Anthracene Derivatives Research Articles

Non-doped OLEDs based on anthracene derivatives with aggregation-induced emission and piezochromism properties

The utilization of anthracene as the core to construct conjugated organic materials typically allows for the display of a range of optical and electroluminescent properties. In this study, two anthracene derivatives containing triphenylamine/diphenylamine and 4,6-diphenyl-1,3,5-triazine moieties 4-(10-(4,6-diphenyl-1,3,5-triazin-2-yl)anthracen-9-yl)-N,N-diphenylaniline (TPAAnTrz) and 10-(4,6-diphenyl-1,3,5-triazin-2-yl)-N,N-diphenylanthracen-9-amine (DPAAnTrz) have been synthesized and investigated systematically. It was found that these two obtained compounds exhibit a noticeable aggregation-induced emission (AIE) effect and reversible piezofluorochromic (PFC) behavior. In comparison to DPAAnTrz, TPAAnTrz demonstrates relatively weak intermolecular interactions and a distorted molecular structure, leading to more prominent piezofluorochromic behavior. TPAAnTrz exhibited weaker intermolecular interactions and a distorted molecular structure compared to DPAAnTrz, leading to more pronounced piezofluorochromic behavior. By utilizing TPAAnTrz and DPAAnTrz as emitters, the non-doped devices can exhibit maximum efficiencies of 13.2 and 10.1 cd/A, respectively, with negligible efficiency roll-off, even at high brightness levels. This demonstrates a significant potential for optoelectronic devices with high performance.

Isolation, identification and quantification anthracene derivatives in the underground organs of Rumex crispus

Isolation, identification and quantification anthracene derivatives in the underground organs of Rumex crispus

Designing of new functionalized imidazolium based ionic liquids attached to the antracene derivatives and investigation on the influence of intramolecular hydrogen bondings in anions on their intermolecular hydrogen bondings and some of the other properties: A DFT M06-2X-GD3 study

To promote the development of new functionalized ionic liquids, it is necessary to get a deeper insight into their features of physicochemical and electronic and molecular structure. In this study, the interaction energies and structural and vibrational frequencies parameters in accompanied with some of the physiochemical, electronic and optic attributes of ionic liquids designed by the covalently attachement of imidazolium to anthracene derivatives ([X-AnMIM][A2] and [X-AnMIM][A3], X: NH2, OH, OMe, H, Cl, CHO, CN and NO2) ILs have been evaluated. Two conjugate bases of acids 1,3,5-pentanetriol (A2) and 3-(2-hydroxyethyl)-1,3,5-pentanetriol (A3) are used as anions which have two and three intramolecular hydrogen bonds, respectively. Based on the results of calculations at M06-2X-GD3/6-311++(d,p) level of theory, the differences in these properties in addition to the structural type of anions and cations can be attributed to the cation- anion , intra and intermolecular hydrogen bonding, interactions in ionic liquids. The results depict that the ILs based on A2 anions form stronger hydrogen bonds with [X-AnMIM]+ cations. The potency of interaction between cations and anion reduces with the increasement in the number of intramolecular hydrogen bonds and also decreasement in the basic strength in the anionic part. A clear red shift is observed between [X-AnMIM][A2] and [X-AnMIM][A3] ILs and isolated anthracene, which is a clear manifestation of the effect of the imidazolium cation on the electronic energy levels of anthracene. It can be expected that the studied ILs are not electrochemically stable during the electrochemistry applications.

Synthesis and Characterization of New Compounds by Enzymatically Catalysed Diels-Alder Reactions

The Diels-Alder (DA) reaction is one of the important chemical transformations to create the C–C bonds with predicted regio- and stereo-selectivity, which lead to the forming of bulk organic molecules. Despite of the significant efforts in this filed, the control of the stereoselectivity of DA reactions remain so difficult. Despite the significant efforts in this field, controlling of stereoselectivity of DA reactions remains so difficult. The design of the enzymatic DA reactions provides scientists with a huge advantage in increasing the selectivity of DA reaction products. This work aims to apply the friendly environmental method includes the application of the current approach in enzymatic DA reactions by formation the new organic compounds through the enzymatic DA reactions between anthracene derivatives as dines and pyrrole derivatives as dienophiles. All DA reactions were curried out in the inert environment using the nitrogen gas. The prepared compounds were caramelized using various techniques including mass spectroscopy, nuclear magnetic resonance, and Fourier transform infrared. The results showed that all products of DA reactions containing unnatural dienes with endo-configuration, in addition to obtain 53%–94% isolated yields. Consequently, this study provides an efficient method to control the stereochemistry of DA reactions.

Self-Assembled Triangular Prismatic Cages with Kinetic Inertness.

Two triangular prismatic cages were synthesized by combining a trishydrazide and two bisformyl precursors in strongly acidic water, where the dynamic nature of hydrazone was turned ON. An anionic guest was used as the template to drive the cage formation. Performing counterion exchange removed both the template and the Brønsted acid. The removal of the latter afforded the cages' kinetic inertness by turning OFF the reversibility of hydrazone. The cages can thus be used for recognizing various guests in water without observable degradation, driven by the hydrophobic effect. Upon being accommodated within the cage cavities, an anthracene derivative was protected from UV-stimulated oxidation, which would occur otherwise in the bulk solution without the protection from the host.

Supramolecular scaffold-directed two-dimensional assembly of pentacene into a configuration to facilitate singlet fission.

Molecular assemblies featuring two-dimensionality have attracted increasing attention, whereas such structures are difficult to construct simply relying on spontaneous molecular assembly. Here, we present two-dimensional assemblies of acene chromophores achieved using a tripodal triptycene supramolecular scaffold, which have been shown to exhibit a strong ability to assemble molecular and polymer motifs two-dimensionally. We designed pentacene and anthracene derivatives sandwiched by two triptycene units. These compounds assemble into expected two-dimensional structures, with the pentacene chromophores having both sufficient overlap to cause singlet fission and space for conformational change to facilitate the dissociation of a triplet pair into free triplets, which is not the case for the anthracene analog. Detailed spectroscopic analysis revealed that the pentacene chromophore in the assembly undergoes singlet fission with a quantum yield of 88 ± 5%, giving rise to triplet pairs, from which free triplets are efficiently generated (ΦT = 130 ± 8.8%). This demonstrates the utility of the triptycene-based scaffold to design functional π-electronic molecular assemblies.

9,10-Bis[(4-(2-hydroxyethyl)piperazine-1-yl)prop2-yne-1-yl]anthracene: G-Quadruplex Selectivity and Anticancer Activity.

G-Quadruplexes (G4s) are appealing targets for anticancer therapy because of their location in the genome and their role in regulating physiological and pathological processes. In this article, we report the characterization of the molecular interaction and selectivity of OAF89, a 9,10-disubstituted G4-binding anthracene derivative, with different DNA sequences. Advanced analytical methods, including mass spectrometry and nuclear magnetic resonance, were used to conduct the investigation, together with the use of in silico docking and molecular dynamics. Eventually, the compound was tested in vitro to assess its bioactivity against lung cancer cell lines.

Distance-Independent Efficiency of Triplet Energy Transfer from π-Conjugated Organic Ligands to Lanthanide-Doped Nanoparticles.

Lanthanide-doped nanoparticles (LnNPs) possess unique optical properties and are employed in various optoelectronic and bioimaging applications. One fundamental limitation of LnNPs is their low absorption cross-section. This hurdle can be overcome through surface modification with organic chromophores with large absorption cross-sections. Controlling energy transfer from organic molecules to LnNPs is crucial for creating optically bright systems, yet the mechanisms are not well understood. Using pump-probe spectroscopy, we follow singlet energy transfer (SET) and triplet energy transfer (TET) in systems comprising different length 9,10-bis(phenylethynyl)anthracene (BPEA) derivatives coordinated onto ytterbium and neodymium-doped nanoparticles. Photoexcitation of the ligands forms singlet excitons, some of which convert to triplet excitons via intersystem crossing when coordinated to the LnNPs. The triplet generation rate and yield are strongly distance-dependent. Following their generation, TET occurs from the ligands to the LnNPs, exhibiting an exponential distance dependence, independent of solvent polarity, suggesting a concerted Dexter-type process with a damping coefficient of 0.60 Å-1. Nevertheless, TET occurs with near-unity efficiency for all BPEA derivatives due to the lack of other triplet deactivation pathways and long intrinsic triplet lifetimes. Thus, we find that close coupling is primarily important to ensure efficient triplet generation rather than efficient TET. Although SET is faster, we find its efficiency to be lower and more strongly distance-dependent than the TET efficiency. Our results present the first direct distance-dependent energy transfer measurements in LnNP@organic nanohybrids and establish the advantage of using the triplet manifold to achieve the most efficient energy transfer and best sensitization of LnNPs with π-conjugated ligands.

Electron Transport through Linear-, Broken-, and Cross-Conjugated Polycyclic Compounds.

Quantum interference (QI) effects offer unique opportunities to modulate charge transport through single molecules. In recent years, several transmission selection rules have been developed to determine constructive and destructive QIs in an intuitive and simple manner, although some of these rules fail for cross-conjugated systems. In this work, we evaluate the performance of distinct transmission rules on a broad series of anthracene and fluorene derivatives with distinctive structural features including linear-, broken-, and cross-conjugation, heteroatoms, and five-membered rings as such species affords a predictive challenge for the qualitative selection rules for QI effects. The electron transport properties and local transmission plots are first evaluated by combining DFT and the nonequilibrium Green function method allowing for an equal-footing comparison of the conductance of the different polycyclic compounds. Our findings are in line with experimental observations on the influence of the type of conjugation and the connectivity to the metallic electrodes on the transport properties. Thus, cross-conjugated systems exhibit reduced conductance values as compared to the linear-conjugated ones, although the transmission is enhanced in the meta-connected junctions. Remarkably, our study reveals that aromatic cores exhibit generally larger zero-bias conductance for a given connectivity, in contrast to the negative aromaticity-conductance relationship found in literature.

Anthracene derivatives with electron-transport units for non-doped blue fluorescent organic light-emitting diodes

Blue organic light-emitting diodes with non-doped emissive layer (EML) structures have been garnered increasing interest due to their convenience of manufacturing process. For this purpose, we designed and synthesized two novel anthracene derivatives, PO2PhAnTz and PO2PhAnBI. Both derivatives exhibited bright blue electroluminescence emission and a relatively low operating voltage with a simple bilayer device structure. The PO2PhAnBI with triphenyl-phosphine oxide moiety as host, anthracene core as dopant and benzimidazole as electron transport group, realized a balanced bipolar transport and attained a maximum external quantum efficiency of 5.74 %. The findings shed light on the molecule design role toward high-efficiency non-doped blue OLEDs.

Cobalt(II)‐Nitromethane Complex as an Efficient Catalyst Of Demanding Diels‐Alder Reactions on the Example of an Anthracene‐Chalcone System

AbstractDiels‐Alder (DA) cycloaddition of chalcones to anthracene and its 9‐substituted derivatives is an example of a demanding reaction that is not effective even under increased pressure. In this article we show that an easily accessible complex cation [Co(CH3NO2)6]2+ stabilized by weakly coordinating anion [Al(OC(CF3)3)4]− exhibits good catalytic activity in the reaction. Our screening covering chalcone and anthracene derivatives with either activating or deactivating effects on reactivity in DA cycloadditions show that the catalyst allows to obtain [4+2] cycloadducts with yields up to 99 % under mild conditions, even for 9‐bromoanthracene – a very poor diene in DA reactions. The reaction proceeds best in liquid SO2, which is an unusual solvent for this type of reaction. 9‐methylanthracene ‐ the most reactive diene among those tested in the study ‐ gives two regioisomeric cycloadducts and their ratio depends on the solvent used. Modeling of the reaction with DFT methods shows that Co(II) significantly lowers the activation energy of the cycloaddition. In the case of 9‐bromoanthracene the effect is much more pronounced than with e. g. recently reported redox‐activation of the diene, which is in agreement with much better yields obtained with the use of the cobalt catalyst.

Enhancement of Blue Doping-Free and Hyperfluorescent Organic Light Emitting Diode Performance through Triplet–Triplet Annihilation in the Derivatives of Anthracene and Carbazole

Enhancement of Blue Doping-Free and Hyperfluorescent Organic Light Emitting Diode Performance through Triplet–Triplet Annihilation in the Derivatives of Anthracene and Carbazole

Water-dispersable photoreactors based on core–shell mesoporous silica particles

Robust solid-core silica particles with submicrometer size and anthracene-containing mesoporous shell were obtained and studied as model water-dispersable photoreactors. An anthracene derivative containing a triethoxysilyl group was synthesized and co-condensed with tetraethoxysilane in various ratios to form a photoactive mesoporous shell with a thickness up to approximately 80 nm on previously prepared solid silica particles. Mesopores of as-synthesized particles, without a commonly applied removal of the micellar templates, offered a confined space for solubilization of hydrophobic molecules. Efficient excitation energy transfer from anthracene chromophores to both hydrophobic (perylene) and hydrophilic (fluoresceine) encapsulated acceptors was observed in an aqueous dispersion of the particles. Photosensitized oxidation of encapsulated perylene was shown to proceed efficiently in such systems serving as water-dispersable photoreactors. Importantly, the designed core–shell systems were found to be stable for a long time (at least 24 months) and robust enough, thanks to the presence of solid cores, to be handled by centrifugation in aqueous dispersions. All these features make them promising candidates for reusable systems for the photosensitized degradation of water pollutants, especially hydrophobic pollutants.

Enhancing Fast RISC in Hot‐Exciton Thermally Activated Delayed Fluorescence Emitter Through Fused Ring Modification: A Theoretical Insights

AbstractRecent progress has shown promising advancements in enhancing the Reverse intersystem crossing (RISC) process between high‐energy triplet states (Tn, n ≥ 1) and radiative singlet states (Sm) through the utilization of the classic D‐A‐D' strategy. In this study, 12 molecules employing phenyl carbazole and a peripheral phenanthroimidazole as the donors and fused cores as acceptors are theoretically designed. Additionally, electron‐withdrawing groups such as fluorine and cyano, as well as electron‐donating group like methoxy, are incorporated into anthracene, napthaoxadiazole, and napthothiadiazole derivatives, acting as fused core components. Theoretical analyses reveal that among the molecules examined, eight adhere to the three golden principle rules, demonstrating a large energy gap between S1‐T1, the minimal ΔES1‐T2, and large T2‐T1. Additionally, these molecules exhibit significant Spin‐orbit coupling (SOC) and maintain a strong Hybridized local and charge transfer (HLCT) character, facilitating the fast hRISC from T2 to S1. The auxiliary inclusion of heteroatoms, such as oxygen and sulfur, on the anthracene core, aligns with the prerequisite strategy, ultimately reinforcing the SOC. Furthermore, replacing the methoxy group on the Nz bridge significantly enhances the SOC, resulting in a substantial increase in the hRISC rate (10 +08 s−1). Overall, the findings substantially elevate the photophysical attributes of the designed molecules through the utilization of the hRISC channel.

Assessment of the content of biologically active substances in Hypericum perforatum along an altitude gradient

An assessment of the content of flavonoids in the herb St. John’s wort, selected in natural phytocoenosis along an altitudinal gradient, is presented. We used generally accepted methods described in the relevant manuals when conducting research. The material for the study was air-dried samples of the aerial parts of St. John’s wort (Hypericum perforatum) collected at different altitudes. The features of the accumulation of flavonoids (leucoanthocyanins, catechins, flavonols) and the amount of anthracene derivatives in the herb St. John’s wort (Hypericum perforatum) in the phase of mass flowering along an altitudinal gradient were studied. It has been shown that an increased level of anthracene derivatives (in terms of hypericin) is observed at altitudes of 615 - 716 m above sea level. The amount of anthracene derivatives (in terms of hypericin) significantly decreases along the altitudinal gradient. The content of catechins in samples taken along the altitudinal gradient varies within 0.17 - 0.36 mg%. It has been established that plants selected at different altitudes from 615 to 2025 m above sea level are characterized by other content of flavonoids. The samples in the altitude range 615 - 716 m above sea level have the maximum content. The plants selected in the vicinity of the village had the best characteristics for the accumulation of the mass fraction of flavonols. Makhchesk, Irafsky district of the Republic of North Ossetia - Alania, in coenopopulations of a cereal-forb meadow at 1340 m above sea level. Thickets of Hypericum perforatum are found on slopes of southern and southeastern exposure.

Phytochemical screening, investigation of the antisalmonella, antishigella, and antioxidant properties of the leaves of Rauvolfia vomitoria Afzel.

Rauvolfia vomitoria is a plant acclimatized in Benin - Africa that people use to treat several illnesses such as malaria, cough, typhoid fever, madness, toothache, diabetes, and nausea. The most used organs are leaves, stems, and roots. Thus, the purpose of this work is to contribute to the valorization of R. vomitoria by chemical and biological studies of this plant. Phytochemical analyses of the powder extracts were performed and revealed the presence of alkaloids, tannins, flavonoids, anthocyanins, saponins, terpenes, coumarins, mucilages, reducing compounds, free anthracene derivatives, bound anthracene derivatives (O-glycosides and C-glycosides) with absence of leuco-anthocyanins, quinone derivatives, steroids and cardiotonic glycosids. Evaluation of antisalmonella and antishigella properties of ethanol-water (70:30; V/V) and ethanolic extracts of R. vomitoria leaves showed minimum inhibitory concentrations (MIC) greater than 2000 µg.mL-1 against Salmonella and Shigella strains. The ethanolic extract was the most active by ABTS and FRAP methods and had very good antioxidant activity at scavenging concentration (SC50) equal to 138,62 µg.mL-1 and 185,99 µg.mL-1 respectively

Zirconium-based metal-organic framework with bis(hydroxyphenyl)anthracene derivative: molecular design, synthesis, crystal structures, and methane adsorption

Abstract A metal-organic framework (MOF) composed of a zirconium cluster with a bis(hydroxyphenyl)anthracene linker, Zr6O4(OH)4(adhb)6 (adhb: 4,4′-(anthracene-9,10-diyl)bis(2-hydroxybenzoic acid), was designed to achieve methane storage up to 300 g and batch synthesized without using an autoclave. This MOF can adsorb 65.4 cm3STP/cm3 and 4.7w% of methane at 294 K and 9.8 bar due to its large specific surface area of 1,818 m2/g and void fraction of 0.78 cm3/g. Furthermore, an octahedral cage model indicated that the anthracene ring provides a suitable pore entrance and steric hindrance for methane inclusion.

Phase Diagrams of Anthracene Derivatives in Pyridinium Ionic Liquids.

Crystal engineering for single crystallization of π-conjugated molecules has attracted much attention because of their electronic, photonic, and mechanical properties. However, reproducibility is a problem in conventional printing techniques because control of solvent evaporation is difficult. We investigated the phase diagrams of two anthracene derivatives in synthesized ionic liquids for non-volatile crystal engineering to determine the critical points for nucleation and crystal growth. Anthracene and 9,10-dibromoanthracene were used as representative π-conjugated molecules that form crystal structures with different packing types. Ionic liquids with an alkylpyridinium cation and bis(fluorosulfonyl)amide were good solvents for the anthracene derivatives from ca. 0 °C to 200 °C. The solubilities (critical points for crystal growth) of the anthracene derivatives in the ionic liquids reached the 100 mM level, which is similar to those in organic solvents. Ionic liquids with phenyl and octyl groups tended to show high-temperature dependence (a high dissolution entropy) with 9,10-dibromoanthracene. The precipitation temperature (critical point for crystal nucleation) at each 9,10-dibromoanthracene concentration was lower than the dissolution temperature. The differences between the dissolution and precipitation temperatures (supersaturated region) in the ionic liquids were greater than those in an organic solvent.

Principal Singlet Fission Properties Of Twisted Acenes.

Acenes, especially tetracene derivatives, are used as singlet fission materials. The recent synthesis of Dodecaphenyl tetracene (showing end-to-end twist angles of 96-98 degrees) and twisted anthracene derivatives show that the synthesis of twisted linear oligoacenes is possible. Energy calculations and NICS-X-scan studies predict that twisted acenes may be better singlet fission materials compared to their planar analogues.

Light-Induced Increase of the Local Molecular Coverage on a Surface.

Light is a versatile tool to remotely activate molecules adsorbed on a surface, for example, to trigger their polymerization. Here, we explore the spatial distribution of light-induced chemical reactions on a Au(111) surface. Specifically, the covalent on-surface polymerization of an anthracene derivative in the submonolayer coverage range is studied. Using scanning tunneling microscopy and X-ray photoemission spectroscopy, we observe a substantial increase of the local molecular coverage with the sample illumination time at the center of the laser spot. We find that the interplay between thermally induced diffusion and the reduced mobility of reaction products steers the accumulation of material. Moreover, the debromination of the adsorbed species never progresses to completion within the experiment time, despite a long irradiation of many hours.