- Chiral Dibenzopentalene-Based Conjugated Nanohoops through Stereoselective Synthesis
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Conjugated nanohoops allow to investigate the effect of radial conjugation and bending on the involved π-systems. They can possess unexpected optoelectronic properties and their radially oriented π-system makes them attractive for host–guest chemistry. Be
- Hermann, Mathias,Wassy, Daniel,Kohn, Julia,Seitz, Philipp,Betschart, Martin U.,Grimme, Stefan,Esser, Birgit
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p. 10680 - 10689
(2021/04/02)
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- Aggregation induced emission-emissive stannoles in the solid state
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The optoelectronic and structural properties of six stannoles are reported. All revealed extremely weak emission in solution at 295 K, but intensive fluorescence in the solid state with quantum yields (ΦF) of up to 11.1% in the crystal, and of up to 24.4% (ΦF) in the thin film.
- Lork, Enno,Ramirez Y Medina, Isabel-Maria,Rohdenburg, Markus,Staubitz, Anne
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supporting information
p. 9775 - 9778
(2020/09/07)
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- Synthesis method of p-bromo-linear alkylbenzene
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The invention belongs to the technical field of fine chemical industry, and in particular discloses a clean and efficient synthetic process technology of p-bromo-linear alkylbenzene. Paradibromobenzene and linear chain 1-haloalkane are added into an organic solvent, and reaction is conducted under the action of a catalyst ferric acetylacetonate and an activating agent consisting of zinc halide and magnesium powder to obtain the p-bromo-linear alkylbenzene. A paradibromobenzene single coupling technology is adopted, so production of ortho/meta isomers which are difficult to separate is avoided from the source; a Grignard reagent, which is instable to water and air, or an expensive boric acid reagent intermediate is not used, so that the production cost is reduced; a one-pot reaction technology is adopted, so that operation is simplified and good industrial application value is achieved.
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Paragraph 0035; 0053
(2017/08/25)
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- The cobalt-catalyzed cross-coupling reaction of alkyl halides with alkyl Grignard reagents: A new route to constructing quaternary carbon centers
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The cross-coupling of alkyl (pseudo)halides with alkyl Grignard reagents is catalyzed efficiently by a cobalt(II) chloride-lithium iodide-1,3-diene catalytic system, which provides a new synthetic tool for constructing sp 3 carbon chains. This system is particularly useful for creating quaternary carbon centers via the use of tertiary alkyl Grignard reagents. Various functional groups including esters, amides and carbamates are well tolerated.
- Iwasaki, Takanori,Takagawa, Hiroaki,Okamoto, Kanako,Singh, Surya Prakash,Kuniyasu, Hitoshi,Kambe, Nobuaki
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p. 1583 - 1592
(2014/06/23)
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- Copper-catalyzed alkyl-alkyl cross-coupling reactions using hydrocarbon additives: Efficiency of catalyst and roles of additives
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Cross-coupling of alkyl halides with alkyl Grignard reagents proceeds with extremely high TONs of up to 1230000 using a Cu/unsaturated hydrocarbon catalytic system. Alkyl fluorides, chlorides, bromides, and tosylates are all suitable electrophiles, and a TOF as high as 31200 h-1 was attained using an alkyl iodide. Side reactions of this catalytic system, i.e., reduction, dehydrohalogenation (elimination), and the homocoupling of alkyl halides, occur in the absence of additives. It appears that the reaction involves the β-hydrogen elimination of alkylcopper intermediates, giving rise to olefins and Cu-H species, and that this process triggers both side reactions and the degradation of the Cu catalyst. The formed Cu-H promotes the reduction of alkyl halides to give alkanes and Cu-X or the generation of Cu(0), probably by disproportionation, which can oxidatively add to alkyl halides to yield olefins and, in some cases, homocoupling products. Unsaturated hydrocarbon additives such as 1,3-butadiene and phenylpropyne play important roles in achieving highly efficient cross-coupling by suppressing β-hydrogen elimination, which inhibits both the degradation of the Cu catalyst and undesirable side reactions.
- Iwasaki, Takanori,Imanishi, Reiko,Shimizu, Ryohei,Kuniyasu, Hitoshi,Terao, Jun,Kambe, Nobuaki
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p. 8522 - 8532
(2015/01/08)
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- Co-catalyzed cross-coupling of alkyl halides with tertiary alkyl Grignard reagents using a 1,3-butadiene additive
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The cobalt-catalyzed cross-coupling of alkyl (pseudo)halides with alkyl Grignard reagents in the presence of 1,3-butadiene as a ligand precursor and LiI is described. Sterically congested quaternary carbon centers could be constructed by using tertiary alkyl Grignard reagents. This reaction proceeds via an ionic mechanism with inversion of stereochemistry at the reacting site of the alkyl halide and is compatible with various functional groups. The use of both 1,3-butadiene and LiI was essential for achieving high yields and high selectivities.
- Iwasaki, Takanori,Takagawa, Hiroaki,Singh, Surya P.,Kuniyasu, Hitoshi,Kambe, Nobuaki
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supporting information
p. 9604 - 9607
(2013/07/26)
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- Solution processable symmetric 4-alkylethynylbenzene end-capped anthracene derivatives
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New candidates composed of anthracene and 4-alkylethynylbenzene end-capped oligomers for OTFTs were synthesized under Sonogashira coupling reaction conditions. All oligomers were characterized by FT-IR, mass, UV-visible, and PL emission spectrum analyses, cyclic voltammetry (CV), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), 1H-NMR, and 13C-NMR. Investigation of their physical properties showed that the oligomers had high oxidation potential and thermal stability. Thin films of DHPEAnt and DDPEAnt were characterized by spin coating them onto Si/SiO 2 to fabricate top-contact OTFTs. The devices prepared using DHPEAnt and DDPEAnt showed hole field-effect mobilities of 4.0 × 10-3 cm2/Vs and 2.0 × 10-3 cm2/Vs, respectively, for solution-processed OTFTs.
- Jang, Sang Hun,Kim, Hyunjin,Hwang, Min Ji,Jeong, Eun Bin,Yun, Hui Jun,Lee, Dong Hoon,Kim, Yun-Hi,Park, Chan Eon,Yoon, Yong-Jin,Kwon, Soon-Ki,Lee, Sang-Gyeong
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p. 541 - 548
(2012/05/05)
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- NOVEL ORGANIC SEMICONDUCTOR COMPOUND, AND ORGANIC THIN FILM TRANSISTOR USING THE SAME
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The present invention relates to novel mono- molecular organic semiconductor compounds and organic thin film transistors comprising the same. The organic semiconductor compounds according to the present invention are characterized by a structure of an acene derivative substituted with acetylene groups at both ends, a structure of anthracene derivative substituted with acetylene groups, or a structure of a multi-nuclear aromatic derivative functionalized by naphthalene having an electron-donor substituent at both ends.
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- Linearly polarised organic light-emitting diodes (OLEDs): Synthesis and characterisation of a novel hole-transporting photoalignment copolymer
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We describe the synthesis and characterisation of a novel hole transporting photoalignment copolymer for linearly polarised emission. The copolymer has a coumarin side-chain which undergoes (2 + 2) cycloaddition on irradiation with ultraviolet light. A fluorene side-chain, whose ionisation potential is well matched to the work-function of indium tin oxide, provides hole transporting properties. Polarised green electroluminescence was obtained by spin coating a novel polymerisable and light-emitting liquid crystal onto the photoaligned copolymer. A polarisation ratio value of 13 : 1 and a polarised irradiance of 200 cd m-2 was obtained at 9 V. Polarised red emission is also described in a guest-host configuration. The spatial patterning of the polarisation direction is also shown. The Royal Society of Chemistry 2005.
- Aldred, Matthew P.,Vlachos, Panos,Contoret, Adam E. A.,Farrar, Simon R.,Chung-Tsoi,Mansoor, Bassam,Woon, Kai L.,Hudson, Robert,Kelly, Stephen M.,O'Neill, Mary
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p. 3208 - 3213
(2007/10/03)
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- Pd-Catalyzed Cross-Coupling Reaction of Alkyl Tosylates and Bromides with Grignard Reagents in the Presence of 1,3-Butadiene
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A new method for cross-coupling reaction of alkyl tosylates and bromides with Grignard reagents has been developed by the use of Pd(acac)2 or PdCl2 as the catalyst. Addition of 1,3-butadiene is essential to afford good yields of coupling products. This reaction proceeds efficiently at room temperature using primary and secondary alkyl and aryl Grignard reagents.
- Terao, Jun,Naitoh, Yoshitaka,Kuniyasu, Hitoshi,Kambe, Nobuaki
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p. 890 - 891
(2007/10/03)
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- Nickel-catalyzed cross-coupling reaction of Grignard reagents with alkyl halides and tosylates: Remarkable effect of 1,3-butadienes
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A new method for the cross-coupling reaction of Grignard reagents with alkyl chlorides, bromides, and tosylates has been developed by the use of a nickel catalyst in the presence of a diene as an additive. This reaction proceeds efficiently at 0-25 °C in THF using primary and secondary alkyl and aryl Grignard reagents. Nickel complexes bearing no phosphine ligands, such as NiCl2, Ni(acac)2, and Ni(COD)2, afford the coupling products in good yields, whereas NiCl2(PPh3)2 and NiCl2(dppp) were less effective. 1,3-Butadiene shows the highest activity as an additive for the present coupling reaction. A plausible reaction pathway was proposed. Copyright
- Terao, Jun,Watanabe, Hideyuki,Ikumi, Aki,Kuniyasu, Hitoshi,Kambe, Nobuaki
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p. 4222 - 4223
(2007/10/03)
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- Discotic liquid crystals of transition metal complexes, 31: Establishment of mesomorphism and thermochromism of bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel complexes
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Two series of bis[1,2-bis(4-n-alkylphenyl)ethane-1,2-dithiolene]nickel, Cn-Ni (n= 1-12), and bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel, CnO-Ni(n = 1-12, 14, 16, 18), have been synthesized. Their mesomorphism, thermochromism, supramolecular structures and π-acceptor property have been investigated by using different scanning calorimetry, polarizing microscopy, temperature-dependent X-ray diffraction technique, electronic spectroscopy and cyclic voltammetry. From the X-ray diffraction and electronic spectral results, it was established that the CnO-Ni complexes for n ≤ 10 exhibit two differently colored discotic lamellar (DL) mesophases whereas none of the Cn-Ni complexes has a mesophase, and that the thermochromism (brown→green) is attributable to a slow transformation from the Ni-Ni bonded dimers to the Ni-S bonded dimers.
- Horie,Takagi,Hasebe,Ozawa,Ohta
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p. 1063 - 1071
(2007/10/03)
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- Synthesis and preliminary testing of molecular wires and devices
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Presented here are several convergent synthetic routes to conjugated oligo(phenylene ethynylene)s. Some of these oligomers are free of functional groups, while others possess donor groups, acceptor groups, porphyrin interiors, and other heterocyclic interiors for various potential transmission and digital device applications. The syntheses of oligo(phenylene ethynylene)s with a variety of end groups for attachment to numerous metal probes and surfaces are presented. Some of the functionalized molecular systems showed linear, wire-like, current versus voltage (I(V)) responses, while others exhibited nonlinear I(V) curves for negative differential resistance (NDR) and molecular random access memory effects. Finally, the syntheses of functionalized oligomers are described that can form self-assembled monolayers on metallic electrodes that reduce the Schottky barriers. Information from the Schottky barrier studies can provide useful insight into molecular alligator clip optimizations for molecuar electronics.
- Tour, James M.,Rawlett, Adam M.,Kozaki, Masatoshi,Yao, Yuxing,Jagessar, Raymond C.,Dirk, Shawn M.,Price, David W.,Reed, Mark A.,Zhou, Chong-Wu,Chen, Jia,Wang, Wenyong,Campbell, Ian
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p. 5118 - 5134
(2007/10/03)
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- Preparation and Properties of Tertiary p-Alkylarylphosphines containing Straight-chain Alkyl Groups
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A series of tris(p-alkylaryl)phosphines with straight-chain alkyl groups, P(p-C6H4-CnH2n+1)3 where n=2-9, have been prepared by reaction of phosphorus trichloride with the Grignard reagent derived from the corresponding p-bromoalkylbenzene.When n=2 and 3 the phosphines are crystalline solids, but for n>3 they are viscous oils up to n=9, which is a waxy solid.The phosphines have been characterised by microanalysis, and i.r., 1H and 31P n.m.r., and mass spectrometry.The p-substituted-arylphosphines are more sensitive than triphenylphosphine to air; aerial oxidation converts them exclusively into the corresponding phosphine oxides, in contrast to trialkylphosphines which are oxidised to a complex mixture of products.The complexing ability of the new phosphines (PAr3) is demonstrated by their ready displacement of 1,5-cyclo-octadiene (cod) from (M=Pd and Pt) to yield trans- and cis-, respectively.
- Franks, Stephen,Hartley, Frank R.
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p. 2233 - 2237
(2007/10/02)
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