- Synthesis of Doubly Annulated m-Terphenyl-Based Molecular Tweezers and Their Charge-Transfer Complexes with DDQ as a Guest
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The synthesis of a doubly-annulated m-terphenyl-based tweezer platform has been developed, which affords ready incorporation of various pincer units from monobenzenoid to polybenzenoid electron donors. The complexation study with 2,3-dichloro-5,6-dicyano-
- Thakur, Khushabu,Wang, Denan,Lindeman, Sergey V.,Rathore, Rajendra
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- Polymorphism of 2D Imine Covalent Organic Frameworks
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We designed and synthesized A2B2 type tetraphenyl benzene monomers (p-, m-, and o-TetPB) which have the para-, meta, and ortho-substituted isomeric structures, for the direct construction of isomeric frameworks. Interestingly, both kagome (kgm) and monoclinic square (sql) framework isomers are produced from either p-TetPB (C2h symmetry) or m-TetPB (C2v symmetry) by changing reaction solvents, while their isomeric structures are characterized by X-ray diffraction, computational simulation, microscopy, and sorption isotherm measurements. Only sql frameworks was formed for o-TetPB (C2v symmetry), irrespective of reaction solvents. These results disclose a unique feature in the framework structural formation, that is, the geometry of monomers directs and dominates the lattice growth process while the solvent plays a role in the perturbation of chain growth pattern. The isomeric frameworks exhibit highly selective adsorption of vitamin B12 owing to pore shape and size differences.
- Li, Yusen,Guo, Linshuo,Lv, Yongkang,Zhao, Ziqiang,Ma, Yanhang,Chen, Weihua,Xing, Guolong,Jiang, Donglin,Chen, Long
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supporting information
p. 5363 - 5369
(2021/01/20)
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- Gold-Catalyzed Synthesis of π-Extended Carbazole-Based Systems and their Application as Organic Semiconductors
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Herein we describe a gold-catalyzed bidirectional synthesis of N-heteropolycyclic compounds bearing carbazole moieties – namely π-extended benzodicarbazoles and π-extended indolocarbazoles. Overall, four previously unknown core structures were synthesized. This approach is convergent, modular and the gold-catalyzed key step comprises of a cascade reaction starting from stable di-azido compounds. The obtained molecules were fully characterized and their optical and electronic properties as well as their performance in organic thin-film transistors generated by vacuum deposition were studied. Charge-carrier mobilities of up to 0.3 cm2/Vs were measured. (Figure presented.).
- Hendrich, Christoph M.,Hannibal, Valentin D.,Eberle, Lukas,Hertwig, Leif E.,Zschieschang, Ute,Rominger, Frank,Rudolph, Matthias,Klauk, Hagen,K. Hashmi, A. Stephen
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supporting information
p. 1401 - 1407
(2021/02/03)
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- Precise Monoselective Aromatic C-H Bond Activation by Chemisorption of Meta-Aryne on a Metal Surface
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Aromatic C-H bond activation has attracted much attention due to its versatile applications in the synthesis of aryl-containing chemicals. The major challenge lies in the minimization of the activation barrier and maximization of the regioselectivity. Here, we report the highly selective activation of the central aromatic C-H bond in meta-aryne species anchored to a copper surface, which catalyzes the C-H bond dissociation. Two prototype molecules, i.e., 4′,6′-dibromo-meta-terphenyl and 3′,5′-dibromo-ortho-terphenyl, have been employed to perform C-C coupling reactions on Cu(111). The chemical structures of the resulting products have been clarified by a combination of scanning tunneling microscopy and noncontact atomic force microscopy. Both methods demonstrate a remarkable weakening of the targeted C-H bond. Density functional theory calculations reveal that this efficient C-H activation stems from the extraordinary chemisorption of the meta-aryne on the Cu(111) surface, resulting in the close proximity of the targeted C-H group to the Cu(111) surface and the absence of planarity of the phenyl ring. These effects lead to a lowering of the C-H dissociation barrier from 1.80 to 1.12 eV, in agreement with the experimental data.
- Fan, Qitang,Werner, Simon,Tschakert, Jalmar,Ebeling, Daniel,Schirmeisen, André,Hilt, Gerhard,Hieringer, Wolfgang,Gottfried, J. Michael
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supporting information
p. 7526 - 7532
(2018/05/25)
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- HETEROACENE DERIVATIVE, ORGANIC SEMICONDUCTOR LAYER, AND ORGANIC THIN FILM TRANSISTOR
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PROBLEM TO BE SOLVED: To provide a novel heteroacene derivative being a coating type organic semiconductor material with high carrier mobility, high solubility and high oxidation resistance; and an organic semiconductor layer and an organic thin film tran
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Paragraph 0085
(2018/04/11)
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- Heteroacene derivative, the organic semiconductor layer, and an organic thin film transistor (by machine translation)
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[Problem] high carrier mobility, high oxidation resistance and high solubility in a coating type organic semiconductor material having a new heteroacene derivatives, organic thin-film transistor using an organic semiconductor layer. In the general formula
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Paragraph 0083
(2018/05/03)
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- Improved and new syntheses of potential molecular electronics devices
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New syntheses of ethyl and nitro substituted oligo(phenylene ethynylene)s (OPEs) have been developed. To further explore whether the presence of nitro functionality in OPEs leads to switching and memory capabilities, new nitro substituted OPEs have been designed and synthesized. An isatogen-based system, a structure that is isomeric to the nitro OPE, has been synthesized. Additionally, pyridine-based and chromium-based compounds have been synthesized. We surmise that redox reactions of these candidates may impart switching capabilities and electrochemical studies are shown. U-shaped OPEs were synthesized to inhibit leakage of metals deposited during formation of top contacts on self-assembled monolayers (SAMs). The OPEs contain either thiol-based moieties or isonitrile groups to enable formation of SAMs on metal substrates.
- Price Jr., David W.,Dirk, Shawn M.,Maya, Francisco,Tour, James M.
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p. 2497 - 2518
(2007/10/03)
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- Functionalizable polycyclic aromatics through oxidative cyclization of pendant thiophenes
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We present a general strategy for obtaining large sulfur-containing polycyclic aromatics from thienyl precursors through iron(Ill) chloride mediated oxidative cyclizations. By placing thienyl moieties in close proximity to adjacent arenes, we have directed the oxidized intermediates into controlled cyclization pathways, effectively suppressing polymer formation. Utilizing these cyclized compounds and their thienyl precursors, we have studied cyclization/polymerization pathways of polymers such as poly(2). The unsubstituted positions α to the sulfur atoms within these aromatic cores allowed for efficient halogenation and further functionalization. As a demonstration, we prepared a series of arylene-ethynylene polymers with varying degrees of chromophore aromatization and used them to probe the effects of synthetically imposed rigidity on polymer photophysical behavior. The symmetries and effective conjugation pathways within the monomers play a key role in determining photophysical properties. We observed that rigid, aromatized chromophores generally led to increased excited-state lifetimes by decreasing radiative rates of fluorescence decay.
- Tovar, John D.,Rose, Aimee,Swager, Timothy M.
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p. 7762 - 7769
(2007/10/03)
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- Directed electrophilic cyclizations: Efficient methodology for the synthesis of fused polycyclic aromatics
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A versatile method for the synthesis of complex, fused polycyclic aromatic systems in high chemical yield is described. Construction is achieved using a general two-step synthetic sequence. Pd-catalyzed Suzuki and Negishi type cross-coupling chemistries allow for the preparation of nonfused skeletal ring systems in yields consistently >80%. The critical ring-forming step, which generally proceeds in very high to quantitative yield, utilizes 4-alkoxyphenylethynyl groups and is induced by strong electrophiles such as trifluoroacetic acid and iodonium tetrafluoroborate. The reaction in essence produces phenanthrene moieties which are integrated into extended polycyclic aromatic structures. Fused polycyclic benzenoids as well as benzenoid/thiophene systems may be prepared utilizing this methodology. The scope of the described cross-coupling/cyclization chemistry including mechanistic insights and problematic side reactions are described.
- Goldfinger, Marc B.,Crawford, Khushrav B.,Swager, Timothy M.
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p. 4578 - 4593
(2007/10/03)
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- Synthetically Useful Aryl-Aryl Bond Formation via Grignard Generation and Trapping of Arynes. A One Step Synthesis of p-Terphenyl and Unsymmetric Biaryls
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A one-pot route to p-terphenyls is described.Addition of 1,4-dibromo-2,5-diiodobenzene, 1, to excess aryl Grignard reagent gives the terphenyl di-Grignard 2 and the trihalo mono-Grignard 5.After aqueous quench, p-terphenyls are isolated in 30percent to 50percent yield (Table I).This yield can be improved to 70-80percent by adding potassium tert-butoxide or lithium tetramethylpiperidide to the reaction mixture prior to workup.Mechanisms involving organometallic aryne intermediates are proposed.With o-bromoiodoarenes in place of tetrahaloarenes the method can be adapted to prepare unsymmetric biaryls in good yield (Table II).
- Hart, Harold,Harada, Katsumasa,Du, Chi-Jen Frank
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p. 3104 - 3110
(2007/10/02)
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- A NEW SYNTHESIS OF PARA-TERPHENYLS
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A new, one-step synthesis of para-terphenyls from aryl Grignards and 1,4-dibromo-2,5-diiodobenzene 1 as a di-aryne equivalent is described.
- Hart, Harold,Harada, Katsumasa
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