35335-16-1Relevant articles and documents
β-Strand inspired bifacial π-conjugated polymers
Chaudhuri, Saikat,Mohanan, Manikandan,Willems, Andreas V.,Bertke, Jeffery A.,Gavvalapalli, Nagarjuna
, p. 5976 - 5982 (2019)
Access to diverse, relatively high molecular weight soluble linear polymers without pendant solubilizing chains is the key to solution state synthesis of structurally diverse nanoribbons of conjugated materials. However, realizing soluble 1D-π-conjugated polymers without pendant solubilizing chains is a daunting task. Herein, inspired from the polypeptide β-strand architecture, we have designed and developed novel bifacial π-conjugated polymers (Mn: ca. 24 kDa) that are soluble (ca. 70 to >250 mM) despite the absence of pendant solubilizing chains. The impact of varying the bifacial monomer height on polymer solubility, optical properties, and interactions with small molecules is reported.
Synthesis of Ultrafine and Highly Dispersed Metal Nanoparticles Confined in a Thioether-Containing Covalent Organic Framework and Their Catalytic Applications
Lu, Shuanglong,Hu, Yiming,Wan, Shun,McCaffrey, Ryan,Jin, Yinghua,Gu, Hongwei,Zhang, Wei
, p. 17082 - 17088 (2017)
Covalent organic frameworks (COFs) with well-defined and customizable pore structures are promising templates for the synthesis of nanomaterials with controllable sizes and dispersity. Herein, a thioether-containing COF has been rationally designed and used for the confined growth of ultrafine metal nanoparticles (NPs). Pt or Pd nanoparticles (Pt NPs and Pd NPs) immobilized inside the cavity of the COF material have been successfully prepared at a high loading with a narrow size distribution (1.7 ± 0.2 nm). We found the crystallinity of the COF support and the presence of thioether groups inside the cavities are critical for the size-controlled synthesis of ultrafine NPs. The as-prepared COF-supported ultrafine Pt NPs and Pd NPs show excellent catalytic activity respectively in nitrophenol reduction and Suzuki-Miyaura coupling reaction under mild conditions and low catalyst loading. More importantly, they are highly stable and easily recycled and reused without loss of their catalytic activities. Such COF-supported size-controlled synthesis of nanoparticles will open a new frontier on design and preparation of metal NP@COF composite materials for various potential applications, such as catalysis and development of optical and electronic materials.
Synthesis and optical properties of light-emitting polyfluorene derivatives
Aiamsen, Philaiwan,Carroll, David L.,Phanichphant, Sukon
, p. 428 - 435 (2011)
The emitting-polymers, Polyfluorene (PF) and Poly(fluorene- benzothiadiazole-quinoline) [PF-BT-QL], have been synthesized by the Suzuki coupling reactions. The properties of polymers were characterized using UV-Vis spectroscopy, GPC, DSC, TGA, Photoluminescence (PL), Fluoresence (FL), Electroluminescence (EL) spectroscopy. The synthetic polymers were soluble in common organic solvents and easily spin-coated onto the indium-tin oxide (ITO)-coated glass substrates. Light-emitting devices (LEDs) with ITO/PEDOT:PSS/polymer/LiF/Al configuration were fabricated, and the devices using copolymers showed red shift EL spectra relative to that of PF. The turns on voltages of copolymers were lower than that of PF. Copyright Taylor & Francis Group, LLC.
Synthesis and structure of the bimetallic organoantimony catalyst and its application in diastereoselective direct Mannich reaction as facile separation catalytic system
Tang, Niu,Song, Xingxing,Yang, Tianbao,Qiu, Renhua,Yin, Shuang-Feng
, (2021/04/27)
A bimetallic organoantimony catalyst with four Lewis/Br?nsted acidic/basic sites assembled orderly was successfully synthesized and showed high catalytic efficiency. It has been applied in diastereoselective direct Mannich reaction by adding 0.1 mol% catalyst. This reaction presented unexpected facile separation ability from homogenous solution to heterogeneous solution.
Rational design, facile synthesis, and linear/nonlinear optical properties of novel two-photon absorption stilbene derivatives with different configurations
Cai, Zhi-Bin,Dai, Huan,Li, Sheng-Li,Lou, Qiao-Xian,Tian, Yu-Peng
, (2021/08/18)
Four novel two-photon absorption compounds (1MOBI, 2MOHA, 3BrBI, and 4BrHA), which have assembled stilbene π-bridge, different electron acceptors and donors, were synthesized conveniently via the one-step Horner-Wadsworth-Emmons reaction. Their configurations are A-π-D-π-A, D′-π-D-π-D′, A′-π-A-π-A′, and D-π-A-π-D, respectively. Their linear and nonlinear optical properties including linear absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence, were systematically investigated in various solvents. The results demonstrate that the compounds with dihexylamino donors exhibit good optical properties. 2MOHA and 4BrHA exhibit large two-photon absorption cross-sections (2183 and 1737 GM) in DMF, which are larger than those of many known stilbene derivatives. The relationships between the structures and the optical properties were studied aided with the time-dependent density functional theory calculations.
Nonplanar Tub-Shaped Benzocyclooctatetraenes via Halogen-Radical Ring Opening of Dihydrobiphenylenes
Bello-Garciá, Jesús,Padín, Damián,Saá, Carlos,Varela, Jesús A.
supporting information, p. 5539 - 5544 (2021/07/26)
A novel tandem Ru-catalyzed [2+2+2] cycloaddition of arylenynes to dihydrobiphenylenes followed by halogen-radical ring opening has been developed for the construction of tub-shaped halogenated benzocyclooctatetraenes (bCOT's). Cross-couplings and Diels-Alder reactions of the brominated bCOT's allow the formation of the corresponding eight-membered ring-fused PAH's. The halogen-radical ring opening probably occurs via a selective formation of a bis-allyl radical at the 1,3-cyclohexadiene moiety, halogenation at the bridgehead carbon, and finally electrocyclic ring opening.
“Golden” Cascade Cyclization to Benzo[c]-Phenanthridines
Hendrich, Christoph M.,Senn, Sebastian,Haas, Lea,Hoffmann, Marvin T.,Zschieschang, Ute,Greiner, Luca C.,Rominger, Frank,Rudolph, Matthias,Klauk, Hagen,Dreuw, Andreas,Hashmi, A. Stephen K.
supporting information, p. 14778 - 14784 (2021/09/14)
Herein, we describe a gold-catalyzed cascade cyclization of Boc-protected benzylamines bearing two tethered alkyne moieties in a domino reaction initiated by a 6-endo-dig cyclization. The reaction was screened intensively, and the scope was explored, resulting in nine new Boc-protected dihydrobenzo[c]phenanthridines with yields of up to 98 %; even a π-extension and two bidirectional approaches were successful. Furthermore, thermal cleavage of the Boc group and subsequent oxidation gave substituted benzo[c]phenanthridines in up to quantitative yields. Two bidirectional approaches under the optimized conditions were successful, and the resulting π-extended molecules were tested as organic semiconductors in organic thin-film transistors.
Synthesis and photophysics of new pyridyl end-capped 3D-dithia[3.3]paracyclophane-based Janus tectons: Surface-confined self-assembly of their model pedestal on HOPG
Attias, A.-J.,Auffray, M.,Charra, F.,Kreher, D.,Mathevet, F.,Sosa Vargas, L.
, p. 7665 - 7674 (2020/06/10)
Surface-confined supramolecular self-assembly is currently a promising strategy to create well-organised 2D-networks on conducting surfaces. However, using such substrates tends to quench any electronic properties of the adsorbed molecules. In this context, new pyridyl end-capped 3D-dithia[3.3]paracyclophane-based molecules were designed, along with their model compound (pedestal), with the objective of self-assembling these tectons on any substrate. The synthesis of these new molecules was not straightforward and is consequently described in detail. Once the materials were successfully isolated, their optoelectronic properties were investigated to study potential non-covalent interactions: through pH-dependent absorption and emission measurements, and infra-red spectrometry. We evidenced that both ionic bonding and coordination bonding are compatible with the molecules design. Finally, preliminary scanning tunneling microscopy (STM) studies were performed to study the supramolecular self-assembly properties of the model lower-deck (pedestal) on highly oriented pyrolytic graphite (HOPG): we observed a quasi-square lattice of self-assembled 2D-networks that appear to form independently of the underlying HOPG lattice.
A high efficiency pure organic room temperature phosphorescence polymer PPV derivative for OLED
He, Ying,Cheng, Nianhe,Xu, Xin,Fu, Jiawei,Wang, Jun-an
, p. 247 - 251 (2018/11/30)
For the purpose of improving device efficiency and reducing cost, it is necessary to develop pure organic molecules with room temperature phosphorescence (RTP). A high efficiency pure organic RTP polymer, poly-p-phenylene vinylene (PPV) derivative (Br-PPV-CHO), was designed and synthesized, which possesses a blue emission at 496 nm, an emission lifetime of 14.1 μs, and a photoluminescence quantum yield of 12.2%, and the HOMO and LUMO of ?5.35 eV and ?2.75 eV, respectively, showing a great potential application in the emitting layer of OLED. A device fabricated with the PPV derivative as the emitting material layer shows a max luminance of 194 cd/m2 when the Br-PPV-CHO content was 0.5 wt %, demonstrating the best RTP performance. The good properties of Br-PPV-CHO come from the substituent groups of bromine and aromatic aldehyde, and the molecular structure design strategy in the PPV derivative supplies a useful guidance for the design and syntheses of organic RTP materials.
An N-heterocyclic carbene-functionalised covalent organic framework with atomically dispersed palladium for coupling reactions under mild conditions
Yang, Junjuan,Wu, Yuanyuan,Wu, Xiaowei,Liu, Wenjing,Wang, Yaofang,Wang, Junwen
, p. 5267 - 5273 (2019/10/11)
Covalent organic frameworks (COFs) are a new class of crystalline porous materials that could function as excellent scaffolds for heterogeneous catalysts. Herein, we report a functionalised COF (COF-NHC) using N-heterocyclic carbene (NHC) as a monomer building block via a facile ionothermal strategy. The simple and easily prepared imine-linked COF-NHC possessed two coordination sites (NHC and amine), which could fix the active component (Pd) tightly in COF, leading to atomically dispersed Pd in a heterogeneous catalyst. The as-prepared Pd@COF-NHC showed high stability in the Suzuki-Miyaura coupling reaction of arylboronic acids and aryl halides in aqueous media at room temperature, and could be easily recycled and reused multiple times without the loss of catalytic activity. Moreover, C-C coupling reactions could be accomplished using triarylbismuth reagents in ethanol aqueous solutions with high yields.
