- Investigations of the heavy atom effect occurring in bianthryl and 10,10′-dibromobianthryl. Fluorescence, cyclovoltamperometric and actinometric studies
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A preliminary study of photophysical and photochemical properties of 9,9′-bianthryl (BA) and 10,10′-dibromo,9,9′-bianthryl (DBrBA) is presented. Dual fluorescence occurring in bianthryl (BA) has been investigated in solvents containing heavy atoms, such as chlorine, bromine and iodine. The presence of heavy atoms reduces strongly the fluorescence lifetimes and the fluorescence quantum yields of BA, the effect is strongest in ethyl iodide, i.e. in the solvent containing the heaviest atom, iodine. On the other hand, it has been found that introduction of two heavy atoms (bromine) into the bianthryl molecule modifies noticeably its fluorescence properties, which indicates existance of an internal heavy atom effect. Again, a reduction of the fluorescence lifetime and the fluorescence quantum yield, compared to the parent molecule, has been observed. On the basis of these observations the mechanism of 1CT ?3LE intersystem crossing has been discussed. In BA the rate determining process is a reversible spin inversion within the radical pair. In DBrBA where the spin flip is accelerated by the presence of heavy atoms (bromines) the spin-allowed electron transfer 3CT ?3LE becomes important in the overall intersystem crossing process. It has been found that DBrBA undergoes a photoreduction in the presence of aromatic donors, such as amines, leading finally to BA. Similar reaction seems to be observed in electrochemical measurement. The reduction of DBrBA originates from the primary electron transfer process either photoinduced or electrochemical leading to the free anion radicals of DBrBA.
- Mac, Marek,Danel, Andrzej,Kizior, Katarzyna,Nowak, Pawel,Karocki, Andrzej,Tokarczyk, Bogdan
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- Clay encapsulated Cu(OH)x promoted homocoupling of arylboronic acids: An efficient and eco-friendly protocol
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Cu(OH)x has been encapsulated over montmorillonite-KSF by simple ologomeric deposition strategy. The resulting catalyst has been employed for selective homocoupling of arylboronic acids under ambient conditions without requirement of any ligand or base. This catalyst is easy to recover and shows excellent reusability without losing its activity. Techniques like XRD, SEM, TPR, IR, BET surface area measurement and XPS were used to characterize the catalyst. The present method promises for the simple and clean homocoupling of arylboronic acids.
- Dar, Bashir Ahmad,Singh, Snehil,Pandey, Nalini,Singh,Sharma, Priti,Lazar, Anish,Sharma, Meena,Vishwakarma, Ram A.,Singh, Baldev
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- Photoinduced C-C reactions on insulators toward photolithography of graphene nanoarchitectures
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On-surface chemistry for atomically precise sp2 macromolecules requires top-down lithographic methods on insulating surfaces in order to pattern the long-range complex architectures needed by the semiconductor industry. Here, we fabricate sp2-carbon nanometer-thin films on insulators and under ultrahigh vacuum (UHV) conditions from photocoupled brominated precursors. We reveal that covalent coupling is initiated by C-Br bond cleavage through photon energies exceeding 4.4 eV, as monitored by laser desorption ionization (LDI) mass spectrometry (MS) and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) gives insight into the mechanisms of C-Br scission and C-C coupling processes. Further, unreacted material can be sublimed and the coupled sp2-carbon precursors can be graphitized by e-beam treatment at 500 °C, demonstrating promising applications in photolithography of graphene nanoarchitectures. Our results present UV-induced reactions on insulators for the formation of all sp 2-carbon architectures, thereby converging top-down lithography and bottom-up on-surface chemistry into technology.
- Palma, Carlos-Andres,Diller, Katharina,Berger, Reinhard,Welle, Alexander,Bj?rk, Jonas,Cabellos, Jose Luis,Mowbray, Duncan J.,Papageorgiou, Anthoula C.,Ivleva, Natalia P.,Matich, Sonja,Margapoti, Emanuela,Niessner, Reinhard,Menges, Bernhard,Reichert, Joachim,Feng, Xinliang,R?der, Hans Joachim,Klappenberger, Florian,Rubio, Angel,Müllen, Klaus,Barth, Johannes V.
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Read Online
- Diphenylanthracene Dimers for Triplet-Triplet Annihilation Photon Upconversion: Mechanistic Insights for Intramolecular Pathways and the Importance of Molecular Geometry
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Novel approaches to modify the spectral output of the sun have seen a surge in interest recently, with triplet-triplet annihilation driven photon upconversion (TTA-UC) gaining widespread recognition due to its ability to function under low-intensity, noncoherent light. Herein, four diphenylanthracene (DPA) dimers are investigated to explore how the structure of these dimers affects upconversion efficiency. Also, the mechanism responsible for intramolecular upconversion is elucidated. In particular, two models are compared using steady-state and time-resolved simulations of the TTA-UC emission intensities and kinetics. All dimers perform TTA-UC efficiently in the presence of the sensitizer platinum octaethylporphyrin. The meta-coupled dimer 1,3-DPA2 performs best yielding a 21.2% upconversion quantum yield (out of a 50% maximum), which is close to that of the reference monomer DPA (24.0%). Its superior performance compared to the other dimers is primarily ascribed to the longer triplet lifetime of this dimer (4.7 ms), thus reinforcing the importance of this parameter. Comparisons between simulations and experiments reveal that the double-sensitization mechanism is part of the mechanism of intramolecular upconversion and that this additional pathway could be of great significance under specific conditions. The results from this study can thus act as a guide not only in terms of annihilator design but also for the design of future solid-state systems where intramolecular exciton migration is anticipated to play a major role.
- Olesund, Axel,Gray, Victor,M?rtensson, Jerker,Albinsson, Bo
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supporting information
p. 5745 - 5754
(2021/05/06)
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- Co-crystals of 9,9′-bianthracene-10,10′-dicarboxylic acid with linear bidentate basic ligand molecules: Synthesis, crystal structure, and properties based on the layer structure exfoliated by water
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Co-crystals of 9,9′-dianthracene-10,10′-dicarboxylic acid (1) with the linear bidentate bases 9,9′-biacridine (bac), phenazine (phez), 4,4′-dipyridine (dpy), and DABCO (dabco) were synthesized. In the crystal structures of the co-crystals of 1 and bac, phez, and dpy, one-dimensional (1D) structures were formed through the hydrogen bonding between the acid and the base. For each combination of the acid and the bases, several kinds of polymorphic co-crystals with a similar structure were obtained. Among them, a combination of 1 and dabco gave three kinds of co-crystals which had a layered structure. In one of the co-crystals, a phenomenon where layers of the crystals could be exfoliated by dropping water was observed. The two-dimensional (2D) fingerprinting plot of the co-crystals showed that the major interaction to form the 1D structure was O-H?N hydrogen bonding and that to form the layered structure was the CH-π interaction, and the influence of the latter interaction on the robustness of the crystal was stronger than the former in the co-crystals.
- Azumaya, Isao,Hikawa, Hidemasa,Kikkawa, Shoko,Okayasu, Misaki
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p. 497 - 505
(2020/01/29)
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- Orthogonal Oriented Bisanthrancene-Bridged Bis(Triarylamine) Diradical Dications: Isolation, Characterizations and Crystal Structures
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Two bis(triarylamine) diradical dication salts 12+2[Al(ORF)4]? and 22+2[Al(ORF)4]? bridged with an orthogonal oriented bisanthrancene motif were synthesized. Their solid state and electronic structures were investigated by various experimental approaches in conjunction with theoretical calculations. Superconducting quantum interference device measurements and density functional theory calculations reveal that both of 12+ and 22+ feature open-shell singlet ground states with rather small singlet-triplet energy gaps; thus, they can be regarded as nearly pure diradicals (biradicals). Their diradical characters are enhanced by the orthogonal configuration of the bisanthrancene moiety which demonstrates the importance of the geometry of bridging units in turning the electronic structures of bis(triarylamine) dications.
- Wang, Lei,Zhang, Li,Fang, Yong,Zhao, Yue,Tan, Gengwen,Wang, Xinping
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supporting information
p. 1708 - 1711
(2019/05/22)
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- A new thiosemicarbazone fluorescent probe based on 9,9′-bianthracene for Hg2+ and Ag+
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A new 9,9′-bianthracene-based thiosemicarbazone (D1) has been successfully synthesized and utilized for chemosensors. The properties of D1 were systematically investigated by UV–Vis, fluorescence titration and theoretical calculations. As a result, D1 exhibits a characteristic fluorescence quenching phenomenon in the presence of Hg2+ or Ag+ compared to other metal cations (Na+, K+, Mg2+, Ba2+, Al3+, Zn2+, Fe2+, Pb2+, Cu2+, Co2+, Cd2+, Ni2+ and Mn2+). The detection limits of Hg2+ and Ag+ reach 6.62 × 10?7 M and 1.99 × 10?5 M, respectively. This is mainly attributed to the Hg2+ (or Ag+) forms a stable five-membered ring with the N atom in Schiff base C[dbnd]N and the S atom in thiourea. The results suggest that the probe D1 is a promising candidate for chemosensors in aqueous media due to its highly selectivity for Hg2+ and Ag+.
- Chen, Zhen-E,Zhang, Hai,Iqbal, Zafar
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- Dianthranide-based compounds as well as preparation method and application thereof as high-pressure transducer
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The invention relates to dianthranide-based compounds as well as a preparation method and an application thereof as a high-pressure transducer. The compounds have molecular inner conformation continuously changing under pressure, have a broad pressure sensing range and can be used for pressure detection in different environments. The detection results of the compounds can be recognized in two modes including a spectral recognition mode and a chromatic recognition mode, and the dianthranide-based compounds can be used for detection by a spectrometer and by naked eyes.
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Paragraph 0061-0065
(2018/03/24)
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- Highly efficient dual anthracene core derivatives through optimizing side groups for blue emission
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TP-AA-TPB, TP-AA-TPB, TPB-AA-TPB, TP-AA-DPA, TP-AA-TPA, and TPB-AA-TPA were synthesized using a 9,9'-bianthracene (AA core). Through a systematic side group change, we optimized the dual-core chromophore system and investigated the relationship between the core and the side groups. The ultraviolet-visible (UV-Vis) absorption of the six materials showed an intrinsic absorption peaks of anthracene in the range of 360 nm–410 nm and photoluminescence (PL) emission in the blue region. The minimum decomposition temperatures (Td) was 425 °C, the minimum melting temperatures (Tm) was 335 °C, and the minimum glass transition temperatures (Tg) was 176 °C. We achieved excellent overall electroluminescence (EL) efficiency in non-doped OLED devices using the six synthesized materials as emitting layer (EML). TPB-AA-TPA synthesized through size and polarity optimization of the side groups on the AA core had a current efficiency of 8.97 cd/A, power efficiency of 4.43 lm/W, external quantum efficiency (EQE) of 6.37%, and Commission Internationale de L'Eclairage coordinates (CIE) of (0.14, 0.19). TPB-AA-TPA also maintained blue emission and realized the highest EL efficiency among the six synthesized materials.
- Lee, Hayoon,Jo, Minjin,Yang, Garam,Jung, Hyocheol,Kang, Seokwoo,Park, Jongwook
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- The anthracene derivatives, organic EL material and its manufacturing method (by machine translation)
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PROBLEM TO BE SOLVED: To provide an anthracene derivative in which a specific solubility radical is introduced into an anthracene skeleton, thereby improving solubility, and that is suitable to be used for film production in a solution process, and further to provide an anthracene derivative in which a specific solution radical of the anthracene derivative is desorbed by an external stimulation, and that is as an organic EL material excellent in characteristics.SOLUTION: For instance, anthracene derivatives (HTL1) and (HTL2) are exemplified to be synthesized by reaction formula (A). The anthracene derivative excellent in organic EL characteristics is obtained by the desorption of an ester group by an external stimulation.
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Paragraph 0164-0165
(2017/07/14)
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- Reversible mechanochromic luminescence of phenothiazine-based 10,10′-bianthracene derivatives with different lengths of alkyl chains
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A series of 10,10′-bis(2-(N-alkylphenothiazine-3-yl)vinyl)-9,9′-bianthracene compounds (PVBAn, n = 2, 8, 12 and 16) with different lengths of N-alkyl chains have been designed and synthesized to systematically investigate the effect of chain length on their solid-state fluorescence properties. The results showed that these compounds emitted strong fluorescence in solution and in the solid state. Their emission wavelengths were also strongly affected by solvent polarity, indicating intramolecular charge transfer (ICT) transitions. Interestingly, the fluorescence emission and grinding-induced spectral shifts of PVBAn solids are alkyl length-dependent. PVBA2 shows the smallest fluorescence and absorption spectrum shifts under mechanical force stimuli. Homologues with longer alkyl chains exhibit similar mechanochromic behaviors and larger fluorescence contrasts after grinding. Moreover, the fluorescence emission of ground solid PVBA16 can recover at room temperature, but other compounds need high temperatures for fluorescence to be restored. Differential scanning calorimetry experiments reveal that the cold-crystallization temperature difference is responsible for thermal restoration behaviors. This work demonstrates the feasibility of tuning the solid-state optical properties of fluorescent organic compounds by combining the simple alteration of chemical structure and the physical change of aggregate morphology under external stimuli.
- Xue, Pengchong,Yao, Boqi,Liu, Xuhui,Sun, Jiabao,Gong, Peng,Zhang, Zhenqi,Qian, Chong,Zhang, Yuan,Lu, Ran
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p. 1018 - 1025
(2015/02/05)
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- Photoluminescence, redox properties, and electrogenerated chemiluminescence of twisted 9,9′-bianthryls
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To study the dual emission (from locally excited and charge transfer states) of sterically crowded 9,9′-bianthryl (BAHO) and its 10,10′-disubstituted derivatives, namely, 10,10′-dibromo-9,9′- bianthryl (BABR), 10,10′-bis(p-tolylethynyl)-9,9′-bianthryl (BAET), and 10,10′-bis(N,N-diphenyl-4-anilino)-9,9′-bianthryl (BATA) in detail, we probed their photophysical, redox, and electrogenerated chemiluminescence (ECL) responses. Dual emission for all of the molecules was noticed in PL, whereas in ECL only charge transfer emission was observed over a variety of experimental conditions. The PL in nonpolar solvents is significantly influenced by added supporting electrolyte, yielding exclusively charge transfer emission as in ECL. The stability of ECL proved to depend largely on the nature of the substituent, with triarylamine and bromo groups imparting constant ECL intensity over more than 60 cycles.
- Natarajan, Palani,Schmittel, Michael
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p. 10383 - 10394
(2013/11/06)
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- Highly efficient deep-blue organic electroluminescent devices (CIE y ≈ 0.08) doped with fluorinated 9,9′-bianthracene derivatives (fluorophores)
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A series of new fluorinated 9,9′-bianthracene derivatives (BAnFs) have been designed and synthesized to serve as deep-blue dopants in organic electroluminescent (EL) devices. With the different substitution patterns of the electron-withdrawing groups, such as F and CF3, the photophysical properties, the energy levels and thermal stability of these BAnFs are tuned, which are supported by a density functional study of their geometry and electronic structure. In the thin film state, the fluorescent emissions of the BAnFs are fine-tuned from 448 to 439 nm, with varied fluorinated phenyl rings attached to the 9,9′-bianthracene core. All the BAnFs show a considerable thermal stability, which have high Tg values, above 150 °C. A pure blue emission at the Commission Internationale de l'Eclairage (CIE) coordinates (0.156, 0.083), has been achieved using the host 4,4′-bis(N-carbazolyl)biphenyl (CBP) doped with 10,10′-bis(3,5- bis(trifluoromethyl)phenyl)-9,9′-bianthracene (BAn-(3,5)-CF3). The maximum current efficiency and power efficiency of the BAn-(3,5)-CF 3-doped device are 3.05 cd A-1 and 2.62 lm W-1, corresponding to 5.02% of the maximum external quantum efficiency. The synthesized new fluorinated 9,9′-bianthracene derivatives show potential applications as highly efficient pure blue emitters for organic light emitting devices.
- Yu, Yue,Wu, Zhaoxin,Li, Zhanfeng,Jiao, Bo,Li, Lu,Ma, Lin,Wang, Dongdong,Zhou, Guijiang,Hou, Xun
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p. 8117 - 8127
(2014/01/06)
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- Process for Syntheis of 10,10-Dibromo-9,9-dianthracene
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This invention, which belongs to the field of organic electroluminesent materials synthetic technology, involves synthetic method of 10,10′-Dibromo-9,9′-bianthryl. The synthetic method is to use 9,9′-bianthryl as raw material, chlorinated hydrocarbon as solvent, bromide as bromine agent and react. This method not only produces no environmental pollution, but also enjoys high yield, therefore, it is suitable for industrial production.
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Page/Page column 2
(2012/03/27)
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- Synthesis of unnatural amino acid derivatives via palladium-catalyzed 1,4-addition of boronic acids
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Aryl and alkenyl amino acid derivatives were synthesized by a palladium-catalyzed 1,4-addition of the corresponding boronic acids to 2-acetamidoacrylate.
- Ray, Devalina,Nyong, Abijah M.,Natarajan, Amarnath
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experimental part
p. 2655 - 2656
(2010/06/19)
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- Synthesis and optical properties of novel blue fluorescent conjugated polymers
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In the present paper we describe new approaches towards the synthesis of conjugated polymers with defined conjugation length, resulting in a blue or green fluorescence. The new approach reported here is to use 1,3-phenylene (type 1) and 10,10'-bianthrylene (type 2) bridges of conjugated segments such as stilbenes and thiophenes which can easily be varied to further change the optical properties.
- Baumgarten, Martin,Yueksel, Timucin
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p. 1699 - 1706
(2007/10/03)
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- Novel oligo(9,10-anthrylene)s: Models for electron transfer and high-spin formation
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Newly synthesized soluble oligo(9,10-anthrylene)s 1 have been subjected to reduction with alkali metal. The electron paramagnetic resonance/electron nuclear double resonance (EPR/ENDOR) studies of corresponding dimer, trimer, and tetramer monoradicals demonstrate that the rate of intramolecular electron transfer between anthracene moieties sensitively depends on the special substitution pattern and the ion pair structure. These features allow for a switching from effectively delocalized to localized states. In agreement with theoretical investigations, high-spin formation of the higher charged species has been obtained. The maximum spin multiplicity received so far is a quintet state for the tetraanion of the tetraanthrylene. The stability of the highly charged states is proven by NMR spectroscopic investigations, where a completely reduced diamagnetic hexaanion of trianthrylene has been characterized by 1H and 13C NMR. As revealed by temperature dependent EPR measurement of the dimer dianion, the triplet state is thermally excited (signal intensity reaches a maximum at 20 K) and the zero-field splitting loses its axial character (typical for orthogonal alignment) at low temperatures, pointing to increased orthorhombicity with decreasing temperature (100-10 K). Although the ground state is singlet, the energy of the triplet state lies only 60 cal/mol above that of the singlet. Surprisingly also the higher spin states of the oligomers were found to be thermally activated with 120 cal/mol for the doublet-quartet (S = 3/2) transition and 180 cal/mol for the quintet-singlet (S = 2) transition.
- Müller, Uwe,Baumgarten, Martin
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p. 5840 - 5850
(2007/10/02)
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- Electrophilic Additions to Tetradehydrodianthracene
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5,12:6,11-Dibenzenodibenzocyclooctene (tetradehydrodianthracene, TDDA) (1) reacts with halogens to give transannular (anti) 4, 5 and ring-opened (syn) products 6, 7.The product ratio shows a remarkable solvent dependence.Solvents of medium polarity favor anti addition, whereas syn addition is observed both with increasing and decreasing polarity.For instance, chlorine in toluene adds 100percent syn, in dichloroethane 56percent anti, and in trifluoroethanol again 100percent syn.It is concluded that, depending on solvent polarity, three different mechanisms for electrophilic addition are operative. - Keywords: Electrophilic addition / Tetradehydrodianthracene / Solvent effects
- Herges, Rainer,Neumann, Helfried
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p. 1283 - 1290
(2007/10/02)
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- Photochemical Reactions of Bromoanthracenes with N,N-Dimethylaniline in Solution
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Major products of the photolysis of 9-bromoanthracene and 9,10-dibromoanthracene in benzene and acetonitrile as well as photochemical reaction products of the two bromoanthracenes with N,N-dimethylaniline in these solvents have been isolated and identified.The mechanisms of partial reactions are discussed and attention is paid to the medium effect on the photochemical transformations. - Keywords: Photochemical Reactions, Bromoanthracenes
- Fulara, Jan,Latowski, Tadeusz
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p. 846 - 851
(2007/10/02)
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