- Benzodipyrrole-2,6-dione-3,7-diylidenedimalononitrile Derivatives for Air-Stable n-Type Organic Field-Effect Transistors: Critical Role of N-Alkyl Substituent on Device Performance
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Benzodipyrrole-2,6-dione-3,7-diylidenedimalononitriles (BDPMs) were synthesized as active materials for the use in air-stable n-type organic field-effect transistors (OFETs), whose optical and electrochemical properties were examined. BDPM-based small molecules exhibit deep lowest unoccupied molecular orbital levels, which are required in air-stable n-type OFETs. An OFET device that was based on BDPM-But and fabricated by vapor deposition provided a maximum electron mobility of 0.131 cm2 V-1 s-1 under ambient conditions.
- Dhondge, Attrimuni P.,Huang, Yi-Xiang,Lin, Ta,Hsu, Yu-Hung,Tseng, Shin-Lun,Chang, Yu-Chang,Chen, Henry J. H.,Kuo, Ming-Yu
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Read Online
- Flexible side arms of ditopic linker as effective tools to boost proton conductivity of Ni8-pyrazolate metal-organic framework
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Two primitive metal-organic frameworks (MOFs), NiL1 and NiL2, based on Ni8O6-cluster and ditopic pyrazolate linkers, L1 (with rigid alkyne arms) and L2 (with flexible alkyne chains), were prepared. The proton conductivities of these MOFs in pristine form and imidazole-encapsulated forms, Im@NiL1 and Im@NiL2, were measured and compared. Upon introduction of imidazole molecules, the proton conductivity could be increased by 3 to 5 orders of magnitude and reached as high as 1.72 × 10?2 S/cm (at 98% RH and 80 °C). Also, whether imidazole molecules were introduced or not, Ni8O6-based MOFs with L2 in general gave better proton conductivity than those with L1 signifying that flexible side arms indeed assist proton conduction probably via establishment of efficient proton-conducting channels along with formation of highly ordered domains of water/imidazole molecules within the network cavities. Beyond the active Ni8O6-cluster, tuning flexibility of linker pendants serves as an alternative approach to regulate/modulate the proton conductivity of MOFs.
- Chung, Lai-Hon,Feng, Zihao,He, Jun,Hu, Jieying,Li, Jian-Rong,Liao, Wei-Ming,Luo, Qian-Ru,Wu, Can-Min,Zhang, Hu,Zhong, Yuan-Hui
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supporting information
(2022/01/11)
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- Green synthesis method for 2,5-dibromo-1,4-diiodobenzene intermediate
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The invention discloses a green synthesis method for a 2,5-dibromo-1,4-diiodobenzene intermediate, belonging to the technical field of intermediates of organic photoelectric materials. According to the method, organic cyclic high-valence iodine is used as an iodination reagent, metal organic phosphorus is used as a catalyst, trifluoromethanesulfonic acid is used as an additive, and 1,2-dichloroethane is used as a solvent; an ortho-position C-H bond is activated through a weak positioning group, namely a bromine group, and an ortho-position iodination reaction of p-dibromobenzene is experimented; and after the reaction is finished, the solvent is removed to directly obtain 2,5-dibromo-1,4-diiodobenzene. According to the method, the problems of poor iodination reaction purity and poor selectivity of traditional methods are solved, and high-purity, high-efficiency and high-selectivity iodination reaction of p-dibromobenzene is realized. By adopting the above optimized synthetic route, themethod has the advantages of greatly improved yield, reduced cost, enhanced safety, conservation of energy and the like, and meets the modern chemical production requirements on green reaction.
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Paragraph 0007
(2021/03/24)
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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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- The kinetics and mechanism of interconversion within a system of [Fe2L 3]4+helicates and [Fe4L 6]8+cages
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Nature builds simple molecules into highly complex assemblies, which are involved in all fundamental processes of life. Some of the most intriguing biological assemblies are those that can be precisely reconfigured to achieve different functions using the same building blocks. Understanding the reconfiguration of synthetic self-assembled systems will allow us to better understand the complexity of proteins and design useful artificial chemical systems. Here we have prepared a relatively simple system in which two distinct self-assembled structures, a [Fe2L3]4+ helicate and a [Fe4L6]8+ cage that are formed from the same precursors, coexist at equilibrium. We have measured the rates of interconversion of these two species and propose a mechanism for the transformation.
- Al-Fayaad, Hydar A.,Arachchige, Kasun S. A.,Brock, Aidan J.,Clegg, Jack K.,Luis, Ena T.,McMurtrie, John C.,Micallef, Aaron S.,Siddique, Rashid G.,Thoburn, John D.
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supporting information
p. 4918 - 4921
(2021/05/26)
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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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- Linker Deficiency, Aromatic Ring Fusion, and Electrocatalysis in a Porous Ni8-Pyrazolate Network
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The cruciform linker molecule here features two designer functions: the pyrazole donors for framework construction, and the vicinal alkynyl units for benzannulation to form nanographene units into the Ni8-pyrazolate scaffold. Unlike the full 12 connections of the Ni8(OH)4(H2O)2 clusters in other Ni8-pyrazolate networks, significant linker deficiency was observed here, leaving about half of the Ni(II) sites capped by acetate ligands, which can be potentially removed to open the metal sites for reactivity. The crystalline Ni8-pyrazolate scaffold also retains the crystalline order even after thermal treatments (up to 300 °C) that served to partially graphitize the neighboring alkyne units. The resultant nanographene components enhance the electroactive properties of the porous hosts, achieving hydrogen evolution reaction (HER) activity that rivals that of topical nickel/palladium-enabled materials.
- Hu, Jieying,Deng, Xiangling,Zhang, Hu,Diao, Yingxue,Cheng, Shengxian,Zheng, Sai-Li,Liao, Wei-Ming,He, Jun,Xu, Zhengtao
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supporting information
p. 161 - 166
(2021/01/11)
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- Dibenzoanthradiquinone Building Blocks for the Synthesis of Nitrogenated Polycyclic Aromatic Hydrocarbons
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A straightforward method for the synthesis of two dibenzo[a,h]anthracene-5,6,12,13-diquinone building blocks is reported. To showcase their usefulness, a series of dibenzo[a,h]anthracene nitrogenated derivatives have been synthesized that show different optoelectronic, redox, and charge transport properties, illustrating their potential as organic semiconductors.
- Martínez, Jose I.,Mora-Fuentes, Juan P.,Carini, Marco,Saeki, Akinori,Saeki, Akinori,Melle-Franco, Manuel,Mateo-Alonso, Aurelio,Mateo-Alonso, Aurelio
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supporting information
p. 4737 - 4741
(2020/06/29)
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- De Novo Design and Facile Synthesis of 2D Covalent Organic Frameworks: A Two-in-One Strategy
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We herein develop a two-in-one molecular design strategy for facile synthesis of 2D imine based covalent organic frameworks (COFs). The integration of two different functional groups (i.e., formyl and amino groups) in one simple pyrene molecule affords a bifunctional building block: 1,6-bis(4-formylphenyl)-3,8-bis(4-aminophenyl)pyrene (BFBAPy). Highly crystalline and porous Py-COFs can be easily prepared by the self-condensation of BFBAPy in various solvents, such as CH2Cl2, CHCl3, tetrahydrofuran, methanol, ethanol, acetonitrile, and dimethylacetamide, etc. The current work, to the best of our knowledge, is a rare case of COF synthesis that exhibits excellent solvent adaptability. Highly crystalline Py-COF thin films have been facilely fabricated on various substrates and exhibit potential applications in hole transporting layers for perovskite solar cells. Furthermore, the versatility of this two-in-one strategy was also verified by two additional examples. The current work dramatically reduces the difficulty of COF synthesis, and such two-in-one strategy is anticipated to be applicable for the synthesis of other COFs constructed by different building blocks and linkages.
- Li, Yusen,Chen, Qing,Xu, Tiantian,Xie, Zhen,Liu, Jingjuan,Yu, Xiang,Ma, Shengqian,Qin, Tianshi,Chen, Long
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supporting information
p. 13822 - 13828
(2019/09/30)
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- Method for synthesizing dibromobenzene -2,5- 1,4- diiodo benzene (by machine translation)
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The synthetic method disclosed by the invention comprises 1,4 - the following steps: the, synthesis method disclosed by. the, invention has a good industrial production prospect, 1,4 - in the prior, art that, the raw materials are firstly, 2,5 - subjected to a nitrification step and then subjected to 2,5 - an iodine, generation step to generate 2,5 - the second bromo,4-diiodo benzene 1,4 . (by machine translation)
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- Organic small molecular semiconductor material containing anthracene dithiophene as well as preparation method and application thereof
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The invention discloses an organic small molecular semiconductor material containing anthracene dithiophene as well as a preparation method and an application thereof. The structural formula of the material is as shown in a formula I, wherein the unit A is an electron deficient group; R1 is hydrogen or alkyl with 1-30 carbon atoms or a group in the alkyl with 1-30 carbon atoms, one or more of which are replaced by halogen atoms, oxygen atoms, alkenyl, alkynyl, aryl, hydroxyl, amino, carboxyl, ester groups, cyan or nitryl. The material has unique advantages of relatively good light capturing ability, proper electronic energy level, relatively high electronic mobility and the like, and is applied to organic solar battery apparatuses as an electron acceptor material to obtain good apparatus performances.
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Paragraph 0028; 0029; 0030
(2018/06/16)
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- Benzene and naphtho-silole derivative organic photoelectric material and preparation method thereof
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The invention discloses a benzene and naphtho-silole derivative organic photoelectric material and a preparation method thereof. The preparation method mainly comprises the steps that 1,4-dibromo-2,5-diiodobenzene, a naphthalene derivative, an alkynyl naphthalene derivative, a silicon naphthalene derivative and a silicon-bridged diyne derivative are sequentially prepared; and a finally prepared benzene and naphtho-silole derivative is the organic photoelectric material. Cyclopentadiene zirconacycles is synthesized through the lithiation effect of n-butyllithium; a naphthalene substitute is synthesized through the catalytic effect of CuCl; a silicon substitute is synthesized through the catalytic effect of PdCl2(PPh3)2 and the lithiation effect of n-butyllithium; silicon-bridged diyne is synthesized through the lithiation effect of n-butyllithium; and the benzene and naphtho-silole derivative is synthesized through the catalytic effect of CuCl. The synthesization process is mild in condition, short in reaction time and low in energy consumption, the raw materials are easy to obtain, and finally, the benzene and naphtho-silole derivative is obtained with the high yield in short reaction time.
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Paragraph 0023; 0024; 0036; 0043
(2017/08/28)
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- NON-FULLERENE ELECTRON ACCEPTORS
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The invention provides electron acceptor compound of Formula (I) which may be used in organic compositions for optical or electronic devices.
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Page/Page column 31
(2017/12/13)
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- BENZODIFURAN DERIVATIVE AND ORGANIC THIN FILM TRANSISTOR
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PROBLEM TO BE SOLVED: To provide a novel benzodifuran derivative as a coating type organic semiconductor material having high carrier mobility, high heat resistance and high solubility, and an organic semiconductor layer using the same. SOLUTION: The benzodifuran derivative is represented by the general formula (1) in the figure. (In the formula, substituents R1 and R2 are identical or different and represent hydrogen, bromine, iodine, C1-12 alkyl, C4-14 aryl, C2-14 alkynyl or C2-14 alkenyl; and T1 and T2 are identical or different and represent sulfur or oxygen.) COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0109; 0110
(2016/10/09)
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- Palladium-catalyzed domino C-H/N-H functionalization: An efficient approach to nitrogen-bridged heteroacenes
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Palladium-catalyzed domino C-H/N-H functionalization for the synthesis of novel nitrogen-bridged thienoacenes and 10H-benzo[4,5]thieno[3,2-b]indole derivatives from dihaloarene is reported. This domino sequence consists of initial C-H functionalization of the benzo[b]thiophene moiety, followed by Buchwald-Hartwig coupling. This transformation is also useful for the synthesis of highly π-extended compounds. Extended heteroacenes: A twofold arylation protocol for the efficient synthesis of 9H-benzo[4,5]thieno[3,2-b]thieno[3,4-d]pyrroles and 10H-benzo[4,5]thieno[3,2-b]indoles was developed (see scheme). The selectivity of this novel sequence allows the construction of highly π-extended heteroacenes.
- Kamimoto, Natsuyo,Schollmeyer, Dieter,Mitsudo, Koichi,Suga, Seiji,Waldvogel, Siegfried R.
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supporting information
p. 8257 - 8261
(2015/05/27)
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- Fluoride binding to an organoboron wire controls photoinduced electron transfer
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We demonstrate that the rates for long-range electron transfer can be controlled actively by tight anion binding to a rigid rod-like molecular bridge. Electron transfer from a triarylamine donor to a photoexcited Ru(bpy)32+ acceptor (bpy = 2,2′-bipyridine) across a 2,5-diboryl-1,4-phenylene bridge occurs within less than 10 ns in CH2Cl2 at 22 °C. Fluoride anions bind with high affinity to the organoboron bridge due to strong Lewis base/Lewis acid interactions, and this alters the electronic structure of the bridge drastically. Consequently, a large tunneling barrier is imposed on photoinduced electron transfer from the triarylamine to the Ru(bpy)32+ complex and hence this process occurs more than two orders of magnitude more slowly, despite the fact that its driving force is essentially unaffected by fluoride addition. Electron transfer rates in proteins could potentially be regulated via a similar fundamental principle, because interactions between charged amino acid side chains and counter-ions can modulate electronic couplings between distant redox partners. In artificial donor-bridge-acceptor compounds, external stimuli have been employed frequently to control electron transfer rates, but the approach of exploiting strong Lewis acid/Lewis base interactions to regulate the tunneling barrier height imposed by a rigid rod-like molecular bridge is conceptually novel and broadly applicable, because it is largely independent of the donor and the acceptor, and because the effect is not based on a change of the driving-force for electron transfer. The principle demonstrated here can potentially be used to switch between conducting and insulating states of molecular wires between electrodes. This journal is
- Chen, Jing,Wenger, Oliver S.
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p. 3582 - 3592
(2015/05/27)
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- GRAPHENE NANORIBBONS, METHODS OF MAKING SAME, AND USES THEREOF
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Provided are graphene nanoribbons (GNRs), methods of making GNRs, and uses of the GNRs. The methods can provide control over GNR parameters such as, for example, length, width, and edge composition (e.g., edge functional groups). The methods are based on a metal catalyzed cycloaddition reaction at the carbon-carbon triple bonds of a poly(phenylene ethynylene) polymer. The GNRs can be used in devices such a microelectronic devices.
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Paragraph 0067; 0068
(2014/08/07)
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- Electron-rich pyrroloindacenodithiophenes: Synthesis, characterization, and spectroscopic studies
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N-Alkyl substituted pyrroloindacenodithiophene (PIDT) and their phenyl substituted derivatives were synthesized. Their single-crystal structures and electrochemical and spectroscopic properties were investigated. Experimental results showed PIDT displayed strong electron-donating properties, reversible redox behaviors, and strong fluorescence and could be controlled to oxidize to radical cation and dication with distinctive optical changes. These attractive properties demonstrated the potential applications of PIDT in the field of switches, molecular machines, and information memories.
- Xiong, Yu,Wu, Qinghe,Li, Jie,Wang, Shitao,Gao, Xike,Li, Hongxiang
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supporting information
p. 752 - 756
(2013/02/26)
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- Synthesis and characterization of a low-bandgap poly(arylene ethynylene) having donor-acceptor type chromophores in the side chain
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A low-bandgap poly(arylene ethynylene) (PAE) having donor-acceptor type chromophores in the side chain was synthesized. A π-conjugated PAE precursor having electron-rich dioctylanilino-substituted alkynes in the side chain was polymerized through Sonogashira cross-coupling reaction between functional monomers M-I with terminal acetylenes and M-II with diiodide, using tetrakis(tripheneylphosphine)palladium and copper iodide catalysts in a mixed solvent of triethylamine and tetrahydrofuran (THF) at 50°C. The electronically rich N,N-dioctylamino groups in M-I activated the alkynes in the side chains of M-I, thus making the selective reaction of sidechain alkynes with TCNE possible in the post-functionalization step. The selective reaction of TCNE (tetracyanoethylene) with activated dioctylanilino substituted alkynes in the side chains of precursor polymer afforded the target poly(arylene ethynylene). This unique polymer shows enhanced thermal stability and exhibits strong intramolecular charge-transfer interactions, resulting in a very low bandgap of poly(arylene ethynylene).
- Huang, Wenyi,Chen, Hongyan
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p. 2032 - 2037
(2013/04/24)
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- Highly efficient benzannulation of poly(phenylene ethynylene)s
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Put a ring on it: Sterically congested polyarylenes can be synthesized by benzannulation reactions at each C≡C bond of a poly(phenylene ethynylene) (see picture), one of the most easily synthesized and versatile classes of conjugated polymers. The benzannulation reaction is highly specific and efficient, as determined by an isotopic labeling study and several complementary spectroscopic methods. Copyright
- Arslan, Hasan,Saathoff, Jonathan D.,Bunck, David N.,Clancy, Paulette,Dichtel, William R.
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supporting information
p. 12051 - 12054
(2013/01/16)
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- Influence of bromine substitution pattern on the singlet oxygen generation efficiency of two-photon absorbing chromophores
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A molecular engineering strategy based on rational variations of the bromine substitution pattern in two-photon absorbing singlet oxygen sensitizers allows studying the relations that exist between the positioning of an inter-system crossing promoter on the charge-transfer chromophore and its ability to generate singlet oxygen. The Royal Society of Chemistry 2012.
- Lano?, Pierre-Henri,Gallavardin, Thibault,Dupin, Aurore,Maury, Olivier,Baldeck, Patrice L.,Lindgren, Mikael,Monnereau, Cyrille,Andraud, Chantal
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supporting information; experimental part
p. 6275 - 6278
(2012/09/05)
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- Tetrathienoanthracene-based copolymers for efficient solar cells
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A series of semiconducting copolymers (PTAT-x) containing extended π-conjugated tetrathienoanthracene units have been synthesized. It was shown that the extended conjugation system enhanced the π-π stacking in the polymer/PC61BM blend films and facilitated the charge transport in heterojunction solar cell devices. After structural fine-tuning, the polymer with bulky 2-butyloctyl side chains (PTAT-3) exhibited a PCE of 5.6% when it was blended with PC61BM.
- He, Feng,Wang, Wei,Chen, Wei,Xu, Tao,Darling, Seth B.,Strzalka, Joseph,Liu, Yun,Yu, Luping
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supporting information; experimental part
p. 3284 - 3287
(2011/05/03)
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- Bifunctional cross-conjugated luminescent phosphines and phosphine derivatives: Phospha-cruciforms
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Cross-conjugated bifunctional species including a phosphine, phosphine oxide, phosphine sulfide, phosphonium salt, phosphorus ylide and a gold(i) phosphine complex have been prepared. The photophysical characteristics of the series of compounds have been determined experimentally and are discussed/compared with simpler analogues lacking cross-conjugated branches and rationalized on the basis of DFT calculations. The Royal Society of Chemistry 2010.
- Mangalum, Anshuman,Smith, Rhett C.
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scheme or table
p. 5145 - 5151
(2010/07/09)
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- A versatile preparation of gelaender-type p-terphenyls from a readily available diacetylenic precursor
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A series of doubly bridged p-terphenyls (4) have been synthesized utilizing a facile three-step synthesis starting from the readily available dlacetylenlc precursor (1) In excellent overall yields, and their structures were confirmed by 1H/13 NMR spectroscopy as well as by X-ray crystallography. The racemization barrier between the meso and chlral atropisomers of one of the derivatives of 4 was found to be ~12 kcal/mol by variable-temperature NMR spectroscopy. The versatility of the protocol developed herein was further demonstrated by the preparation of a quadruply bridged penta-p-phenylene derivative.
- Modjewski, Matthew,Lindeman, Sergey V.,Rathore, Rajendra
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supporting information; experimental part
p. 4656 - 4659
(2009/12/26)
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- HETEROACENE DERIVATIVE, TETRAHALOTERPHENYL DERIVATIVE, AND THEIR PRODUCTION METHODS
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There are provided a heteroacene derivative having an excellent oxidation resistance and capable of forming a semiconductor active phase by a coating process, and an oxidation-resistant organic semiconductor material using the same, as well as an organic thin film. [Means for Resolution] heteroacene derivative represented by the formula (1) is obtained by tetrametalation of a tetrahaloterphenyl derivative with a metalation agent and subsequent treatment of the resulting compound with reaction agents: wherein the substituents R1 to R4 are the same or different and each represents a hydrogen atom, a fluorine atom, a chlorine atom, an aryl group having 4 to 30 carbon atoms, an alkyl group having 3 to 20 carbon atoms, or a halogenated alkyl group having 1 to 20 carbon atoms; T1 and T2 are the same or different and each represents sulfur, selenium, tellurium, oxygen, phosphorus, boron, or aluminum; 1 and m each is an integer of 0 or 1; and rings A and B are the same or different and each has a structure represented by the following formulae (A-1) or (A-2).
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Page/Page column 23
(2019/07/30)
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- Conformation as a protecting group: A regioselective aromatic bromination en route to complex π-electron systems
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(Chemical Equation Presented) A new strategy to achieve regioselective functionalization of a sterically congested aromatic system driven by conformational demands is described. Electrophilic substitution occurs at the more planarizable subunit without undesired chemistry at mutually reactive sites and without the need for protecting or masking groups that must be manipulated later. Model studies are described to understand this selectivity, and possibilities for the construction of orthogonal, differentially substituted π-systems of relevance for molecular electronics are demonstrated.
- Guthrie, Daryl A.,Tovar, John D.
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supporting information; body text
p. 4323 - 4326
(2009/06/06)
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- TERPHENYLENE DERIVATIVES, TETRAHALOTERPHENYL DERIVATIVES AND PROCESSES FOR THE PRODUCTION OF BOTH
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The invention provides terphenylene derivatives which have excellent oxidation resistance and permit the formation of semiconductor active phases by coating; and oxidation-resistant organic semiconductor materials and organic thin films, made by using the same. The invention relates to production of terphenylene derivatives represented by the general formula (1) by tetralithiating a tetrahaloterphenyl derivative with a lithiating agent and then treating the obtained compound with a copper compound: (1) wherein R1 to R14 are each independently hydrogen, fluoro, chloro, aryl having 4 to 30 carbon atoms, alkynyl having 3 to 20 carbon atoms, alkenyl having 2 to 30 carbon atoms, alkyl having 1 to 20 carbon atoms, halogenated alkyl having 1 to 20 carbon atoms, or diarylamino having 8 to 30 carbon atoms; and l, m, and n are each an integer of 0 or 1.
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Page/Page column 47-48
(2008/06/13)
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- Linear C2-symmetric polycyclic benzodithiophene: Efficient, highly diversified approaches and the optical properties
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Two facile approaches to two new series of the seven-rings fused benzodithiophene-based polycyclic aromatics are developed in good yields.
- Wang, Cui-Hua,Hu, Rong-Rong,Liang, Shuang,Chen, Jia-Hua,Yang, Zhen,Pei, Jian
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p. 8153 - 8157
(2007/10/03)
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- Synthesis of Anthropomorphic Molecules: The NanoPutians
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Described here are the synthetic details en route to an array of 2-nm-tall anthropomorphic molecules in monomeric, dimeric, and polymeric form. These anthropomorphic figures are called, as a class, NanoPutians. Using tools of chemical synthesis, the ultimate in designed miniaturization can be attained while preparing the most widely recognized structures: those that resemble humans.
- Chanteau, Stephanie H.,Tour, James M.
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p. 8750 - 8766
(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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- 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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- 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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