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We report a highly crystalline self‐assembled multilayer (SAMUL) that is fundamentally different from the conventional monolayer or disordered bilayer used for hole‐extraction in inverted perovskite solar cells (PSCs). The SAMUL can be easily formed on ITO substrate to establish better surface coverage to enhance the performance and stability of PSCs. A detailed structure‐property‐performance relationship of molecules used for SAMUL is established through a systematic study of their crystallinity, molecular packing, and hole‐transporting properties. These SAMULs are rationally optimized by varying their molecular structures and deposition methods through thermal evaporation or spin‐coating for fabricating PSCs. The CbzNaphPPA‐based SAMUL was chosen for fabricating inverted PSCs due to it exhibiting the highest crystallinity and hole mobility which is derived from the ordered H‐aggregation. This resulted in a remarkably high fill factor of 86.45 %, which enables a very impressive power conversion efficiency (PCE) of 26.07 % to be achieved along with excellent device stability (94 % of its initial PCE retained after continuous operation for 1200 h under 1‐sun irradiation at maximum power point at 65 °C). Additionally, a record‐high PCE of 23.50 % could be achieved by adopting a thermally evaporated SAMUL. This greatly simplifies and broadens the scope for SAM to be used for large‐area devices on diverse substrates. [ABSTRACT FROM AUTHOR]

The Chemical Communications journal, published by The Royal Society of Chemistry, features articles on various topics such as catalytic enantioselective construction, microbial transformation of heavy metals, and alkyne annulations. The journal also covers topics like photoswitches, ammonia adsorption, and selective photocatalytic CO2 reduction. Additionally, the journal includes articles on topics like thiazole synthesis, redox platforms, and lanthanide coordination polymers. The publication aims to uncover new possibilities and provide fundamental answers to scientific questions. [Extracted from the article]

A novel "Ring-expansion" strategy is proposed to optimize traditional host molecular structures, featuring a rigid molecular skeleton and excellent transport of carriers. Consequently, the two novel host materials facilitate the fabrication of efficient phosphorescent OLEDs with suppressed efficiency roll-off compared to OLEDs based on the conventional host material (mCP). [ABSTRACT FROM AUTHOR]

Carbazole derivatives are vital in medicinal and materials chemistry, yet accessing diverse substitutions remains challenging. Here, we introduce a regioselective approach for C1 and C8 alkynylation of carbazoles via palladium‐catalyzed C−H activation. This method provides a direct route to mono‐ and di‐alkynylated derivatives, addressing the scarcity of alkynylated carbazole‐based materials. Our study broadens the synthetic toolbox for carbazole functionalization, offering potential applications in optoelectronics, bio‐imaging, and beyond, while contributing to developing sustainable C−H activation methodologies. [ABSTRACT FROM AUTHOR]

ABSTRACT Dye‐sensitized solar cells (DSSCs) have garnered significant attention as a promising photovoltaic technology because of their low cost and simplicity. However, the development of efficient organic sensitizers remains a challenge. In this study, we report the synthesis and characterization of two novel organic co‐sensitizers, CD‐1 and TD‐2, based on a thiazolidine core structure and the incorporation of carbazole and triphenylamine donor moieties, respectively. Co‐sensitizers were designed to leverage the strong electron‐donating abilities of these donors to facilitate efficient light‐harvesting and charge‐transfer processes. In‐depth analyses of the spectroscopic and electrochemical properties provided insights into the characteristics of TD‐2 compared with those of CD‐1. TD‐2 displayed a wider range of absorption wavelengths, a narrower energy gap (2.19 eV), and a higher energy level for its (HOMO) than that of CD‐1. These distinctions are attributed to the enhanced capacity of TD‐2 to donate electrons and the elongated π‐conjugation of the triphenylamine component. Upon sensitization, the TD‐2 scored efficiency reached 5.10% and co‐sensitized with N719 dye achieved the highest efficiency, reaching 7.95%. Both sensitizers increased the efficiency of N719 by co‐sensitization (TD‐2 + N719), with an efficiency higher than 15% compared with N719. [ABSTRACT FROM AUTHOR]

The document is the contents list for the journal "Chemical Communications" published in 2024. It includes various articles on topics such as precision photodynamic therapy, materials design for polymers, efficient electrocatalysts, and molecular perovskites. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document provides a comprehensive overview of the articles included in the journal issue. [Extracted from the article]

For the first time, we present the detailed synthesis, photophysical, electrochemical, host–guest and charge transport properties of spiro[fluorene-9,9′-xanthene] (SFX) and carbazole macrocycle SPS-NR-02. The electron and hole transport values measured using the space charge limited current (SCLC) method resulted in ambipolar charge transport with an electron to hole mobility ratio of 0.39. [ABSTRACT FROM AUTHOR]

A series of six DPP-based organic small molecule photovoltaic donor materials were designed and synthesized successfully. The targeted structural design and regulation of the materials were carried out in three steps. Firstly, the introduction of a π-bridge in the molecule enhances the intramolecular charge transfer (ICT) effect and improves the short-circuit current (Jsc) of the device. Secondly, different end groups were introduced to adjust the energy levels of molecules, to obtain more matching donor materials for acceptor materials. Finally, the molecular configuration was adjusted to meet the requirements of increasing the open circuit voltage (Voc). It is worth mentioning that for the end group regulation strategy, a small molecule donor was synthesized, in which fluorene-capped triarylamine as the electron-donating unit provided a reference for the future development of related donor materials. To our knowledge, the selection of triphenylamine and phenyl-carbazole as central nuclei for double-armed small molecule donors has been rarely reported. In this work, triphenylamine and phenyl-carbazole were used as the central nuclei of the A–π–D–π–A type molecular configuration, resulting in lower HOMO energy levels and higher Voc. As a result, without further optimization of the devices, the power conversion efficiency (PCE) of the photovoltaic device based on (DPP)2TPA was more than three times that of a previously reported device based on TPA-DPP-TPA, and the PCE of the device based on (DPP)2PCZ was more than twice that of a previously reported device based on SM1. Our work demonstrates that optimization of photovoltaic performance can be achieved through rational structural design and configuration regulation of the photovoltaic material, which provides important guidance for the development of novel photovoltaic materials in the future. [ABSTRACT FROM AUTHOR]

Conducting polymers are emerging as promising alternatives to rare and expensive platinum for counter electrodes in dye-sensitized solar cells; due to their ease of synthesis, they can be chemically tuned and are suitable for roll-to-roll production. Among these, poly (3,4-ethylenedioxythiophene) (PEDOT)-based counter electrodes have shown leading photovoltaic performance. However, certain conductivity issues remain that affect the effectiveness of these counter electrodes. In this study, we present an electropolymerized PEDOT and poly(N-alkylated-carbazole) copolymer as an efficient electrocatalyst for the reduction in I 3 − in dye-sensitized solar cells. Copolymerization with N-alkylated carbazoles significantly increases the conductivity of the polymer film and facilitates rapid charge transport at the interface between the polymer electrode and the electrolyte. The length of the alkyl substituents also plays a crucial role in this improvement. Electrochemical analysis showed a reduction in charge transport resistance from 3.31 Ω·cm2 for PEDOT to 2.26 Ω·cm2 for the PEDOT:poly(N-octylcarbazole) copolymer, which is almost half the resistance of a platinum-based counter electrode (4.12 Ω·cm2). Photovoltaic measurements showed that the solar cell with the PEDOT:poly(N-octylcarbazole) counter electrode achieved an efficiency of 8.88%, outperforming both PEDOT (7.90%) and platinum-based devices (7.57%). [ABSTRACT FROM AUTHOR]

Already known molecules which exhibit good electrochemiluminescence (ECL) efficiencies and high photoluminescence quantum yields (PLQY) have been structurally modified in order to increase their performance. The followed strategy is to stiffen the structures to limit the rotational and vibrational freedom degrees and favour radiative decay processes once excited. Molecules under investigation consist of donor‐acceptor systems in which the acceptor fraction is a benzonitrile with an imidazole in para position, while the donor fraction consists of four diphenylamine (NPh2) or 3,6‐di(tert‐butyl)‐9H‐carbazole (t‐BuCz) groups in the remaining positions on the central benzene ring. Therefore, in order to stiffen these systems and restrict the intramolecular rotations (RIR), the imidazole in the para position has been replaced with more extended π‐systems, i. e., benzimidazole and phenanthro[9,10‐d]imidazole. The restriction of the intramolecular rotation can be clearly observed by 1H NMR analysis. We expected to observe an increase in ECL efficiency and PLQY with the rigidity. Surprisingly, we observed a generally opposite trend: molecules with the smallest imidazole fraction showed the best performance in ECL and higher PLQY. Notably, NPh2 derivatives with benzimidazole and phenanthro[9,10‐d]imidazole showed an hypsochromic shift of the emission spectra with concomitant increase of the PLQY as the solvent polarity increases. [ABSTRACT FROM AUTHOR]

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 0.89 and 0.90 for the Ir(III) complexes Cz‐dfppy‐CN and tBuCz‐dfppy‐CN, respectively. Analysis of the single crystal structure and density functional theory (DFT) calculation results revealed an inherent correlation between molecular aspect ratio and EDO. Utilizing the newly obtained emitters, the blue OLED devices demonstrated exceptional performance, achieving a maximum EQE of 30.7% at a Commission International de l'Eclairage (CIE) coordinate of (0.140, 0.148). Optical transfer matrix‐based simulations confirmed a maximum outcoupling efficiency of 35% due to improved EDO. Finally, the tandem OLED and hyper‐OLED devices exhibited a maximum EQE of 44.2% and 31.6%, respectively, together with good device stability. This rational molecular design provides straightforward guidelines to reach highly efficient and stable saturated blue emission. [ABSTRACT FROM AUTHOR]

Developing cost-effective, high-efficiency, and stable hole transporting materials (HTMs) is crucial for replacing traditional spiro-OMeTAD in perovskite solar cells (PSCs) and achieving sustainable solar energy solutions. This work presents two novel air-stable HTMs based on a spiro[fluorene-9,9′-xanthene] (SFX) core functionalized with N-methylcarbazole (XC2-M) and N-hexylcarbazole (XC2-H) rings. These HTMs were synthesized via a straightforward, three-step process with good overall yields (∼40%) and low production costs. To further reduce device cost, carbon back electrodes were employed. The resulting PSCs, with a structure of FTO/SnO2/Cs0.05FA0.73MA0.22Pb(I0.77Br0.23)3/HTM/C achieved power conversion efficiencies (PCEs) of 13.5% (XC2-M) and 10.2% (XC2-H), comparable to the reference spiro-OMeTAD device (12.2%). The choice of alkyl chain on the HTM significantly impacts film morphology and device stability. The XC2-H device exhibited exceptional long-term stability, retaining approximately 90% of its initial PCE after 720 h of storage in 30–40% humidity air without encapsulation. This surpasses the performance of both the spiro-OMeTAD (55% retention) and XC2-M (68% retention) devices. The superior stability of XC2-H is attributed to its highly hydrophobic nature and the formation of a compact, smooth film due to interdigitation of the hexyl chains. The straightforward synthesis of XC2-H from commercially available materials offers a promising approach for large-scale PSC production. [ABSTRACT FROM AUTHOR]

Organic phosphorescent materials are excellent candidates for use in tumor imaging. However, a systematic comparison of the effects of the intensity, lifetime, and wavelength of phosphorescent emissions on bioimaging performance has not yet been undertaken. In addition, there have been few reports on organic phosphorescent materials that specifically distinguish tumors from normal tissues. This study addresses these gaps and reveals that longer lifetimes effectively increase the signal intensity, whereas longer wavelengths enhance the penetration depth. Conversely, a strong emission intensity with a short lifetime does not necessarily yield robust imaging signals. Building upon these findings, an organo‐phosphorescent material with a lifetime of 0.94 s was designed for tumor imaging. Remarkably, the phosphorescent signals of various organic nanoparticles are nearly extinguished in blood‐rich organs because of the quenching effect of iron ions. Moreover, for the first time, we demonstrated that iron ions universally quench the phosphorescence of organic room‐temperature phosphorescent materials, which is an inherent property of such substances. Leveraging this property, both the normal liver and hepatitis tissues exhibit negligible phosphorescent signals, whereas liver tumors display intense phosphorescence. Therefore, phosphorescent materials, unlike chemiluminescent or fluorescent materials, can exploit this unique inherent property to selectively distinguish liver tumor tissues from normal tissues without additional modifications or treatments. [ABSTRACT FROM AUTHOR]

The combination of a microcavity and a microsphere has been proposed in this work to manipulate light in terms of emission wavelength and propagation direction. A microcavity with a layer of molecular photoswitch between two one-dimensional photonic crystals of polyvinyl carbazole and cellulose acetate has been designed. To tune the microcavity, the molecular photoswitch has been excited taking into account its cyclization upon irradiation at 313 nm and its cycloreversion at 450 nm. In this way, the emission peak of the microcavity switches from 508.5 nm to 525 nm. A polystyrene microsphere with a radius of 1 μ m is placed near the microcavity. With the detector at an angle of 8°, the emission at 525 nm is 1.73 times higher with respect to the emission at 508.5 nm, while at 10.8°, the emission at 508.5 nm is 1.45 times higher with respect to the emission at 525 nm. The value of these findings is that they offer the experimentalists a ready means to compare the optical data of these types of composites with theory. [ABSTRACT FROM AUTHOR]

Polycyclic heterocycles are the most common and critical structural motifs found in a variety of natural products, medicines, fertilizers, and advanced materials. Because of their widespread use in biologically active compounds and material chemistry, functionalised dibenzo heterocyclic compounds, especially dibenzofuran, dibenzothiophene, and carbazole derivatives, garnered much attention over time. Scientists are especially interested in elucidating more efficient techniques for developing these industrially essential compounds. Dibenzo‐fused heterocycles can rapidly be synthesised using highly efficient transition metal‐catalysed strategies as well as by economic metal‐free reaction conditions. This review includes a detailed overview of the most recent significant synthetic techniques, both metal‐catalysed and metal‐free, to produce these industrially significant and medicinally important dibenzo‐fused heterocycles. [ABSTRACT FROM AUTHOR]

Migration pathways and distances of the oils in reservoir are thought to affect the distribution of pyrrolic compounds such as carbazole, its alkyl derivatives (alkylated carbazoles) and benzocarbazoles, although other factors, including maturity and depositional environments may also affect the distribution of these organic nitrogen compounds. In this study, 14 oil samples produced from conventional reservoirs in Pauls Valley, south Oklahoma were investigated using organic geochemical techniques. The sterane and hopane fingerprints suggest that most of the oils were sourced from the Devonian Woodford shale. Maturity parameters consistently indicate that the maturity level of the studied samples are all of similar maturity (Rc = ∼0.7%), suggesting the distribution of the organic nitrogen organic compounds is possibly reflecting variations in relative migration distances. The distribution of alkylcarbazoles revealed a preferential enrichment during migration, with the nitrogen-shielded alkylcarbazole tending to be enriched relative to the nitrogen-semi-shielded alkylcarbozoles particularly in oils produced close to the Arbuckle uplift to the east. Correspondingly, another family of pyrrolic compounds, benzocarbazoles, whose distributions also indicated that the Pauls Valley Woodford oils came from deeper part of the Anadarko Basin as the benzo-[a]/([a]+[c])-carbazole ratios decrease eastwards. In more specific migration systems, although the pyrrolic compound indicators are potentially disturbed by the structural complexes, the general migration directions suggest that the studied oils in Pauls Valley Hunton uplift were sourced from the deep basin area, and migrate upwards in porous sediments due to the buoyancy. This study investigates the feasibility of using pyrrolic compounds to estimate relative migration distances and will aid in the interpretation of migration history by using the distribution of carbazole, alkylated carbazoles, benzocarbazoles isomers in the Anadarko and Ardmore Basin petroleum systems. [ABSTRACT FROM AUTHOR]

Cancer, a complex group of heterogeneous diseases characterized by the uncontrolled growth and the capability to invade nearby tissues and organs, represents a severe threat to public health worldwide. Over 100 chemotherapeutics have been approved for clinical cancer therapy, but the goal of eradicating cancer remains elusive mainly due to the continuous emergency of drug resistance, necessitating the development of novel anticancer chemotherapeutics. Indoles and carbazoles, contain a benzo[b]pyrrole moiety, are ubiquitous in nature and possess remarkable structural, and anticancer mechanistic diversity, whereas sulfonamides demonstrated potent anticancer efficacy through multiple modes of action, inclusive of apoptosis induction, autophagy regulation, and cell cycle disruption. Accordingly, indole/carbazole and sulfonamide constitute valuable anticancer pharmacophores, and rational hybridization of sulfonamide and indole/carbazole holds a significant functionality in discovery of new anticancer agents. In this review, we summed up the recent advances of sulfonamide-indole/carbazole hybrids with anticancer potential and elucidated the structure-activity relationships as well as mechanisms of action, covering articles published from 2020 onwards, to pave the way for developing more effective anticancer candidates. [ABSTRACT FROM AUTHOR]

A series of fluorescent carbazole‐coumarins exhibiting good photoluminescence quantum yields and thermally activated delayed fluorescence (TADF) properties have been designed and synthetized using computer‐aided density functional theory calculations. The TADF characteristics of the carbazole‐coumarins were systematically explored both in solution and in the solid state, utilizing poly(methyl methacrylate) (PMMA) as a matrix. The study revealed that the introduction of carbazole units onto the coumarin benzene ring led to compounds with thermally induced reverse intersystem crossing and delayed fluorescence. The study further demonstrated the potential utility of these compounds in practical applications by incorporating them into a Cmr‐PMMA‐based sensor for molecular oxygen detection. The resulting sensor exhibited promising performance, highlighting the adaptability and efficacy of the synthesized TADF‐carbazole‐coumarin compounds for reversible molecular oxygen sensing. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis and characterization of new diamines with carbazole and imidazole pendant groups, leading to the development of polyamides and polyimides. The polyamides were synthesized by reacting diamines with carboxylic acids using polyamidation and phosphorylation techniques, while polyimides were prepared by combining diamines and dianhydrides. FT–IR and 1H-NMR analyses were used for comprehensive structural elucidation of diamine, polyamides, and polyimides. The polyamides and polyimides with inherent viscosities ranging from 0.48 to 0.64 dL/g showed notable thermal stability. The T10% weight loss values were between 287 and 340 °C for polyamides and 321–381 °C for polyimides. The percentage of char residue varied between 33 and 56% at 700 °C. Additionally, the maximum emission wavelengths of polymers ranged from 410 to 436 nm. The presence of bulky carbazole and imidazole pendant groups facilitated the good solubility of the polymers in common organic solvents. The antibacterial properties of synthesized polyamides and polyimides against both Gram-negative and Gram-positive bacteria and fungi were investigated. [ABSTRACT FROM AUTHOR]

The carbazole-3-carbaldehyde 2, produced by N-ethyl carbazole via Vilsmeier-Haack reaction, was subjected to Dakin type oxidation with H2O2 and H2SO4 in methanol to produce the carbazole-3-ol 3. The reaction of 3 with a range of commercially available α-haloketones 4a–f in the presence of Al2O3 as catalyst in xylene led to their regio-selective cyclization to afford the furo[2,3-c]carbazoles 5a–f. Identification of the furo[2,3-c]carbazoles 5a–f were performed through 1H NMR,13C NMR, FT-IR and high resolution mass spectrometry. Single crystal X-ray diffraction analysis was employed to further confirm the structures of the some of the targeted compounds. In vitro antidiabetic activities of the newly synthesized furocarbazoles 5a–e were investigated utilizing α-glucosidase and α-amylase enzymes. The biological evaluation revealed the obvious efficiencies of the targeted molecules toward the α-glucosidase enzyme inhibition with the potent IC50 values compared to the standard acarbose. In the case of α-glucosidase inhibition, the furo[2,3-c]carbazoles chloro substituted 5c and nitro substituted 5f were found to be more potent than acarbose with the values of 215.0 and 162.70 μM, respectively. On the other hand, the compound 5f was found to be only promising candidate for α-amylase enzyme but not as effective as the standard acarbose. [ABSTRACT FROM AUTHOR]

The present article provides a personalized account on CH-arylation reactions employed for the synthesis of heterocycles. The presence of a nitro group allowed for direct and regioselective CH-arylations of pyrazoles, imidazoles, indoles and a variety of purine analogues. Direct CH-arylations without the presence of an activating nitro-group were employed for inter- and intramolecular reactions of purine derivatives, which allowed for the synthesis of a great variety of polycyclic systems. Domino C–N coupling / hydroamination / CH-activation reactions of diarylacetylenes with anilines allowed for the synthesis of polycondensated N -heterocycles. Products include indolo- and azaindolo[1,2- f ]phenanthridines, quinolino[3′,4′:4,5]pyrrolo[1,2- f ]phenanthridines, pyrimido[5′,4′:4,5]pyrrolo[1,2- f ]phenanthridines, and benzothieno[2′,3′:4,5]pyrrolo[1,2- f ]phenanthridines. The reaction of N -heterocycles, such as indoles, with 1,1-difluoroalkenes resulted in a twofold addition-elimination reaction to give 1,1-diaminoalkenes, which were transformed by CH-arylation into various polycondensated heterocycles, such as indoloisoquinolines, thienoindolizines, oxepines and helicenes. Pyridofluoranthenes, diindenopyrene and azadiindenopyrenes were prepared by a combination of Pd-catalyzed cross-coupling reactions with acid-mediated cycloisomerizations and Pd-catalyzed intramolecular CH-arylations. Bis(carbazoles), benzodithiazoles, benzodithiophenes and 2,5-diarylpyrroles were prepared by inter- and intramolecular CH-arylation reactions. [ABSTRACT FROM AUTHOR]

Fused polycyclic aromatic compounds containing carbazole and diazapyrene skeletons as electron donors and acceptors, respectively, were synthesized in a few steps from readily accessible starting materials. The incorporation of diazapyrene units into the polycyclic compounds resulted in significant bathochromic shifts in their absorption and emission bands compared to those of the corresponding carbazole derivatives. Electrochemical measurements and density functional theory calculations were performed to gain further insight into their electronic properties. Our findings demonstrate that the incorporation of nitrogen atoms and substituents, as well as the different topologies of the fused‐ring system, exert a profound effect on the electronic properties of the polycyclic compounds. [ABSTRACT FROM AUTHOR]

Organic photoresponsive materials, which change their physical properties upon irradiation with light, are attracting tremendous scientific attention, as they offer a flexible and sustainable platform for developing various optoelectronic devices. In this work, photoinduced magnetization switching in two carbazole‐functionalized organic molecules, (9H‐carbazol‐9‐yl)(4‐chlorophenyl)methanone (ClPhCz) and (9H‐carbazol‐9‐yl)(2,4‐dichlorophenyl)methanone (DClPhCz) is reported for the first time. It was found that stabilization of the triplet excited state in those molecules is long enough for a net change in magnetic moment to be detected with a SQUID magnetometer. The change in magnetic moment upon excitation with a blue light laser was larger in ClPhCz, remaining high upon repeating the photoirradiation. In contrast, DClPhCz exhibited a smaller magnetic response, which gradually decreased upon repeating the experiment. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have attracted growing interests as new material platform for a range of applications. In this study, a triazine‐carbazole‐based covalent organic framework (COF‐TCZ) was designed as highly porous material with conjugated donor‐acceptor networks, and feasibly synthesized by the Schiff condensation of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tr ianiline (TAPB) and 9‐(4‐formylphenyl)‐9H‐carbazole‐3,6‐dicarbaldehyde (CZTA) under the solvothermal condition. Considering the effect of linkage, the imine‐linked COF‐TCZ was further oxidized to obtain an amide‐linked covalent organic framework (COF‐TCZ‐O). The as‐synthesized COFs show high crystallinity, good thermal and chemical stability, and excellent photoactive properties. Two π‐conjugated triazine‐carbazole‐based COFs with tunable linkages are beneficial for light‐harvesting capacity and charge separation efficiency, which are empolyed as photocatalysts for the oxidation reaction of N‐aryltetrahydroisoquinoline. The COFs catalyst systems exhibit the outstanding photocatalytic performance with high conversion, photostability and recyclability. Photoelectrochemical tests were employed to examine the behavior of photogenerated charge carriers in photo‐illumination system. The control experiments provide further insights into the nature of photocatalysis. In addition, the current research also provided a valuable approach for developing photofunctional COFs to meet challenge in achieving the great potential of COFs materials in organic conversion. [ABSTRACT FROM AUTHOR]

We have accomplished a unified strategy to achieve the structurally intriguing indolosesquiterpene alkaloids with diverse biological activity, xiamycin A (1a), xiamycin A methyl ester (1b) and oridamycins A (2a), and B (2b), which possesses a complex 6/6/6/5/6-fused pentacyclic skeleton bearing a carbazole moiety fused with a highly functionalized trans-decalin motif. Lewis acid-mediated epoxy-ene cyclization establishes the required pentacyclic scaffold with the installation of the four contiguous stereogenic centers. Further oxidative cleavage of the vinyl functionality, followed by successive functional group interconversions, completed the total synthesis of the indolosesquiterpene alkaloids. [ABSTRACT FROM AUTHOR]

Murraya koenigii leaves are widely used as a spice and also have several biological activities. The major active constituents are carbazole alkaloids. Quantitation by HPLC or HPTLC requires pure marker compounds, whereas nuclear magnetic resonance spectroscopy can be used as a quantitative technique without the requirement of a pure marker compound. An alkaloid-rich fraction was prepared from the leaves and a validated qNMR method was developed for the quantitation of nine carbazole alkaloids, namely mahanimbine, girinimbine, koenimbine, koenine, kurrayam, mukonicine, isomahanimbine, euchristine B and bismahanine. One of the major compounds, koenimbine, was isolated and quantified by HPTLC to compare the results. The results obtained by qNMR were compared with the reported yields of these compounds. [ABSTRACT FROM AUTHOR]

Based on the strong binding properties of hydroxylamino-1,3,5-triazine (BHT) for hard metal ions, a novel spectroscopically labelled triazine-hydroxylaminato ligand, N,N′-(6-(9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(N-methylhydroxylamine) (H2cbht), was synthesized. Reaction of H2cbht with FeIII, VV and UVI resulted in the synthesis of [UVIO2(cbht)(DMF)(MeOH)], 1, (PPh4)2([UVIO2(Hcbht)2]·2[UVIO2(Hcbht)(cbht)]), 2, (PPh4)2[(UVIO2)3(μ-cbht)2(cbht)2], 3, Na[VVO2(cbht)], 4, and (PPh4)[FeIII(cbht)2], 5. The complexes were characterized by X-ray crystallography showing strong chelation of the metal ions with the BHT chelating moiety H2cbht. The DMSO/DMF solutions of the complexes were characterized by NMR, UV-vis and electrochemistry, confirming the high affinity of H2cbht for FeIII, VV or UVI. The luminescence properties of the carbazole group were retained in the BHT adduct of the H2cbht ligand. Interaction of the metal ions with H2cbht resulted in quenching of the luminescence of H2cbht. Stern–Volmer plots of luminescence vs. concentration of the metal ions are linear and suitable for the determination of the concentration of metal ions in nM range concentrations. Benesi–Hildebrand plots show that the metal-to-ligand ratio is 1 : 1 while the formation of the metal complexes exhibits high association constants. [ABSTRACT FROM AUTHOR]

Organic afterglow can be generated from persistent thermally activated delayed fluorescence (pTADF) or organic ultralong room temperature phosphorescence (OURTP), but the pTADF plus OURTP type organic afterglow is challenging to achieve, especially for the color‐tunable and high‐temperature ones. Herein, an accessible strategy toward such dual‐mode afterglow is presented by doping the indolo[3,2‐b]carbazole (ICZ‐p1) into polymethyl methacrylate (PMMA). The resulting films exhibit photo‐activated afterglow with two persistent emission peaks of ca. 435 and 497 nm. Impressively, their longest lifetimes respectively reach to 2.28 and 2.47 s at 298 K, along with 0.32 and 0.42 s at 360 K, enabling the afterglow at room and high temperature. Experimental and theoretical results reveal that the photo‐activated afterglow is associated with the elimination of molecular O2 inside film and composed by the pTADF with multi‐resonance (MR) effect and OURTP. By altering the temperature from 77 to 358 K, the color‐tunable afterglows of green and blue are harvested at such temperature ranges. Benefiting from the multi‐resonance thermally activated delayed fluorescence (MRTADF) characteristics, this emitter can release narrow‐band electroluminescence. Consequently, the results obtained here may offer important references for chasing MRTADF plus OURTP‐type dual‐mode organic afterglow showing color‐tunable and high‐temperature features. [ABSTRACT FROM AUTHOR]

Background: Carbazole-based molecules containing thiosemicarbazide functional groups are recognized for their diverse biological activities, particularly in enhancing therapeutic anticancer effects through inhibiting crucial pathways. These derivatives also exhibit noteworthy antioxidant properties. Objectives: This study aims to synthesize, characterize, and evaluate the antioxidant and anticancer activities of 18 novel carbazole derivatives. Methods: The radical scavenging capabilities of the compounds were assessed using the 2,2-diphenyl-1-picrylhydrazyl assay. Antiproliferative activities were evaluated on MCF-7 cancer cell lines through viability assays. Additionally, the modulation of the PI3K/Akt/mTOR pathway, apoptosis/necrosis induction, and cell cycle analysis were conducted for the most promising anticancer agents. Results: nine compounds showed potent antioxidant activities with IC50 values lower than the positive control acarbose, with compounds 4 h and 4y exhibiting the highest potency (IC50 values of 0.73 and 0.38 µM, respectively). Furthermore, compounds 4o and 4r displayed significant anticancer effects, with IC50 values of 2.02 and 4.99 µM, respectively. Compound 4o, in particular, exhibited promising activity by targeting the PI3K/Akt/mTOR signaling pathway, inhibiting tumor survival, inducing apoptosis, and causing cell cycle arrest in MCF-7 cell lines. Furthermore, compound 4o was showed significant antimicrobial activities against S. aureus and E. coli, and antifungal effect against C. albicans. Its potential to overcome drug resistance through this pathway inhibition highlights its promise as an anticancer agent. Molecular docking simulations supported these findings, revealing favorable binding profiles and interactions within the active sites of the enzymes PI3K, AKT1, and mTOR. Moreover, assessing the druggability of the newly synthesized thiosemicarbazide derivatives demonstrated optimal physicochemical properties, further endorsing their potential as drug candidates. [ABSTRACT FROM AUTHOR]

A profitable approach for improving the stability of n‐i‐p planar perovskite solar cell (PSC) is developing dopant‐free hole transport materials (HTMs) with desirable intrinsic charge transport properties. In this work, by adopting a metal‐free catalytic intramolecular C─C coupling reaction, a carbazole dimer‐based fused‐ring is synthesized, and further developed a small molecular dopant‐free HTM abbreviated as NCz‐DM with appropriate energy level, excellent hole transport and film formation properties. Applied in n‐i‐p planar PSC, an impressive power conversion efficiency (PCE) of 24.0% is achieved, together with enhanced humidity, thermal and light stability, which is among the high level of ever‐reported results for PSCs utilizing small molecular dopant‐free HTM. [ABSTRACT FROM AUTHOR]

A dyad Carbazolyl‐bis(hydrazinobenzothiazole) was designed to form a symmetrical structure that containing two‐arm active binding sites facilitates coordination with Hg2+ ion. This sensor has imparted a colorimetric and fluorometric changes in presence of Hg2+ ions. The ligand showed a selective blue shift in presence of Hg2+even in co‐existence with heavy metal ions with luminescence change from colorless to blue and colorless to green under day light. Enhanced Intramolecular charge transfer process is responsible for fluorescence transformation when ligand interacts with Hg2+ ion. The emission spectra showed a ratiometric response to increasing addition of Hg2+ ions. The sensor is capable of detecting above the lower concentration of 6.8025×10−8 M. The fluorescence efficiency of CBT‐2 with Hg2+ ion is quite stable under different co‐metal ions and wide range of pH 6 to 9. The sensor CBT‐2 forms a 1 : 1 stoichiometric complex with Hg2+ ions and the binding nature is confirmed from the 1H‐NMR, FTIR, and mass spectroscopic studies. The sensor CBT‐2 and its Hg2+ complex possess good binding nature to protein in Bovine Serum Albumin which could be good in biological applications. Additionally, wedevelop a practical application in real water sample analysis and electrochemical detection via oxidation potential discrimination. [ABSTRACT FROM AUTHOR]

Two new p‐type molecules, namely TAT‐TY3 and TAT‐TY4, featuring triazatruxene endcaps and carbazole π‐bridges, were synthesized. The photophysical and electrochemical properties of synthesized materials were comparatively investigated based on their 2,7‐ and 3,6‐carbazole conjugation pathways. Optical characterizations revealed the impact of non‐bonding electron delocalization of triazatruxene through carbazole moieties, resulting in a significant increase in absorption intensity corresponding to n‐π* energy transitions and a red shift of triazatruxene moieties. Consequently, the optical band gaps of TAT‐TY3 and TAT‐TY4 were measured at 3.0 and 3.2 eV, respectively. Moreover, the molecules′ first oxidation potentials exhibited a drastic difference due to the electrochemical behavior of 2,7‐ and 3,6‐carbazole moieties. The highest occupied molecular orbital (HOMO) level for TAT‐TY3 was measured to be −5.02 eV, while for TAT‐TY4, it was measured as −4.67 eV. Hole‐extraction properties were explored using steady‐state and time‐resolved photoluminescence spectroscopy, revealing enhanced charge transfer between the TAT‐TY3/Perovskite interface due to the better alignment of HOMO energy levels. The photovoltaic performances of the hole‐transporting materials (HTMs) were successfully characterized in triple‐cation perovskite solar cells and efficiencies of up to 17.9 %, 16.2 %, and 9.8 % were achieved for Spiro‐OMeTAD, TAT‐TY3, and TAT‐TY4, respectively. [ABSTRACT FROM AUTHOR]

A novel carbazole compound, named 1-(9-ethyl-9H-carbazol-3-yl)-3-phenylurea (Cpu) was synthesized and its binding properties with protease enzymes (pepsin and trypsin) has been examined by steady-state fluorescence measurements, UV/vis absorption, infrared (FT-IR) and circular dicroism (CD) spectroscopies and also computational methods. The fluorescence experimental results indicated that the quenching mechanism of enzyme by Cpu is static process. The thermodynamic parameters (both negative ΔH/ΔS) and molecular docking results suggested that the binding of Cpu to pepsin/trypsin were driven by hydrogen bonds and van der Waals forces. Based on Förster's theory, the binding distance (r) between pepsin/trypsin and Cpu was calculated to be 3.072/2.784 nm, which implies that non-radiative energy transfer occurs from enzyme to Cpu. Furthermore, absorption, CD, and FT-IR spectral analysis provided an evidence that the presence of Cpu induced notable changes in the secondary structures and microenvironmental of both pepsin and trypsin, supporting its significant influence on these enzymes. [ABSTRACT FROM AUTHOR]

Both physical ageing and annealing processes have a remarkable effect on mechanical properties of polymers. In the present work, the physical ageing and annealing processes of poly (N-vinyl carbazole) (PNVC), which encompasses phase separation on purification and thermal annealing, have been followed by differential scanning calorimetry (DSC) at different temperatures. The thermal responses were analysed by both generalized two-dimensional correlation mapping (2D-CM) and multiple-perturbation 2D correlation mapping. The asynchronous correlation cross-peak at (233, 211) °C was a measure of the phase separation of the two stereoforms that contributed to each process. Its intensity was a measure of the effect of holding time on the phase separation, and this was decreased with increasing the holding temperature, which indicated that the occurrence of phase separation was faster at higher holding temperature. The negative values of the correlation peaks indicated that the two relaxation processes changed on the opposite direction. A step change in the correlation intensity with a reflection temperature around 240 °C was observed. The later temperature is interestingly, consistent with the lower critical solution temperature of PNVC reported elsewhere. 2D-CM and its valuable tools provide new routines for DSC thermal responses analysis to extract useful information from complicated polymer systems. [ABSTRACT FROM AUTHOR]

We designed and synthesized new indolocarbazole-triazine derivatives, 9-di-tert-butyl-5,7-bis(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-5,7-dihydroindolo[2,3-b]carbazole (2TRZ-P-ICz) and 3,9-di-tert-butyl-5,7-bis(5′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′:3′,1″-terphenyl]-2′-yl)-5,7-dihydroindolo[2,3-b]carbazole (2TRZ-TP-ICz), as new bipolar host materials for red phosphorescent OLEDs. In the film state, 2TRZ-P-ICz and 2TRZ-TP-ICz exhibited photoluminescence maxima at 480 nm and 488 nm, respectively. The dipole moment characteristics of the new compounds under various solvent conditions were investigated using the Lippert–Mataga equation. The results showed that the dipole moment of 2TRZ-P-ICz is 26.9D, while that of 2TRZ-TP-ICz is 21.3D. The delayed fluorescence lifetimes were 0.188 μs for 2TRZ-P-ICz and 2.080 μs for 2TRZ-TP-ICz, with 2TRZ-TP-ICz showing TADF characteristics. Additionally, 2TRZ-TP-ICz was found to have a ΔEST of less than 0.2 eV. The triplet energy levels of the newly synthesized bipolar host materials were found to be 2.72 and 2.75 eV, confirming their suitability for use in red phosphorescent OLEDs. To investigate the carrier mobility of the synthesized materials, hole-only devices and electron-only devices were fabricated and tested. The hole mobility value at 1V was found to be 3.43 × 10−3 cm2/Vs for 2TRZ-P-ICz and 2.16 × 10−3 cm2/Vs for 2TRZ-TP-ICz. For electron mobility at 1V, 2TRZ-P-ICz showed a value of 4.41 × 10−9 cm2/Vs, while 2TRZ-TP-ICz exhibited a value of 9.13 × 10−9 cm2/Vs. As a result, when the new material was used as a host in red phosphorescent OLEDs, 2TRZ-TP-ICz achieved a current efficiency of 9.92 cd/A, an external quantum efficiency of 13.7%, CIE coordinates of (0.679, 0.319), and an electroluminescence maximum wavelength of 626 nm. [ABSTRACT FROM AUTHOR]

Various indoles and carbazoles were synthesized from o‐alkenyl anilines and o‐aryl anilines by the β‐C(sp2)−H bond amination cyclization without any oxidants or hydrogen acceptors. Likewise, employing o‐alkyl anilines as substrates, indole products are also obtained by the β‐C(sp3)−H bond amination cyclization, and dehydrogenation. In this cross‐dehydrogenative coupling, many different functional groups are tolerated, and hydrogen gas is the only by‐product, thereby providing an intrinsically waste‐free approach for the synthesis of indoles and carbazoles. [ABSTRACT FROM AUTHOR]

An efficient access to novel families of cyano‐containing polyheteroaromatic D−A molecules with extended π‐conjugation, including dibenzo[c,h][1,6]naphthyridine derivatives, has been elaborated. The synthetic strategy is based on the sequence of metal‐catalyzed annulation and cross‐coupling reactions starting from available 4‐ethynyl‐5,6‐difluoro‐7‐(p‐methoxyphenyl)‐2,1,3‐benzothiadiazole to get a new series of isoquinoline‐linked BTD‐based D−A compounds, which further undergo a selective cyanation to afford the corresponding mono‐CN‐ or di‐CN‐BTD derivatives depending on the reaction conditions. In course of the investigation of cyanation process, a new type of intramolecular heterocyclization included the transformation of the benzothiadiazole core into hardly accessible dibenzo[c,h][1,6]naphthyridine framework has been unexpectedly discovered. The protocols developed tolerate a wide range of donor blocks such as diphenylamine, carbazole, dibenzoazepine and dihydroacridine. [ABSTRACT FROM AUTHOR]

A Brønsted acid catalyzed direct and dual C−H amination of carbazoles and indolocarbazoles with N‐Ts iminoquinone acetal is reported. It is characterized that the mentioned C−H amination was determined by the selection of catalysts and the molar ratio of the starting materials. The efficiency of this protocol was showcased by diverse carbazolylamine and indolocarbazolylamine assemblies. The late‐stage functionalization of a series of natural products fully illustrates the synthetic value of this methodology. [ABSTRACT FROM AUTHOR]

Bio‐inspired by natural species and previous research works, nanotubes are prepared by soft‐template electropolymerization in micellar solution. Various thiophene‐based and carbazole‐based monomers are designed from a triphenylamine core. With one of the carbazole‐based monomers, which is fully conjugated and with a star‐like structure, gecko‐like surface structures are obtained even if the structure is not perfectly planar. Extremely long and densely packed‐microtubes are reached especially at constant potential. However, the surfaces are not both highly hydrophobic and with strong water adhesion, but are superhydrophilic. These wetting properties can be explained by a high surface energy (γSV)=41.9 mN m−1 compared to gecko foot even if the natural gecko feet are also chemically inhomogeneous, or by differences in the arrangement of the surface structures. [ABSTRACT FROM AUTHOR]

Objective/Background: Carbazole derivatives have a tricyclic skeleton, consisting of a central pyrrole ring fused with two benzene rings. Carbazole derivatives are an important class of nitrogen-containing heterocyclic compounds that are widely found in nature and in synthetic source. These heterocycles possess a wide range of bioactivities and some of them have been marketed as drugs for the treatment of various diseases. Although some review articles on carbazole alkaloids have appreared in the literature, they are quite outdated. The current study offers a comprehensive review on the isolation and bioactivities of carbazole alkaloids within a decade. The article might be useful for chemists who work in alkaloid chemistry as well as pharmaceutical area. Methods: ' Carbazole alkaloids' was the most useful keyword to search for literature data. References have been collected from various resources such as Google Scholar, SciFinder, and PubMed. More than 70 electronic publications were obtained from these resources. Results: More than 230 carbazole alkaloids have been isolated and structurally elucidated from different sources. Carbazole alkaloids possess a wide range of bioactivities, such as antimicrobial, antiimflamatory, anticancer, neuroprotective properties activities. Conclusion: In this review article, we have summarized 66 studies on isolation and bioactivities of carbazole alkaloids in the literature. More than 230 carbazole alkaloid compounds have been isolated and identified. In addition, the article also gives an overview on bioactivities of carbazole alkaloids. [ABSTRACT FROM AUTHOR]

Elicitors have a substantial impact on the accumulation of phytochemical components in wild plants. The present study aimed to evaluate the impact of salicylic acid (SA) and methyl jasmonate (MJ) on the enrichment of carbazole alkaloids (CAs) in the leaves of Murraya koenigii under controlled environment. Effect of elicitors at 1.0, 1.5 and 2.0 mM and their time of exposition 6 h, 12 h, 24 h, 2 days and 5 days were evaluated. Methanolic extracts of the treated samples were subjected to UPLC-ESI-QTRAP LC-MS/MS analysis for the separation and subsequent quantification of seven identified CAs, viz. murrayamine A, koenigine, koenimbidine, koenimbine, mahanine, 8,8′-biskoenigine and mahanimbine. Accumulation of all the CAs was found to be enhanced with both the elicitors, but it was dependent on the type of elicitor, its concentration, and time of exposition. The data were analyzed through multivariate statistical models, like PCA, HCA and PLS-DA. The analysis revealed that 1.5 mM dose of MJ and SA had a significant influence on CAs accumulation at 24 and 12 h, respectively. Five marker CAs from both MJ and SA-treated samples were identified using VIP scoring. These findings suggest that MJ and SA with their specific concentration and exposition time could be used for the accumulation of particular CA to a substantial limit in this plant. [ABSTRACT FROM AUTHOR]

A twisted five-ring fused compound, N-(2-decyltetradecyl)-7H-benzo[4,5]thieno[2,3-b]carbazole-S,S-dioxide (i-BTOCz), was synthesized and characterized. By introducing i-BTOCz into the main chains of polyfluorene (PF) and polycarbazole (PCz), respectively, blue light-emitting polymers (PF-i-BTOCzs/PCz-i-BTOCzs) were synthesized. Excellent thermal stability was achieved, along with a strong intramolecular charge transfer (ICT) effect of i-BTOCz and the resulting polymers. For the polymers, as the content of i-BTOCz increased, the lowest unoccupied molecular orbital (LUMO) energy levels decreased slightly and the highest occupied molecular orbital (HOMO) energy levels were almost unchanged. The photoluminescence (PL) spectra showed slight broadening in solution and basically no change in film, which due to the twisted molecular structure suppressed the decrease in the energy levels and redshift of spectra. With the current density in the range of 100–500 mA cm−2, the electroluminescence (EL) spectra of the polymers were almost unchanged, indicating outstanding EL stability. As the content of i-BTOCz increased, a slight redshift of the EL spectra was observed for the PF-i-BTOCzs and PCz-i-BTOCzs, with basically unchanged Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.14) and (0.17, 0.16), respectively. The maximum luminous efficiency (LEmax) of PF-i-BTOCz20 and PCz-i-BTOCz20 was 1.11 cd A−1 and 1.41 cd A−1, while the LEmax of PF and PCz was 0.58 cd A−1 and 0.35 cd A−1, respectively, indicating that introducing the twisted unit into the main chains of PF or PCz could be a viable strategy for restraining the redshift of spectra and obtaining efficient blue light-emitting polymers. [ABSTRACT FROM AUTHOR]

Inspired by circularly polarized luminescence (CPL), artificial CPL assembly has attracted intense attention. However, precise manipulation of chiral transfer from achiral and luminescent materials remains a formidable challenge. Two sandwiched carbazole and binaphthol derivatives composed of pyridine or trifluoride methyl benzene have been synthesized. Among R‐1 and R‐2, their spectra were found in the violet region, both in the solution and the film state. They exhibit the photoluminescence dissymmetry factors up to 1.4 × 10−3 for R‐2 and an opposite value of −5.6 × 10−4 for R‐1. Theoretical CPL and circular dichroism (CD) studies were in good agreement with the experimental data and deciphered their opposite signals by the transition electric and magnetic moment. Our study offers a strategy for studying the charge and chiral transfer. [ABSTRACT FROM AUTHOR]

Abstract Developing cost-effective, high-efficiency, and stable hole transporting materials (HTMs) is crucial for replacing traditional spiro-OMeTAD in perovskite solar cells (PSCs) and achieving sustainable solar energy solutions. This work presents two novel air-stable HTMs based on a spiro[fluorene-9,9′-xanthene] (SFX) core functionalized with N-methylcarbazole (XC2-M) and N-hexylcarbazole (XC2-H) rings. These HTMs were synthesized via a straightforward, three-step process with good overall yields (∼40%) and low production costs. To further reduce device cost, carbon back electrodes were employed. The resulting PSCs, with a structure of FTO/SnO2/Cs0.05FA0.73MA0.22Pb(I0.77Br0.23)3/HTM/C achieved power conversion efficiencies (PCEs) of 13.5% (XC2-M) and 10.2% (XC2-H), comparable to the reference spiro-OMeTAD device (12.2%). The choice of alkyl chain on the HTM significantly impacts film morphology and device stability. The XC2-H device exhibited exceptional long-term stability, retaining approximately 90% of its initial PCE after 720 h of storage in 30–40% humidity air without encapsulation. This surpasses the performance of both the spiro-OMeTAD (55% retention) and XC2-M (68% retention) devices. The superior stability of XC2-H is attributed to its highly hydrophobic nature and the formation of a compact, smooth film due to interdigitation of the hexyl chains. The straightforward synthesis of XC2-H from commercially available materials offers a promising approach for large-scale PSC production.

Abstract Background Carbazoles are an important class of heterocyclic aromatic compounds that contain nitrogen atom in the ring. They have a large-conjugated system, attractive “electrical and charge-transport properties”, and the ability to efficiently incorporate different functional groups into the structurally inflexible carbazolyl ring. Main text Carbazole derivative ECCA acts as an anticancer agent by reactivating the P53 molecular signaling pathway; similarly, some other derivatives of carbazole show antifungal activity by acting on the RAS-MAPK pathway. Carbazole derivatives also show their effect on inflammation by inhibiting the p38 mitogen-activated protein kinase signaling pathway by stopping the conversion of DAXX protein into ASK-1. By modifying the AKT molecular signaling pathway through boosting protein phosphatase activity in the brain, they show anti-Alzheimer’s activity and also by translocating the GLUT4 these are effective against diabetes. Conclusion After exploring the literature on carbazole, it was found that carbazole has an immeasurably great potential for the treatment of various diseases as the carbazole nucleus leads to various synthesized derivatives which are used for their pharmacological activities. So there is a need to explore carbazole for some newer drugs.

Constructing folded molecular structures is emerging as a promising strategy to develop efficient thermally activated delayed fluorescence (TADF) materials. Most folded TADF materials have V‐shaped configurations formed by donors and acceptors linked on carbazole or fluorene bridges. In this work, a facile molecular design strategy is proposed for exploring sandwich‐structured molecules, and a series of novel and robust TADF materials with regular U‐shaped sandwich conformations are constructed by using 11,12‐dihydroindolo[2,3‐a]carbazole as bridge, xanthone as acceptor, and dibenzothiophene, dibenzofuran, 9‐phenylcarbazole and indolo[3,2,1‐JK]carbazole as donors. They hold outstanding thermal stability with ultrahigh decomposition temperatures (556–563 °C), and exhibit fast delayed fluorescence and excellent photoluminescence quantum efficiencies (86 %–97 %). The regular and close stacking of acceptor and donors results in rigidified molecular structures with efficient through‐space interaction, which are conducive to suppressing intramolecular motion and reducing reorganized excited‐state energy. The organic light‐emitting diodes (OLEDs) using them as emitters exhibit excellent electroluminescence performances, with maximum external quantum efficiencies of up to 30.6 %, which is a leading value for the OLEDs based on folded TADF emitters. These results demonstrate the proposed strategy of employing 11,12‐dihydroindolo[2,3‐a]carbazole as bridge for planar donors and acceptors to construct efficient folded TADF materials is applicable. [ABSTRACT FROM AUTHOR]

Carbazole‐derived self‐assembled monolayers (SAMs) with excellent hole‐extraction and injection properties are promising hole‐transporting materials for perovskite optoelectronic devices, including perovskite solar cells (PSCs) and perovskite light‐emitting diodes (PeLEDs). The performance and thermal stability of these SAMs are heavily influenced by their chemical structure. Herein, the construction of fused carbazole‐based SAMs is proposed by expanding the π‐conjugation of the carbazole unit for application in PSCs and PeLEDs. Three proof‐of‐concept SAMs are designed and synthesized, termed XS8, XS9, and XS10, that feature highly rigid and planar fused carbazole as the donor and a conjugated alkene unit as the linker. This conjugated extension improves planarity, stability, and enhances the molecular dipole moment. Among these, XS10, with the highest degree of conjugation, demonstrated superior performance in perovskite‐based devices. The PSC device utilizing XS10 achieves a maximum power conversion efficiency (PCE) of 20.28%, surpassing the 17.19% PCE of the classic 2PACz‐based device. Similarly, the PeLED device with XS10 achieves a maximum external quantum efficiency (EQE) of 16.6%, compared to 14.5% for PEDOT‐based devices. This work provides a novel molecular design strategy for creating efficient and stable SAMs for perovskite optoelectronics and other organic electronic devices. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Photoinitiators of the oxime ester (OXE) or ketoxime ester (OXE‐CO) type can rapidly undergo N—O bond cleavage and generate free radicals to initiate photopolymerization under LED excitation, occupying an important position in the field of photocuring. However, the commercial OXEs, e.g., OXE 01 and 02 with λmax's at 326 and 344 nm, respectively, still do not well match the emission spectra of LEDs. Developing novel OXEs/OXE‐COs with high photosensitivity for long‐wavelength LEDs has great significance. Here, four new OXEs/OXE‐COs with nitro‐carbazole‐styrene conjugated chromophore were designed, synthesized, and used as photoinitiators. Results demonstrated that all photoinitiators had strong absorption within the UV–vis range (λmax: 381—392 nm, εmax: 8200—11500 M−1·cm−1). Molecular design of the oxime ester cleavage to produce a small volume methyl group and a methacryl group with an unsaturated double bond brings high activity and low migration, respectively, in one‐photon polymerization under 365—450 nm LEDs excitation. Moreover, OXEs/OXE‐COs with PETA exhibited a wide processing window, high resolution (line accuracy~100 nm) and good nano‐patterning capability under 780 nm femtosecond laser irradiation in two‐photon polymerization, indicating their great potential in 2D/3D microfabrication technologies. [ABSTRACT FROM AUTHOR]

Efficient blue multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials are highly desired for the fabrication of organic light‐emitting diodes (OLEDs) with high color purity. But only very limited carbonyl‐nitrogen (CO‐N) blue MR‐TADF are well‐developed. Herein, two new blue CO‐N MR‐TADF molecules (tBuPQCZ and 2tBuPQCZ) are explored by introducing bulky substituents to a planar CO‐N MR‐TADF core constructed by fusing carbonyl groups with carbazole, and their thermal stability, electronic structures, and photophysical properties are investigated. They exhibit blue photoluminescence (PL) peaks at 451 and 447 nm, and narrow full width at half maximums (FWHMs) of 26 and 25 nm in toluene. In doped films, they exhibit strong blue emissions with PL peaks at 474 and 469 nm, FWHMs of 51 and 49 nm, and satisfactory PL quantum yields of 80% and 72%. Moreover, blue OLEDs using them as emitters exhibit excellent external quantum efficiencies (EQEs) of 20.4% and 21.5%, and the hyperfluorescence OLEDs based on them provide state‐of‐the‐art EQEs of 30.1% and 29.0% with small FWHMs of 34 and 32 nm and Commission Internationale de I'Eclairage coordinates of (0.136, 0.134) and (0.141, 0.105). The insights gained in this work should be valuble for the development of efficient blue CO‐N MR‐TADF materials. [ABSTRACT FROM AUTHOR]

In the past, considerable effort are focused on advancing blue organic light‐emitting diodes (OLEDs) based on 1,3‐bis(N‐carbazolyl)benzene (mCP). To enhance and stabilize the device performance in vacuum‐processed OLEDs, it is essential to optimize the thermally stable organic materials constituting the emitting layer. The proposed novel carbazole derivative, Ad‐mCP, is designed and synthesized as a host material for blue thermally activated delayed fluorescence OLEDs, which are ideal for vacuum processing. Ad‐mCP exhibits a high glass transition temperature and triplet energy (T1), making it highly compatible with the blue dopant 2,11,14‐tri‐tert‐butyl‐N,N,5‐tris(4‐(tert‐butyl)phenyl)−5H‐5,8b‐diaza‐15b‐borabenzo[a]naphtho[1,2,3‐hi]aceanthrylen‐7‐amine emitter. The incorporation of a rigid adamantane unit into the carbazole group modifies the molecular structure of mCP, preserving crucial photophysical properties, such as T1,while enhancing the morphological and thermal stability of the host material in its film state. Moreover, the spatially hindered molecular structure of Ad‐mCP improves the photoluminescent quantum yield of the emissive layer and enhances charge balance, crucially contributing to the overall efficiency of the OLEDs. As a result, the exceptional performance of Ad‐mCP as a host material for OLEDs resulted in a remarkably high maximum external quantum efficiency of 29.9%, demonstrating superior stability in efficiency even after thermal annealing compared to mCP devices. [ABSTRACT FROM AUTHOR]