 1 ) and dimer [Cu 2 L 4 ] ( 2 ) (L = ( E )-2-(2-fluoro-4-methoxystyryl)-8-hydroxyquinoline), were synthesized and characterized by single-crystal X-ray diffractions, powder X-ray diffractions (PXRD), thermal-gravimetric analyses (TGA), infrared radiation (IR) and elemental analyses (EA). In the solid state, both of their supramolecular structures were constructed by C H⋯F dispersive interactions. In addition, the differences in the structure between 1 and 2 have been discussed: supramolecular structures of complex 1 were constructed by C H⋯O and C F⋯π intermolecular interactions, however, supramolecular structures of complex 2 were mainly constructed by C F⋯F C intermolecular interactions and π⋯π stacking. Obviously, the C F group which takes part in attractive interactions with other molecules is important to construct supramolecular structures and plays different roles in the two novel complexes. Magnetic analysis of 1 indicates that the antiferromagnetic coupling dominates the magnetic properties. [ABSTRACT FROM AUTHOR]

A novel 2-substituted-8-hydroxyquinoline ligand ( E )-2-[2-(4-trifluoromethylphenyl)ethenyl]-8-hydroxyquinoline ( 3 , HL ) was synthesized and characterized by ESI-MS, NMR spectroscopy and elemental analysis. Using solvothermal method, a trimeric complex [Zn 3 L 6 ] ( 4 ) was fabricated by self-assembly of Zn(II) ions with 3 . X-ray structural analysis shows that 4 exhibits a trinuclear core, which was bridged and encapsulated by six 8-hydroxyquinolinate-based ligands. The supramolecular structure of 4 features a lamellar solid constructed by aromatic stacking interactions and nonclassical C–H···F hydrogen bonds derived from 4-trifluoromethylphenyl group of the 3 . The coordination behavior of zinc salt and 3 in solution was performed by 1 H NMR, UV–vis and Photoluminescence (PL). The experimental results show that the complex 4 emits yellow luminescence in the solid state. To investigate its properties further, we also studied the thermal stability, photophysical properties (fluorescent emission, lifetime) of complex 4 , and the interactions between 4 and C 60 or EtBr–DNA system. [ABSTRACT FROM AUTHOR]

One novel tetranuclear Cd(II) complex with formula [Cd 4 L 6 (NO 3 ) 2 ] ( 1 ) is accessible by solvothermal reaction of Cd(NO 3 ) 2 with a ( E )-2-[2-(3-thienyl)ethenyl]-8-quinolinol ligand ( HL ), which was characterized by means of 1 H NMR, ESI-MS, elemental analysis, IR and TGA. X-ray structural analysis indicated that 1 exhibited a double open cubane-like core structure, which was bridged by six 8-hydroxyquinolinate-based ligand. Rich aromatic stacking interactions and non-classical C–H···O weak interactions sustain the packing structure. The coordination behavior of cadmium salt and HL in solutions was performed by UV–vis and photoluminescence (PL). The experimental results corroborate that emission spectrum of the title complex in the solid state at room temperature gives strong yellow-green luminescence. In addition, the thermal stability, fluorescent lifetime, electronic calculation and quenching behaviors of C 60 and EtBr-DNA interacted with the compound were also investigated. [ABSTRACT FROM AUTHOR]

A series of 2-arylethenyl-8-hydroxyquinoline ligands ( A1 – A4 ) with a trimethoxyphenyl, naphthyl, 2-fluoro-4-bromophenyl and anthracenyl group and their corresponding Zn(II) complexes ( B1 – B4 ) were synthesized and characterized by means of 1 H NMR, ESI-MS, FT-IR and elemental analysis. A1 and A4 were characterized by single-crystal X-ray crystallography. The aggregation behavior of zinc salt and ligands in solution was investigated by several techniques, containing 1 H NMR, UV–vis and photoluminescence (PL). The electronic nature and volume of arylethenyl substituents affect the absorption wavelength, the emission color, fluorescence lifetime, fluorescence quantum yield and thermostability of Zn(II) complexes. The experiments corroborated that the properties of Zinc(II) complexes can be tuned by introducing different functional substituents. [ABSTRACT FROM AUTHOR]

Thedifferentiation of two nucleophilic amide groups in malonamidesthrough a copper-catalyzed enantioselective intramolecular aryl C–Ncoupling reaction is demonstrated based on an asymmetric desymmetrizationstrategy. Such a method afforded enantioenriched 2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxamidesin high yields and moderate to good enantioselectivity. [ABSTRACT FROM AUTHOR]

The nonlinear optical properties, including two-, three-photon and excited-state absorption phenomena, were observed in three oligomerfluorene derivatives (abbreviated as OF3, OF5 and OF7) by femtosecond (450 fs) laser pulses. Their two-, three-photon and, excited-state absorption properties were studied by open Z-scan and pump-probe measurements. Interestingly, when the numbers of fluorene units increased from 3 to 5, and to 7, the corresponding absorption phenomena changed from three-photon to two-photon induced excited-state phenomena, showed strong structure dependence in these derivatives. The results offer a method to design and synthesize organic molecules for multiphoton materials. It was noted that the three-photon cross-section value ( δ) of OF3 was up to 1.36×10 cm s. Correspondingly, the two-photon ( δ) and excited-state cross-section ( δ) values of OF5 and OF7 also were obtained, and they were 1230 GM and 0.91×10 cm for OF5, and 1780 GM and 1.18×10 cm for OF7, respectively. [ABSTRACT FROM AUTHOR]

Currently, most photoredox catalysis polymerization systems are limited by high excitation power, long polymerization time, or the requirement of electron donors due to the precise design of efficient photocatalysts still poses a great challenge. Herein, we propose a new approach: the creation of efficient photocatalysts having low ground state oxidation potentials and high excited state energy levels, along with through‐space charge transfer (TSCT) induced intersystem crossing (ISC) properties. A cabazole‐naphthalimide (NI) dyad (NI‐1) characterized by long triplet excited state lifetime (τT=62 μs), satisfactory ISC efficiency (ΦΔ=54.3 %) and powerful reduction capacity [Singlet: E1/2 (PC+1/*PC)=−1.93 eV, Triplet: E1/2 (PC+1/*PC)=−0.84 eV] was obtained. An efficient and rapid polymerization (83 % conversion of 1 mM monomer in 30 s) was observed under the conditions of without electron donor, low excitation power (10 mW cm−2) and low catalyst (NI‐1) loading (<50 μM). In contrast, the conversion rate was lower at 29 % when the reference catalyst (NI‐4) was used for photopolymerization under the same conditions, demonstrating the advantage of the TSCT photocatalyst. Finally, the TSCT material was used as a photocatalyst in practical lithography for the first time, achieving pattern resolutions of up to 10 μm. [ABSTRACT FROM AUTHOR]

Currently, most photoredox catalysis polymerization systems are limited by high excitation power, long polymerization time, or the requirement of electron donors due to the precise design of efficient photocatalysts still poses a great challenge. Herein, we propose a new approach: the creation of efficient photocatalysts having low ground state oxidation potentials and high excited state energy levels, along with through‐space charge transfer (TSCT) induced intersystem crossing (ISC) properties. A cabazole‐naphthalimide (NI) dyad (NI‐1) characterized by long triplet excited state lifetime (τT=62 μs), satisfactory ISC efficiency (ΦΔ=54.3 %) and powerful reduction capacity [Singlet: E1/2 (PC+1/*PC)=−1.93 eV, Triplet: E1/2 (PC+1/*PC)=−0.84 eV] was obtained. An efficient and rapid polymerization (83 % conversion of 1 mM monomer in 30 s) was observed under the conditions of without electron donor, low excitation power (10 mW cm−2) and low catalyst (NI‐1) loading (<50 μM). In contrast, the conversion rate was lower at 29 % when the reference catalyst (NI‐4) was used for photopolymerization under the same conditions, demonstrating the advantage of the TSCT photocatalyst. Finally, the TSCT material was used as a photocatalyst in practical lithography for the first time, achieving pattern resolutions of up to 10 μm. [ABSTRACT FROM AUTHOR]

Current research of triplet–triplet annihilation upconversion (TTA-UC) faces difficulty such as overuse of organic solvents and quenching of excited triplet sensitizers by molecular oxygen. Herein, we propose an efficient and facile preparation strategy of TTA-UC microemulsion to overcome these issues. With simple device and short preparation process, air-stable TTA-UC with a high upconversion efficiency of 16.52% was achieved in microemulsion coassembled from TritonX114, tetrahydrofuran and upconverting chromophores (platinum octaethyl-porphyrin and 9,10-diphenylanthracene). This is comparable to the highest UC efficiency ever reported for TTA-UC microemulsion systems. The excellent UC performance of TX114–THF could be attributed to two perspectives. Firstly, small-size micelle accommodated chromophores up to high concentrations in organic phase, which promoted efficient molecular collision. Additionally, high absorbance at 532 nm ensured full use of excitation light, getting more long wavelength photons involved in the TTA-UC process. Moreover, air-stable TTA-UC also performed well in microemulsion with various surfactants, including nonionic surfactants (Tween 20, Tween 80, Triton X-110, Triton X-114), ionic surfactants (sodium dodecyl sulfate, cetyltrimethyl ammonium bromide) and block copolymers (pluronic F127, pluronic P123), through three conjectural assembly models according to the structural characteristics of surfactant molecules (concentrated, uncompacted and scattered). These discoveries could provide estimable reference for selection of surfactants in relevant fields of TTA-UC. [ABSTRACT FROM AUTHOR]

Bismuth (Bi) possesses an ultrahigh theoretical volume capacity (3800 mAh cm−3) and low embedding potential stimulated considerable attention as anodes for sodium‐ion batteries (SIBs). However, its practical application is still hampered by the huge volume variation during the charge/discharge process. To settle this issue, Bi@C nanosheet arrays (Bi@C‐NSA) are fabricated on copper foam via a facile galvanic replacement followed by in situ polymerization of dopamine and an annealing procedure. The carbon‐coated nanosheet array structure not only accommodates the volume expansion during cycling and maintains electrode stability, but also facilitates rapid electron/ion transport. Due to the unique structural design, this Bi@C‐NSA exhibits an impressive capacity of 315.72 mAh g−1 after 1500 cycles under 1 A g−1. Furthermore, a series of in situ/ex situ techniques reveal that this Bi@C‐NSA possesses superior reaction kinetics and undergoes a typical alloying/dealloying storage mechanism. Furthermore, Bi@C‐NSA also achieves commendable reversible capacity and cycling stability in a wide temperature range (0 °C–60 °C). Notably, the assembled Na3V2(PO4)3//Bi@C‐NSA full cell demonstrates a capacity of 325 mAh g−1 after 50 cycles at 0.05 A g−1, which promises for practical applications. This galvanic replacement strategy spearheads a way to prepare nanoarray electrodes and will accelerate the development of sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials hold great promise for advanced high‐resolution organic light‐emitting diode (OLED) displays. However, persistent challenges, such as severe aggregation‐caused quenching (ACQ) and slow spin‐flip, hinder their optimal performance. We propose a synergetic steric‐hindrance and excited‐state modulation strategy for MR‐TADF emitters, which is demonstrated by two blue MR‐TADF emitters, IDAD‐BNCz and TIDAD‐BNCz, bearing sterically demanding 8,8‐diphenyl‐8H‐indolo[3,2,1‐de]acridine (IDAD) and 3,6‐di‐tert‐butyl‐8,8‐diphenyl‐8H‐indolo[3,2,1‐de]acridine (TIDAD), respectively. These rigid and bulky IDAD/TIDAD moieties, with appropriate electron‐donating capabilities, not only effectively mitigate ACQ, ensuring efficient luminescence across a broad range of dopant concentrations, but also induce high‐lying charge‐transfer excited states that facilitate triplet‐to‐singlet spin‐flip without causing undesired emission redshift or spectral broadening. Consequently, implementation of a high doping level of IDAD‐BNCz resulted in highly efficient narrowband electroluminescence, featuring a remarkable full‐width at half‐maximum of 34 nm and record‐setting external quantum efficiencies of 34.3 % and 31.8 % at maximum and 100 cd m−2, respectively. The combined steric and electronic effects arising from the steric‐hindered donor introduction offer a compelling molecular design strategy to overcome critical challenges in MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials hold great promise for advanced high‐resolution organic light‐emitting diode (OLED) displays. However, persistent challenges, such as severe aggregation‐caused quenching (ACQ) and slow spin‐flip, hinder their optimal performance. We propose a synergetic steric‐hindrance and excited‐state modulation strategy for MR‐TADF emitters, which is demonstrated by two blue MR‐TADF emitters, IDAD‐BNCz and TIDAD‐BNCz, bearing sterically demanding 8,8‐diphenyl‐8H‐indolo[3,2,1‐de]acridine (IDAD) and 3,6‐di‐tert‐butyl‐8,8‐diphenyl‐8H‐indolo[3,2,1‐de]acridine (TIDAD), respectively. These rigid and bulky IDAD/TIDAD moieties, with appropriate electron‐donating capabilities, not only effectively mitigate ACQ, ensuring efficient luminescence across a broad range of dopant concentrations, but also induce high‐lying charge‐transfer excited states that facilitate triplet‐to‐singlet spin‐flip without causing undesired emission redshift or spectral broadening. Consequently, implementation of a high doping level of IDAD‐BNCz resulted in highly efficient narrowband electroluminescence, featuring a remarkable full‐width at half‐maximum of 34 nm and record‐setting external quantum efficiencies of 34.3 % and 31.8 % at maximum and 100 cd m−2, respectively. The combined steric and electronic effects arising from the steric‐hindered donor introduction offer a compelling molecular design strategy to overcome critical challenges in MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

Organic photosensitizers (PSs) with aggregation‐induced emission (AIE) characteristics have shown several advantages in photodynamic therapy (PDT). However, how to design PSs with the required optical and biological properties is a formidable challenge. In this work, a series of AIE active pyridine‐ and pyridinium‐functionalized carbazole with different substituents are designed and synthesized. Compared to other analogs, BK‐Pys‐BP containing benzophenone moiety on the pyridinium unit produces reactive oxygen species (ROS) efficiently in the presence of light due to its large spin‐orbit coupling constant to promote efficient intersystem crossing. Based on its structure, three molecules with enhanced donor–acceptor strength and conjugation are further investigated to realize emission covering the whole visible region. The cationic nature and excellent ROS generation ability of benzophenone‐containing AIE photosensitizers allows for specific imaging of mitochondria, killing cancer cells, and as a singlet oxygen donor to catalyze the formation of endoperoxides. Thus, the present work presents an effective strategy for creating AIE photosensitizers with efficient ROS generation for wide biological applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: By employing the asymmetric end‐group engineering, an asymmetric nonfused‐ring electron acceptor (NFREA) was designed and synthesized. Compared with the symmetric analogs (NoCA‐17 and NoCA‐18), NoCA‐19 possesses broader light absorption range, more coplanar π‐conjugated backbone, and appropriate crystallinity according to the experimental and theoretical results. The organic solar cells based on J52:NoCA‐19 exhibited a power conversion efficiency as high as 12.26%, which is much higher than those of J52:NoCA‐17 (9.50%) and J52:NoCA‐18 (11.77%), mainly due to more efficient exciton dissociation, better and balanced charge mobility, suppressed recombination loss, shorter charge extraction time, longer charge carrier lifetimes, and more favorable blend film morphology. These findings demonstrate the great potential of asymmetric end‐group engineering in exploring low‐cost and high‐performance NFREAs. [ABSTRACT FROM AUTHOR]

We present a red light-activated zincII bis(dipyrrin) symmetry breaking charge transfer (SBCT) architecture, showing a large molar absorption coefficient (ε = 15.4 × 104 M−1 cm−1), high reactive singlet oxygen generation efficiency (ΦΔ ≈ 0.8) and long-lived triplet state (τT = 150 μs) compared to the donor–acceptor analogue dipyrrin-BF2 complex, highlighting the superiority of the SBCT approach. For the first time, we demonstrated the potential of a SBCT scaffold in red-light-induced methyl methacrylate (MMA) polymerization, using a dual photocatalyst excitation approach. [ABSTRACT FROM AUTHOR]

Selective and concise construction of ring systems that are ubiquitous skeletons across chemistry, drugs and materials, is indispensable for human life. Of note, directed C−H annulation with alkynes for the expedient delivery of ring systems holds great importance, featuring step‐ and atom‐economy, mild conditions, and broad substrate scope. However, regioselectivity issues remained when using unsymmetrical alkynes for the directed C−H annulation. Herein, we summarized recent achievements towards solving this problem by developing directing groups, metal catalysts, and alkynes with versatile and traceless functionality that ensure the overall regioselectivity, enantioselectivity, efficiency, and synthetic application. We hope this concept will promote the further development of the precise construction of functional molecules using C−H annulation with unsymmetrical alkynes. [ABSTRACT FROM AUTHOR]

Nitroarenes are stable, low‐cost, and readily available starting materials. The directly utilize nitroarenes in synthetically valuable C−N bond formation is of great significance, because the pre‐reduction step to corresponding amines can be avoided. Previously, phosphines and carbon monoxide (CO) are the most widely used reductants in the reductive cyclization or/and carbonylation of nitroarenes. Currently, much attention has been attracted to organosilanes as new potential reducing agents, not only because they are inexpensive, easy‐to‐handle, and mild reagents, but also various novel reaction models of nitroarenes have been explored. In this review, we mainly summarize the recent progress on the reductive coupling of nitroarenes by using organosilanes as the end reductants. We hope that a deep understanding of the reaction model and underlying working mechanism can provide a timely guideline for researchers who are interested in this fantastic area, leading to further exploration of practical and efficient reductive coupling of nitroarenes for C−N bond formation and N‐heterocycle synthesis. [ABSTRACT FROM AUTHOR]

The design of efficient heavy atom‐free triplet photosensitizers (PSs) based on through bond charge transfer (TBCT) features is a formidable challenge due to the criteria of orthogonal donor‐acceptor geometry. Herein, we propose using parallel (face‐to‐face) conformation carbazole‐bodipy donor‐acceptor dyads (BCZ‐1 and BCZ‐2) featuring through space intramolecular charge transfer (TSCT) process as efficient triplet PS. Efficient intersystem crossing (ΦΔ=61 %) and long‐lived triplet excited state (τT=186 μs) were observed in the TSCT dyad BCZ‐1 compared to BCZ‐3 (ΦΔ=0.4 %), the dyad involving TBCT, demonstrating the superiority of the TSCT approach over conventional donor‐acceptor system. Moreover, the transient absorption study revealed that TSCT dyads have a faster charge separation and slower intersystem crossing process induced by charge recombination compared to TBCT dyad. A long‐lived charge‐separated state (CSS) was observed in the BCZ‐1 (τCSS=24 ns). For the first time, the TSCT dyad was explored for the triplet‐triplet annihilation upconversion, and a high upconversion quantum yield of 11 % was observed. Our results demonstrate a new avenue for designing efficient PSs and open up exciting opportunities for future research in this field. [ABSTRACT FROM AUTHOR]

The design of efficient heavy atom‐free triplet photosensitizers (PSs) based on through bond charge transfer (TBCT) features is a formidable challenge due to the criteria of orthogonal donor‐acceptor geometry. Herein, we propose using parallel (face‐to‐face) conformation carbazole‐bodipy donor‐acceptor dyads (BCZ‐1 and BCZ‐2) featuring through space intramolecular charge transfer (TSCT) process as efficient triplet PS. Efficient intersystem crossing (ΦΔ=61 %) and long‐lived triplet excited state (τT=186 μs) were observed in the TSCT dyad BCZ‐1 compared to BCZ‐3 (ΦΔ=0.4 %), the dyad involving TBCT, demonstrating the superiority of the TSCT approach over conventional donor‐acceptor system. Moreover, the transient absorption study revealed that TSCT dyads have a faster charge separation and slower intersystem crossing process induced by charge recombination compared to TBCT dyad. A long‐lived charge‐separated state (CSS) was observed in the BCZ‐1 (τCSS=24 ns). For the first time, the TSCT dyad was explored for the triplet‐triplet annihilation upconversion, and a high upconversion quantum yield of 11 % was observed. Our results demonstrate a new avenue for designing efficient PSs and open up exciting opportunities for future research in this field. [ABSTRACT FROM AUTHOR]

The development of persistent room‐temperature phosphorescence (pRTP) materials has been rapid in recent years; however, producing pRTP materials with high luminescent characteristics, mechanical strength, and processability is a difficult issue. Herein, a new class of pRTP materials named carbonized oligomer‐like dots (CODs) is reported, which have injection molding capacity and high mechanical strength in castings. The luminescence and mechanical properties of the CODs (PN1‐PN4) may be altered by altering the quantity of phosphoric acid and diethylenetriamine using a microwave‐assisted heating technique. Among them, the longest lifetime of PN3 attains 1.21 s with an afterglow time of over 20 s, while the maximum Young's modulus of PN1 is up to 2.36 GPa. The existence of n–π* transition is beneficial to promote the intersystem crossing, and multiple hydrogen bonds in the aggregates play a crucial role in the formation of pRTP with mechanical and hot melt adhesive properties. This study may pave the way for the development of pRTP materials with superior mechanical strength in the fields of information encryption and flexible displays. [ABSTRACT FROM AUTHOR]

Dimethyl sulfoxide (DMSO), carrying a highly polarized S = O bond as the H-bond acceptor, possesses an extraordinarily high capacity to compete for H-bond formation. This strongly H-bonding character renders DMSO with a strong ability to interfere with or even disrupt self-assembled structures mediated predominantly by intermolecular H-bonds. While this might be quite disturbing in many applications, in this study, we show that oil gelation actually could benefit significantly from DMSO’s such a strong H-bond-breaking ability. More specifically, we found that use of a minute but optimized amount of DMSO, assisted further by polar acetonitrile of a suitable amount, weakens the H-bonds in the gelling network formed by organogelators to a just right extent so as to allow for a faster disassembly-reassembly of fibers in the wetted powder gelator in oil and subsequent occurrence of rapid room-temperature gelation of both light and heavy crude oils of widely ranging viscosities within 6-25 mins at gelator loadings of ≤12% w/v. [ABSTRACT FROM AUTHOR]

Review: [17 refs. [ABSTRACT FROM AUTHOR]

Organic persistent luminescence (pL) systems with photoresponsive dynamic features have valuable applications in the fields of data encryption, anticounterfeiting, and bioimaging. Photoinduced radical luminescent materials have a unique luminous mechanism with the potential to achieve dynamic pL. It is extremely challenging to obtain radical pL under ambient conditions; on account of it, it is unstable in air. Herein, a new semialiphatic polyimide‐based polymer (A0) is developed, which can achieve dynamic pL through reversible conversion of radical under photoexcitation. A "joint–donor–spacer–acceptor" molecular design strategy is applied to effectively modulate the intramolecular charge‐transfer and charge‐transfer complex interactions, resulting in effective protection of the radical generated under photoirradiation. Meanwhile, polyimide‐based polymers of A1–A4 are obtained by doping different amine‐containing fluorescent dyes to modulate the dynamic afterglow color from green to red via the triplet to singlet Förster resonance energy‐transfer pathway. Notably, benefiting from the structural characteristics of the polyimide‐based polymer, A0–A4 have excellent processability, thermal stability, and mechanical properties and can be applied directly in extreme environments such as high temperatures and humidity. [ABSTRACT FROM AUTHOR]

High‐contrast mechano‐responsive luminescence (MRL) materials with mechano‐induced emission enhancement properties are fascinating candidates but few, for applications in rewritable media and recording devices. Here, an interesting design strategy of "Y‐shape" donor‐acceptor (D−A) type molecules for high‐contrast MRL materials was presented, based on substituted diphenylamine donor and planar acceptor. Interestingly, their D−A torsion angles are small in crystals but increased after ground, resulted in planar and twist intramolecular charge transfer (PICT and TICT) states, respectively. Therefore, high‐contrast MRL switching between weak blue (450 nm) fluorescence and bright yellow (552 nm) thermally activated delayed fluorescence (TADF) can be achieved for compound TXDO (4,4′‐dimethoxydiphenylamine donor), which photoluminescence quantum yield increased from 2.8 % to 54.7 % after ground. Most importantly, the two independent D−A conjugation dihedral angles are actually independent in the "Y‐shape" molecules. Especially for compound TXDT (4,4′‐di‐tert‐butyldiphenylamine donor), its crystal exhibited both PICT and TICT processes inside, resulted from the different dihedral angles of 11.8° and 35.5°, respectively. The TXDT crystal thus showed dual‐peak emission, including both TICT fluorescence and PICT room‐temperature phosphorescence. Therefore, this strategy of "Y‐shape" D−A type molecules provide a new approach to design advanced luminescent materials with mechano‐induced TADF feature, for high‐contrast MRL and single‐component white luminescence. [ABSTRACT FROM AUTHOR]

Regiodivergent [3+2] and [4+2] C−H annulation of imines and imidate esters with unsymmetrical alkynes has been achieved under Rh(III) catalysis. Further transformation of the aldehyde and TMS functionality on the indene products is also demonstrated. The current work highlights the alcohols‐directed multiple C−H annulation of imines and imidate esters, leading to diverse fused heterocycles. [ABSTRACT FROM AUTHOR]

The development of P(O)–heteroatom bond-forming reactions is of vital importance. However, previous methods all have their own limitations and drawbacks. Herein, we disclose an efficient, green, and direct photocatalytic phosphorylation of heteroatom nucleophiles under the irradiation of 12 W blue LEDs at room temperature using acid red 51 as the photocatalyst and eco-friendly air as the sole oxidant. The newly developed reaction shows broad substrate scope under halide-, base-, metal-, and additive-free conditions, providing practical and scalable access to phosphinic fluorides, phosphinic amides, phosphoramidates, and phosphinates. Mechanistic studies on the phosphorylation reaction suggest that a phosphorus-centered radical cation generated from the P(O)–H reagent via a photocatalytic single electron transfer (SET) might be the main reactive species involved in this transformation. [ABSTRACT FROM AUTHOR]

LiNi 0.6 Co 0.2 Mn 0.2 O 2 //graphite full cell, due to its high energy density as the most promising candidate for power batteries received increased attention, but the severe capacity loss under high-temperature conditions prevents their large-scale application. Here, glutaric anhydride (GA) and succinic anhydride (SA) as electrolyte additives are investigated to overcome the high-temperature problem of LiNi 0.6 Co 0.2 Mn 0.2 O 2 //graphite cells. Due to the unique film-forming features and high-temperature stability, the cells containing 0.5% GA and 0.5% SA can retain capacity retention of 91.2% and 92.4% stored at 60 ​°C for 15 days, corresponding to a negligible capacity loss of 4.6 and 0.8 mAh g-1 after 200 cycles, respectively. In addition, the lifespans of cells under 25 ​°C are also significantly extended by introducing GA and SA into the electrolytes. Electrochemical and spectroscopic techniques results indicate the full cell capacity loss is predominantly caused by the unstable anode solid electrolyte interphase (SEI) layer and a stable SEI film derived from GA and SA is formed on the graphite electrode surfaces. The SEI film can effectively inhibit the consumption of electrolytes and enhance the high-temperature performance of cells. This work paves a way for moderating high energy density cells' work under high-temperature operation by developing special anodic film-forming electrolyte additives. [ABSTRACT FROM AUTHOR]

The products are obtained in good yields and with moderate enantiomeric excess. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO)‐based polymer electrolytes with good flexibility and viscoelasticity, low interfacial resistance, and fabricating cost have caught worldwide attention, but their practical application is still hampered by the instability at high voltages and the low ionic conductivity (10−8 to 10−6 S cm−1). Herein, we rationally designed defects‐abundant Ga2O3 nanobricks as multifunctional fillers and constructed a PEO‐based organic‐inorganic electrolyte for lithium metal batteries. Due to the abundant O‐defects feature of Ga2O3 filler, this PEO‐based composite electrolyte not only broadens electrochemical stability window (over 5.3 V versus Li/Li+) but also in situ forms a Li–Ga alloy and solid electrolyte interphase (SEI) film during the cycling process causing a rapid diffusion of Li+ ions. The as‐prepared electrolyte has good interface compatibility with Li metal (without short‐circuiting over 500 h at 0.2 mA cm−2) and possesses superior high ionic conductivity. The assembled all‐solid‐state LiFePO4//Li cells attained an excellent cycling performance of 146 mAh g−1 over 100 cycles at 0.5 C. The XPS analysis reveals that Ga2O3 nanobricks can form in situ a Li−Ga alloy layer at the polymer/anode interface. This work shed a light on designing high ionic conductivity lithium alloys in the composite electrolyte, which can improve the electrochemical properties of PEO‐based polymer electrolytes. [ABSTRACT FROM AUTHOR]

Multiple-resonance (MR) thermal activated delayed fluorescence (TADF) emitters have attracted increasing attention in organic electroluminescence devices, owing to their superior quantum efficiency and narrowband emission for high color purity. However, MR-TADF materials often suffer from severe aggregation-caused quenching (ACQ) and efficiency roll-off problems due to their rigid planar structures and the lack of sufficient charge-transfer (CT) characters with inefficient reverse intersystem crossing (RISC). Herein, by attaching electron-rich triphenylamine (TPA) with twisted spatial conformation to the MR framework, two efficient narrowband MR-TADF emitters, namely BNCz-pTPA and BNCz-mTPA, are developed. The TPA substituent endows the new emitters with aggregation-induced emission enhancement (AIEE) for ACQ suppression. The unprecedented AIEE-MR-TADF emitters exhibit CT character in high-lying triplet excited states for faster RISC, while the locally-excited (LE) character of the first singlet excited state is retained for narrowband emission with high emission efficiency. An organic light-emitting diode (OLED) based on BNCz-pTPA exhibits a maximum external quantum efficiency of 27.3% with slow efficiency roll-off, demonstrating much higher performances than those of the BNCz-based OLED. This study may provide a simple but effective approach to constructing high-performance emitters for wide-color-gamut OLED displays. [ABSTRACT FROM AUTHOR]

Despite vast applications of macrocycles in supramolecular chemistry, achieving long‐lived emissions including room‐temperature phosphorescence (RTP) or thermally activated delayed fluorescence (TADF) for potential use still presents a great challenge. This work first reports hydrogen‐bonded (H‐bonded) macrocycles emitting RTP and TADF by introducing various donors onto the same aramide skeleton containing a rigid acceptor. The formation of charge transfer effectively enhances the photoluminescence efficiency. Aromatic carbonyl groups promote the intersystem crossing. The drastically reduced flexibility of chromophores fixed by the H‐bonded macrocyclic framework contributes to suppress the nonradiative decay to stabilize triplet excitons. Therefore, RTP and TADF are acquired by altering donors, and are systematically revealed by comparisons with control compounds and theoretical calculations. Finally, near white‐light emission (CIE, 0.30, 0.33) is realized via host–guest interactions. [ABSTRACT FROM AUTHOR]

The development of photoinduced luminescent radicals with dynamic emission color is still challenging. Herein we report a novel molecular radical system (TBIQ) that shows photo‐controllable luminescence, leading to a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ is decorated with steric‐demanding tertiary butyl groups that enable appropriate intermolecular interaction to make dynamic intermolecular coupling possible for controllable behaviors. We reveal that the helicenic pseudo‐planar conformation of TBIQ experiences a planarization process after light excitation, leading to more compactly stacked supermolecules and thus generating radicals via intermolecular charge transfer. The photo‐controllable luminescent radical system is employed for a high‐level information encryption application. This study may offer unique insight into molecular dynamic motion for optical manufacturing and broaden the scope of smart‐responsive materials for advanced applications. [ABSTRACT FROM AUTHOR]

The development of photoinduced luminescent radicals with dynamic emission color is still challenging. Herein we report a novel molecular radical system (TBIQ) that shows photo‐controllable luminescence, leading to a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ is decorated with steric‐demanding tertiary butyl groups that enable appropriate intermolecular interaction to make dynamic intermolecular coupling possible for controllable behaviors. We reveal that the helicenic pseudo‐planar conformation of TBIQ experiences a planarization process after light excitation, leading to more compactly stacked supermolecules and thus generating radicals via intermolecular charge transfer. The photo‐controllable luminescent radical system is employed for a high‐level information encryption application. This study may offer unique insight into molecular dynamic motion for optical manufacturing and broaden the scope of smart‐responsive materials for advanced applications. [ABSTRACT FROM AUTHOR]

Tuning the redox potential of commonly available photocatalyst to improve the catalytic performance or expand its scope for challenging synthetic conversions is an ongoing demand in synthetic chemistry. Herein, the excited state properties and redox potential of commercially available [Ru(bpy)3]2+ photocatalyst were tuned by modifying the structure of the bipyridine ligands with electron‐donating/withdrawing units. The visible‐light‐mediated photoredox phosphorylation of tertiary aliphatic amines was demonstrated under mild conditions. A series of cross‐dehydrogenative coupling reactions were performed employing the RuII complexes as photocatalyst giving the corresponding α‐aminophosphinoxides and α‐aminophosphonates via carbon‐phosphorus (C−P) bond formation. [ABSTRACT FROM AUTHOR]

The exploration of green C–H oxidation for the rapid construction of functional molecules, remains a permanent goal in synthetic chemistry. Herein, a traceless N-nitroso enabled oxidative Heck and amidation cascade was realized, leading to quinolinones that feature green oxidation and great functional group tolerance. The expedient construction of quinolinone containing pharmaceuticals including Flucarbril, Clostamide and Aripiprazole was achieved in a concise and environmentally friendly manner. [ABSTRACT FROM AUTHOR]

Narrowband emitting fluorophores exhibit immense potentials for organic light‐emitting diodes (OLEDs) with high color purity. However, it's still hard to simultaneously realize short‐wavelength ultraviolet (UV) or near ultraviolet emission (NUV) while maintaining a narrowed full width at half maximum (FWHM) value, and rare work focus on such challenging pursuit. Herein, an ingenious synthetic method was devised to achieve emitters with coplanar structure. 11‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl)indolo[3,2,1‐jk]carbazole (ICZ‐TAZ) was designed to realize narrowed UV emission both in photoluminescence (PL) and electroluminescence (EL) which benefited from the suppression of vibronic coupling. UV/NUV OLEDs based on ICZ‐TAZ achieve external quantum efficiency (EQE) maximums of 3.26 % peaks @ 388 nm and 4.02 % peaks @ 406 nm with small FWHM of 32 nm and 46 nm, respectively, corresponding with reduced efficiency roll‐off at luminance of 100 cd m−2. [ABSTRACT FROM AUTHOR]

Narrowband emitting fluorophores exhibit immense potentials for organic light‐emitting diodes (OLEDs) with high color purity. However, it's still hard to simultaneously realize short‐wavelength ultraviolet (UV) or near ultraviolet emission (NUV) while maintaining a narrowed full width at half maximum (FWHM) value, and rare work focus on such challenging pursuit. Herein, an ingenious synthetic method was devised to achieve emitters with coplanar structure. 11‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl)indolo[3,2,1‐jk]carbazole (ICZ‐TAZ) was designed to realize narrowed UV emission both in photoluminescence (PL) and electroluminescence (EL) which benefited from the suppression of vibronic coupling. UV/NUV OLEDs based on ICZ‐TAZ achieve external quantum efficiency (EQE) maximums of 3.26 % peaks @ 388 nm and 4.02 % peaks @ 406 nm with small FWHM of 32 nm and 46 nm, respectively, corresponding with reduced efficiency roll‐off at luminance of 100 cd m−2. [ABSTRACT FROM AUTHOR]

Compounds with through‐space charge transfer properties can be utilized as novel photocatalysts to drive efficient photopolymerization and lithography, as proposed by Jianzhang Zhao, Shaomin Ji et al. in their Research Article (e202402774). This strategy offers a new perspective for the design of photopolymerization systems...By Hui Liang; Xue Zhang; Manlin Lu; Xi Chen; Weiqiang Li; Shangru Li; Ming‐De Li; Jianzhang Zhao; Yanping Huo and Shaomin JiReported by Author; Author; Author; Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

[Display omitted] • A novel design of dual-core TADF emitters with through-space coupling is presented for organic electroluminescence. • The chiral emitters exhibited high PLQYs and the luminescence dissymmetry factor. • The efficient OLEDs show high external quantum efficiency with negligible efficiency roll-off at 1000 cd m−2. Through-space coupling (TSC) is the essential component of π-stacked systems and has promise in charge transport and electronic communication, which is of great significance for the construction of efficient and stable photoelectric devices. In this work, we demonstrate a chiral dual-core strategy for the design of high-performance organic circularly polarized emitters, which features of connecting two thermally activated delayed fluorescence (TADF) luminophores with chiral linkage that allows efficient TSC to occur. Using this strategy, a pair of dual-core enantiomers, R/S-DNKP, were designed and synthesized by linking two benzophenone derivatives with a 1,1′-bi-2-naphthol unit. Compared to the mono-core counterpart NKP, the dual-core emitters exhibited the photoluminescence quantum yields up to 94 %. Moreover, benefiting from their chiral helical folding configurations, the R/S-DNKP enantiomers exhibited the luminescence dissymmetry factor (| g lum |) value of +2.7 × 10−3 and −2.6 × 10−3 in doped films. Notably, the electroluminescence devices based on the R/S-DNKP enantiomers achieved external quantum efficiency values of 21.5 % and 19.7 % with little roll-off. It is believed that this molecular design strategy will pave new routes for the development of high-performance chiral emitters for future organic photonic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new 3D organic supramolecule constructed by unique halogen bonding and π–π interactions is obtained. • Dual phosphorescent emission mechanism of the supramolecule is explained. • This supramolecule shows highly stable UOP property that can be applied directly in extreme environments. Ultralong organic phosphorescence (UOP) materials have offered new exciting possibilities in the fields of photoelectric device, scintillators, anti-counterfeiting and bioprobe. However, pure organic phosphorescent materials inevitably suffer from rapid nonradiative transitions under oxygen, humidity, and high temperature, rending their phosphorescence is significantly quenched. Herein, a three-dimensional (3D) organic supramolecule (named SFIz) featuring UOP property was constructed successfully. Impressively, benefiting from the unique halogen bonding and π–π interactions, dual phosphorescent emission route of high energy state T 1 (Br···O interaction predominates) and low energy state T 1 * (π–π interaction predominates) was simultaneously realized. Furthermore, owing to the robust supramolecular structural characteristic, SFIz shows highly stable UOP property with remarkably thermal, force stimulus and water-resistant stabilities that can be applied directly in extreme environments such as high temperatures 453 K (180 °C), high pressure and humidity. This work not only provides a much needed solution for achieving highly stable UOP materials and promoting their applications in extreme environments, but also gives in-depth understanding of both UOP and dual phosphorescent emission mechanisms in a non-metallic organic molecule. [ABSTRACT FROM AUTHOR]

The utilization of triplet state excitons is important for the efficiency of organic light-emitting diodes (OLEDs). In this work, two isomers ( p -PIAnPO and m -PIAnPO) of anthracene-based derivatives with triphenylphosphine oxide (PO) and phenanthroimidazole (PI) in different positions were designed and synthesized. In particular, PO provides large spatial hindrance and promotes hole transport, and PI has excellent bipolar transport ability, which helps to balance carrier transport. The para- linkage ( p -PIAnPO) favors conjugation expansion and achieves high luminescence efficiencies, whereas the meta- linkage ( m -PIAnPO) provides a highly twisted molecular conformation, thus effectively interrupting conjugation and leading to deep-blue emission. These molecules exhibit excellent thermal stability and efficient electroluminescence properties. Non-doped OLEDs using p -PIAnPO and m -PIAnPO as the light-emitting layers achieve maximum external quantum efficiencies of 6.0% and 4.2% with the λ EL at 466 nm and 448 nm, corresponding to high exciton utilization efficiency (EUE) of 59%–88% and 54%–81%. In addition, p -PIAnPO-based OLEDs achieve an ultra-low efficiency roll-off of 1.7% at 1000 cd m−2. Theoretical calculations and experimental results show that the high EUE is mainly attributed to the high-lying reverse intersystem crossing from T 3 to S 1 namely hot exciton channel. • Large steric hindrance group PO inhibits exciton quenching. • PO improves hole transport performance. • An promises high luminescence efficiency. • OLED of p -PIAnPO with 466 nm emission and extremely low efficiency roll-off of 1.7% at 1000 cd m−2. [ABSTRACT FROM AUTHOR]

Organic luminophores of narrowband emission are considered a filter-less light resource, promising for high-resolution organic light-emitting diode (OLED) display technology. It is essentially feasible to achieve narrowband emission by manipulating the intrinsic structural relaxation and vibronic coupling in the excited state. On this basis, by the introduction of single bond-linked peripheral moieties of 4-methoxyphenyl into the benzo[c]benzo [7,8]quinolino[1,2,3-fg]acridine-7,11-dione (BAO) core, the resulting BAO-PMO is observed to exhibit better performance, achieving a full width at half-maximum (FWHM) of down to 27 nm/0.14 eV in toluene for the narrowest band compared with that of BAO (35 nm/0.20 eV). An effective strategy is thus proposed by the significant enhancement of the low-frequency vibronic coupling strength with simultaneous mitigation of the high-frequency ones to realize the control of structural relaxation. In consequence, the BAO-PMO based OLED device exhibits a narrowband green emission with an FWHM of 37 nm/0.18 eV. • Organic narrowband luminophores based on carbonyl-bridged triarylamine were shown. • The emission narrowing was achieved via vibronic coupling regulation of the excited-state configuration. • Doped OLEDs exhibit narrowband green emission with a full width at half-maximum of down to 37 nm. [ABSTRACT FROM AUTHOR]

We prepared an orthogonal compact electron‐donor (phenoxazine, PXZ)‐acceptor (naphthalimide, NI) dyad (NI‐PXZ), to study the photophysics of the thermally‐activated delayed fluorescence (TADF), which has a luminescence lifetime of 16.4 ns (99.2 %)/17.0 μs (0.80 %). A weak charge transfer (CT) absorption band was observed for the dyad, indicating non‐negligible electronic coupling between the donor and acceptor at the ground state. Femtosecond transient absorption spectroscopy shows a fast charge separation (CS) (ca. 2.02∼2.72 ps), the majority of the singlet CS state is short‐lived, especially in polar solvents (τCR = 10.3 ps in acetonitrile, vs. 1.83 ns in toluene, 7.81 ns in n‐hexane). Nanosecond transient absorption spectroscopy detects a long‐lived transient species in n‐hexane, which is with a mixed triplet local excited state (3LE) and charge separated state (3CS), the lifetime is 15.4 μs. In polar solvents, such as tetrahydrofuran and acetonitrile, a neat 3CS state was observed, whose lifetimes are 226 ns and 142 ns, respectively. Time‐resolved electron paramagnetic resonance (TREPR) spectra indicate the existence of strongly spin exchanged 3LE/3CT states, with the effective zero field splitting (ZFS) |D| and |E| parameters of 1484 MHz and 109 MHz, respectively, much smaller than that of the native 3NI state (2475 and 135 MHz). It is rare but solid experimental evidence that a closely‐lying 3LE state is crucial for occurrence of TADF and this 3LE state is an essential intermediate state to facilitate reverse intersystem crossing in TADF systems. [ABSTRACT FROM AUTHOR]

Mixed bromine/chlorine transformation products (Cl y Br x BPAs) of tetrabromobisphenol A (TBBPA) were recently identified for the first time in an electronic waste (e-waste) dismantling site. To determine whether these compounds can be used as specific molecular markers of e-waste dismantling activities, the environmental occurrences and distributions of TBBPA and its transformation products including debromination products (Br x BPAs) and Cl y Br x BPAs were analyzed in soil samples from three sites in China: Guiyu (an e-waste site), Qingyuan (a former e-waste site now mainly used for old wire and cable recycling), and Shouguang (a flame retardant production base). Levels of the target analytes in Guiyu were significantly higher than in Qingyuan and Shouguang. Br x BPAs and Cl y Br x BPAs were widely detected in Guiyu at concentrations between 1 and 4 orders of magnitude lower than their parent compound TBBPA. The highest concentration was found in an e-waste dismantling park, with lower concentrations in surrounding area. The levels of Cl y Br x BPAs in Qingyuan were much lower, indicating that the Cl y Br x BPAs may come from the processing of wires and cables, but not rule out the incubation on their own in soils. None of Cl y Br x BPAs were detected in Shouguang. Cl y Br x BPAs may thus be useful as specific molecular markers for determining the intensity of e-waste dismantling activities. [Display omitted] • TBBPA and its transformation products including Cl y Br x BPAs were analyzed. • Cl y Br x BPA concentrations were lower than Br x BPA and TBBPA. • Cl y Br x BPAs were observed in e-waste dismantling park and its surrounding area. • None Cl y Br x BPAs were detectable in a flame retardant production base area. • Cl y Br x BPAs can be used as specific molecular markers of e-waste dismantling industry. [ABSTRACT FROM AUTHOR]

Blue fluorescent materials are an essential part of commercial OLED displays and lightings. However, the market lacks highly efficient, short-emission wavelength blue fluorescent materials. Herein, two new blue fluorescent materials, SAFPI-3 and SAFPI-2, are developed based on a phenanthroimidazole derivative and spiro fluorene triphenylamine by replacing the substitution sites, which tactfully utilize the spatial configuration of the molecules to achieve higher external quantum efficiency and a shorter emission wavelength at the same time. Furthermore, the versatility of SAFPI-3 and SAFPI-2 can be demonstrated as non-doped emitters for blue OLEDs and as the hosts of yellow phosphorescent OLEDs, which have achieved a high external quantum efficiency of 23.98% with extremely low-efficiency roll-off. [Display omitted] • Two novel blue fluorescent isomers are developed. • SAFPI-3 -based non-doped OLED achieves a high EQE of 4.99% with EL emission peak at 432 nm. • OLED using SAFPI-3 as host obtains high EQE of 23.98% with negligible efficiency roll-off. [ABSTRACT FROM AUTHOR]

The development of anticancer therapy is significant to human health but remains a huge challenge. Photodynamic therapy (PDT), inducing the synergistic mitochondrial dysfunction in cancer cells is a promising approach but suffer from the low efficiency in hypoxic microenvironment and deep‐seated tumors. Herein, to improve the outcomes of PDT for cancer treatment, a series of red fluorophores consisting of dual‐cationic triphenylphosphonium‐alkylated pyridinium and (substituted) triphenylamine are prepared as organelle‐targeting antitumor photosensitizers (PSs) with aggregation‐induced emission characteristics. These PSs can selectively accumulate at the mitochondria or lysosomes of cancer cells with both dark‐ and photo‐cytotoxicity, making them possess excellent killing effect on cancer cells and efficient inhibition of tumor growth in living mice. This study brings about new insight into the development of powerful cancer treatment. [ABSTRACT FROM AUTHOR]

• The dual mode luminescence properties of β-spodumene (LiAlSi 2 O 6) are reported. • The dual mode emission intensity of the LAS:0.01Er3+ was improved by co-doping Yb3+ ions. • Green/red UC emissionsand NIR DC emission at 1535 nm were observed. • The possible mechanisms for the enhanced intensity of the dual emission is discussed. Novel Er3+ doped β-spodumene (LiAlSi 2 O 6) single host exhibits dual mode (down/upconversion) emissions, which was further enhanced (~10 times) by co-doping Yb3+ ions. [Display omitted] Fundamental understanding of the Stokes and anti-Stokes emissions in luminescence materials and their mechanism is very important for different technological applications. In this article, we report the dual mode, down/upconversion (DC/UC), luminescence in a LiAlSi 2 O 6 (β-spodumene) single host along with its mechanistic investigations. A series of emission tunable Li 1- x AlSi 2 O 6 : x Er3+ (LAS: x Er3+; 0 ≤ x ≤ 0.07) and Li 0.99- y AlSi 2 O 6 :0.01Er3+, y Yb3+ (LAS:0.01Er3+,yYb3+; 0.001 ≤ y ≤ 0.007) phosphor powders were prepared by solid state reaction method at 1300 °C. The formation of single-phase phosphors is verified by XRD technique and other structural properties are investigated by FT-IR, UV-Vis-NIR spectra. The phosphors produced NIR DC emission at 1535 nm (under 380 and 980 nm excitation) and an intense red UC emission at 655 nm (under both 980 and 808 nm excitations). The dual mode emission intensity of the LAS:0.01Er3+ is further improved by co-doping Yb3+ ions via energy transfer from Yb3+ to Er3+. The red UC emission intensity of LAS:0.01Er3+,0.005Yb3+ phosphor under 980 nm excitation is ~10 times stronger than the singly doped LAS:0.01Er3+ phosphor. In addition, the phosphors can also be efficiently excited by 808 nm laser and hence can be used for biological application since 808 nm NIR irradiation exhibits higher light penetration depth without inducing overheating. The mechanism of energy transfer from Yb3+ to Er3+ by considering different emission pathways viz: ground state absorption (GSA), excited state absorption (ESA), energy transfer upconversion (ETU), back energy transfer (BET) and cross relaxation (CR) are discussed in detail. Based on the dual mode emissions, the LAS: x Er3+ and LAS: x Er3+, y Yb3+ (x = 0.1 and 0.001 ≤ y ≤ 0.007) phosphors could be a potential candidate not only for the biological application as bio-probe but also as energy convertors for solid-state lighting, displays, and solar cell applications. [ABSTRACT FROM AUTHOR]

Modular construction of polyfunctional arenes from abundant feedstocks stands as an unremitting pursue in synthetic chemistry, accelerating the discovery of drugs and materials. Herein, using the multiple C–H activation strategy with versatile imidate esters, the expedient delivery of molecular libraries of densely functionalized sulfur-containing arenes was achieved, which enabled the concise construction of biologically active molecules, such as Bipenamol. [ABSTRACT FROM AUTHOR]