10016-52-1Relevant articles and documents
Alumina-promoted oxodefluorination
Amsharov, Konstantin,Mikhail, Feofanov,Vladimir, Akhmetov
, p. 10879 - 10882 (2020)
A simple protocol for the clean preparation of heterocyclic compounds containing dibenzofuran's core via oxodefluorination of fluoroarenes on activated γ-Al2O3 is reported. Alumina can be considered as a reliable oxygen source enabling one-pot substitution of fluorine atoms and yielding benzoannulated furan derivatives. The corresponding C-F bond activation is selective towards less stable C-Br/C-I and occurs under metal- A nd solvent-free conditions.
Photophysical properties and optical power limiting ability of Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at different positions
Tian, Zhuanzhuan,Yang, Xiaolong,Liu, Boao,Zhong, Daokun,Zhou, Guijiang
, p. 28 - 36 (2019)
Two series of Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at different positions have been synthesized. In the absorption spectra, the Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 3,6-position have blue-shift with respect to the corresponding analogs bearing fluorene-type ligands with ethynyl units at 2,7-position, showing better transparency in the visible light region. Moreover, the Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 3,6-position show stronger triplet emission than corresponding analogs bearing fluorene-type ligands with ethynyl units at 2,7-position in the photoluminescent (PL) spectra. Furthermore, these Pt(II) polyynes were applied to optical power limiting (OPL) field. The Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 2,7-position show better OPL performance than the corresponding analogs with fluorene-type ligands of ethynyl units at 3,6-position. Therefore, changing the position of the ethynyl units in fluorene-type ligands can not only effectively control the photophysical properties of the Pt(II) polyynes, but also has an important effect on their OPL ability.
Catalyst-Free Synthesis of O-Heteroacenes by Ladderization of Fluorinated Oligophenylenes
Feofanov, Mikhail,Akhmetov, Vladimir,Takayama, Ryo,Amsharov, Konstantin
, p. 5199 - 5203 (2021)
A novel catalyst-free approach to benzoannulated oxygen-containing heterocycles from fluorinated oligophenylenes is reported. Unlike existing methods, the presented reaction does not require an oxygen-containing precursor and relies on an external oxygen source, potassium tert-butoxide, which serves as an O2? synthon. The radical nature of the reaction facilitates nucleophilic substitution even in the presence of strong electron-donating groups and enables de-tert-butylation required for the complete annulation. Also demonstrated is the applicability of the method to introduce five-, six-, and seven-membered rings containing oxygen, whereas multiple annulations also open up a short synthetic path to ladder-type O-heteroacenes and oligodibenzofurans.
A Family of Superhelicenes: Easily Tunable, Chiral Nanographenes by Merging Helicity with Planar π Systems
Amsharov, Konstantin Y.,B?nisch, Simon,G?rling, Andreas,Guldi, Dirk M.,Haines, Philipp,Hampel, Frank,Jelfs, Kim E.,Jux, Norbert,Nelson, Jenny,Reger, David,Schmidt, Julia A.,Ullrich, Tobias
, p. 18073 - 18081 (2021)
We designed a straightforward synthetic route towards a full-fledged family of π-extended helicenes: superhelicenes. They have two hexa-peri-hexabenzocoronenes (HBCs) in common that are connected via a central five-membered ring. By means of structurally altering this 5-membered ring, we realized a versatile library of molecular building blocks. Not only the superhelicene structure, but also their features are tuned with ease. In-depth physico-chemical characterizations served as a proof of concept thereof. The superhelicene enantiomers were separated, their circular dichroism was measured in preliminary studies and concluded with an enantiomeric assignment. Our work was rounded-off by crystal structure analyses. Mixed stacks of M- and P-isomers led to twisted molecular wires. Using such stacks, charge-carrier mobilities were calculated, giving reason to expect outstanding hole transporting properties.
Simple and efficient synthesis of various dibenzofuran carbaldehydes
Yempala, Thirumal,Cassels, Bruce K.
, p. 1909 - 1915 (2016)
We herein report simple and efficient methods for the synthesis of various formyl derivatives of dibenzofuran. The aldehydes reported are prepared in at most three steps and in yields greater than 60% from commercially available dibenzofuran, with one exception where isomers must be separated. The protocols described involve either formylation of previously functionalized dibenzofuran derivatives or the initial introduction of the formyl group and subsequent further functionalization under standard reaction conditions as described. We have also reported an efficient and simple method for the synthesis of key methoxydibenzofurans in high yield (65% overall for two steps).
Structural controlled pure metallo-triangular assembly through bisterpyridinyl Dibenzo[b,d]thiophene, Dibenzo[b,d]furan and Dibenzo[b,d]carbazole
Liu, Qianqian,Yang, Xiaoyu,Wang, Meng,Liu, Die,Chen, Mingzhao,Wu, Tun,Jiang, Zhiyuan,Wang, Pingshan
, p. 2400 - 2405 (2019)
A novel family of metallocycles was constructed by a one-pot self-assembly of three analogous bis(terpyridine) ligand monomers L1-L3, having different bent angles, with metal ions (Zn2+ or Cd2+). The dibenzo[b,d]thiophene-containing ligand L3 assembled with the metal ions to form a single trimer, whereas the dibenzo[b,d]furan-containing ligand L2 and dibenzo[b,d]carbazole-containing ligand L1 formed a mixture of trimers and tetramers. Heteroatoms (N, O, S) significantly contributed to the molecular size of the assemblies, owing to the bent angle of the bis-terpyridines ligands.
Dibenzofuran derivatives with meta- and para-triphenylamine substituents as hole-transporting materials in organic light-emitting devices
Yun, Seong-Jae,Seo, Min Hye,Lee, Sungkoo
, (2020)
Three novel hole-transporting materials, 3,3'-(dibenzo[b,d]furan-2,8-diyl)bis(N,N-diphenylaniline) (BF-m-TPA), 4,4'-(dibenzo[b,d]furan-2,8-diyl)bis(N,N-diphenylaniline) (BF-p-TPA) and 4,4'-(dibenzo[b,d]furan-2,6-diyl)bis(N,N-diphenylaniline) (BF-2,6-TPA), were designed and synthesized. Owing to the rigid dibenzofuran core, these BF-TPA derivatives exhibited high thermal decomposition temperatures of over 395 °C and very high LUMO energy levels. Electroluminescent (EL) devices were fabricated using these three hole-transporting materials. The best device performance was obtained for BF-m-TPA, with the maximum luminance (L) of 15,230 cd/m2, luminance efficiency (LE) of 56.5 cd/A, power efficiency (PE) of 13.3 lm/W, and external quantum efficiency (EQE) of 16.3%.
Blue to light gray electrochromic polymers from dodecyl-derivatized thiophene Bis-substituted dibenzothiophene/dibenzofuran
Lin, Kaiwen,Zhao, Yao,Ming, Shouli,Liu, Hongtao,Zhen, Shijie,Xu, Jingkun,Lu, Baoyang
, p. 1468 - 1478 (2016)
3-Dodecylthiophene end-capped two monomers: 2,8-bis-(4-dodecyl-thiophen-2-yl)-dibenzothiophene (DBT-3DTh) and 2,8-bis-(4-dodecyl-thiophen-2-yl)-dibenzofuran (DBF-3DTh) were synthesized via Stille coupling reaction. Both monomers exhibited emission peaks at about 400 nm with fluorescence quantum yields ranging from 0.16 to 0.21. The corresponding electroactive polymers poly(2,8-bis-(4-dodecyl-thiophen-2-yl)-dibenzothiophene) (PDBT-3DTh) and poly(2,8-bis-(4-dodecyl-thiophen-2-yl)-dibenzofuran) (PDBF-3DTh) were obtained by electropolymerization method and displayed good electrochemical stability. Both polymers switched between light gray in the neutral state and blue in the oxidized state. Kinetic investigations showed that PDBT-3DTh exhibited a maximum optical contrast (ΔT %) of 25.23% at 575 nm with the coloration efficiency (CE) of 196 cm2 C-1. However, the electrochromic properties of PDBF-3DTh were inferior to PDBT-3DTh. Further detailed discussions with EDOT and 3-alkylthiophenes end-capped DBT/DBF hybrid electrochromic polymers were comparatively studied.
Triptycenyl Sulfide: A Practical and Active Catalyst for Electrophilic Aromatic Halogenation Using N-Halosuccinimides
Nishii, Yuji,Ikeda, Mitsuhiro,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
supporting information, p. 1621 - 1629 (2020/02/04)
A Lewis base catalyst Trip-SMe (Trip = triptycenyl) for electrophilic aromatic halogenation using N-halosuccinimides (NXS) is introduced. In the presence of an appropriate activator (as a noncoordinating-anion source), a series of unactivated aromatic compounds were halogenated at ambient temperature using NXS. This catalytic system was applicable to transformations that are currently unachievable except for the use of Br2 or Cl2: e.g., multihalogenation of naphthalene, regioselective bromination of BINOL, etc. Controlled experiments revealed that the triptycenyl substituent exerts a crucial role for the catalytic activity, and kinetic experiments implied the occurrence of a sulfonium salt [Trip-S(Me)Br][SbF6] as an active species. Compared to simple dialkyl sulfides, Trip-SMe exhibited a significant charge-separated ion pair character within the halonium complex whose structural information was obtained by the single-crystal X-ray analysis. A preliminary computational study disclosed that the πsystem of the triptycenyl functionality is a key motif to consolidate the enhancement of electrophilicity.
3, 5 - dipyridyl phenyl derivatives, and electron transport material comprising an organic electroluminescent device using same
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Paragraph 0036-0037, (2017/03/18)
PROBLEM TO BE SOLVED: To provide an electron transport material having a novel 3,5-dipyridyl phenyl derivative exhibiting electronic transport property, maintaining high triplet energy, excellent in electron injection property, hole block property and heat characteristic, and useful for a high-efficient phosphorescence organic EL element, and to provide an organic EL element using the same.SOLUTION: There is provided an element having a layer containing 3,5-dipyridyl phenyl derivative represented by the following formula (1) in an organic EL element made by laminating at least one organic layer between a pair of elements. In the formula, X, Rto Rand Rto Rare groups selected from a specific group independently.
