- Facile Synthesis of a Fully Fused, Three-Dimensional ?-Conjugated Archimedean Cage with Magnetically Shielded Cavity
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The synthesis of molecular cages consisting of fully fused, ?-conjugated rings is rare due to synthetic challenges including preorganization, large strain, and poor solubility. Herein, we report such an example in which a tris-2-aminobenzophenone precursor undergoes acid-mediated self-condensation to form a truncated tetrahedron, one of the 13 Archimedean solids. Formation of eight-membered [1,5]diazocine rings provides preorganization and releases the strain while still maintains weak ?-conjugation of the backbone. Thorough characterizations were performed by X-ray, NMR, and UV-vis analysis, assisted by theoretical calculations. The cage exhibits a rigid backbone structure with a well-defined cavity that confines a magnetically shielded environment. The solvent molecule, o-dichlorobenzene, is precisely encapsulated in the cavity at a 1:1 ratio with multiple ?···?, C-H···?, and halogen···πinteractions with the cage skeleton, implying its template effect for the cage closing reaction. Our synthetic strategy opens the opportunity to access more complex, fully fused, three-dimensional ?-conjugated cages.
- Han, Yi,Jiao, Tianyu,Li, Zhengtao,Ni, Yong,Wu, Jishan,Wu, Shaofei,Zhang, Qiuyu,Zhu, Jun
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p. 14314 - 14321
(2021/09/13)
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- Synthesis method of 2-bromoheptafluoronaphthalene compound
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The invention relates to a synthesis method of 2-bromoheptafluoronaphthalene compound. The synthesis method includes the steps of: 1) a fluorination reaction; 2) a hydrazine substitution reaction; and3) a bromination reaction. With octachloronaphthalene as a raw material, the 2-bromoheptafluoronaphthalene is prepared through reactions of fluorination, hydrazine substitution and bromination. The method is low in cost, has simple reaction steps and low toxicity, is convenient to carry out and high in yield, and is suitable for industrial production.
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Paragraph 0012
(2018/06/26)
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- Catalytic C-F bond activation of geminal difluorocyclopropanes by nickel(i) complexes via a radical mechanism
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Nickel(ii) fluorido complexes bearing NNN-pincer ligands were found to be catalysts in the hydrodefluorination of geminal difluorocyclopropanes which undergo ring-opening to form the corresponding monofluoroalkenes in good yield and high Z-selectivities. Evidence for a radical based mechanism involving nickel(i) and nickel hydrido complexes as key intermediates was obtained in the corresponding stoichiometric reactions.
- Wenz, Jan,Rettenmeier, Christoph A.,Wadepohl, Hubert,Gade, Lutz H.
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supporting information
p. 202 - 205
(2015/12/26)
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- Fluoroalkane aromatization over hot sodium oxalate
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Hot sodium oxalate (465°C) aromatizes perfluorodecalin to give perfluorotetralin and perfluoronaphthalene. Decomposition of solid sodium oxalate at temperatures above 450°C involves initial formation of elemental carbon that catalyzes the subsequent decomposition of oxalate, leading to the presence of an induction period in the overall decomposition reaction. Prior incipient decomposition of sodium oxalate to carbon and sodium carbonate is necessary for this reagent to effect aromatization.
- McAlexander, Lenore Hoyt,Beck, Christopher M.,Burdeniuc, Juan J.,Crabtree, Robert H.
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- Recent advances in C-F bond activation
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The main reaction pathways which lead to the breaking of C-F bonds in perfluoroalkanes and -arenes are discussed. Emphasis is placed on recent developments and on the mechanistic patterns that emerge. VCH Verlagsgesellschaft mbH.
- Burdeniuc, Juan,Jedlicka, Brigitte,Crabtree, Robert H.
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p. 145 - 154
(2007/10/03)
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- Mobilities of Radical Cations and Anions, Dimer Radical Anions, and Relative Electron Affinities by Times of Flight in n-Hexane
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The mobilities of several radical cations and anions are measured in n-hexane using a thin-sheet time-of-flight (TOF) technique.We observe the radical cations of N,N,N',N'-tetramethyl-p-phenylenediamine, zinc tetraphenylporphine, and pyrene and the radical anions of perfluorobenzene, p-benzoquinone, anthraquinone, chloranil, buckminsterfullerene (C60), and octafluoronaphthalene.For all electron acceptors but C60, the dependence of the anionic TOF on acceptor concentration reveals the appearance of the homodimer radical anion at sufficiently high concentrations.The equilibrium constant for the monomer anion/monomer acceptor association reaction is obtained from the concentration studies.A Born-Haber cycle is then applied to estimate the difference between the electron affinities of the monomer and dimer molecules in the gas phase.
- Lim, S. K.,Burba, M. E.,Albrecht, A. C.
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p. 9665 - 9675
(2007/10/02)
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- Selective Reduction of Saturated Perfluorocarbons
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Perfluorocycloaliphatic compounds are reduced by solutions of the sodium benzophenone radical anion to give perfluorinated and highly fluorinated aromatic compounds.Perfluorocycloalkanes containing tertiary carbon centers are much more reactive than perfluorocyclohexane.Reduction of perfluoroalkanes and perfluorocycloalkanes that contain perfluoroalkyl substituents proceeds easily; however, it appears that overreduction occurs and no organofluorine products are obtained with these substrates.The selectivity and reactivity of several radical anion reducing agents are strongly correlated with the electrochemical behavior of the reducing agents, the perfluoroalkanes, and the observed perfluoroaromatic reduction products.Direct electrochemical reduction of saturated unsubstituted perfluoroalkanes on an analytical scale was observed for the first time in this work.
- Marsella,John A.,Gilicinski, Andrew G.,Coughlin, Anne M.,Pez, Guido P.
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p. 2856 - 2860
(2007/10/02)
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- Synthesis of highly fluorinated aromatic compounds
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A process is disclosed for making a highly fluorinated aromatic compound by contacting a perfluorocycloalkane, such as perfluorodecahydronaphthalene, with a complex of a metal from Groups IA and IIA of the Periodic Table and an organic electron acceptor. The reaction is carried out in an organic solvent and under reducing conditions which are relatively moderate. Best results are obtained using a perfluorocycloalkane having 2-4 condensed rings and a complex of either sodium or lithium and benzophenone thereby making a perfluorinated condensed ring aromatic compound such as perfluoronaphthalene or perfluorophenanthrene.
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- DEFLUORINATION OF HEXADECAFLUOROBICYCLODEC-1-ENE: A FACILE SYNTHESIS OF PERFLUOROAROMATICS
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Depending mainly on the polarity of the aprotic solvent used, defluorination of hexadecafluorobicyclodec-1(6)-ene (1) with activated zinc gave tetradecafluorobicyclodec-1(2),6(7)-diene (2), perfluorotetraline (3), decafluoro-1,2-dihydronaphthalene (4) and perfluoronaphthalene (5).In methanol, 2,7-dimethoxy-dodecafluorobicyclodec-1(2),6(7)-diene (6) was formed.These products were characterized by elemental analysis, IR, UV, 1H NMR and 19F NMR.An electron transfer and then a radical intermediate seem to be involved in such defluorination reactions.
- Hu, Chang-Ming,Long, Fei,Xu, Ze-Qi
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- The Preparation and Characterization of Radical Cation Salts Derived from Perfluorobenzene, Perfluorotoluene, and Perfluoronaphthalene
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The salts C6F6+AsF6- (yellow), C6F5CF3- (lime green), and C10F8+AsF6- (dark green) may be prepared by electron oxidation of the appropriate perfluoro aromatic molecule with O2+AsF6-.Other O2+ salts can be similarly employed as can the more strongly oxidizing transition-metal hexafluorides, but salts of the latter are more labile than their AsF- relatives.C6F6+AsF6- is a convenient electron oxidizer (C6F6AsF6+C10F8 -> C10F8AsF6+C6F6) since that which remains from the reaction decomposes at room temperature to volatile products (2C6F6AsF6 -> C6F6+1,4-C6F8+2AsF5).Magnetic susceptibilities for C6F6AsF6 and C10F8AsF6 approximate to Curie law behavior, and g values are close to free-electron values.X-ray diffraction data (single crystal) show C6F6AsF6 to be primitive rhombohedral with a0=6.60 (1) Angstroem, α=106.0 (1) deg, V=246.1 Angstreom3, Z=1, probable space group R3, and (powder data) C10F8AsF6 to be tetragonal with a0=8.27 (5) Angstroem, c0=18.57 (s) Angstroem, V=1270 Angstoem3, Z=4.Salts derived from the monocyclic perfluoro aromatics are thermally unstable but can be kept below -15 deg C.The perfluoronapthalene salts are indefinitely stable at room temperatures.All hydrolyze rapidly.The products of thermal decomposition of the hexafluoroarsenates of the monocyclic cation salts parallel the products of the attack by F-.The latter reaction products are in the molar ratios indicated by the following equations: 2C6F6+ 2F- -> C6F6+ 1,4-C6F8; 2C6F5CF3+ ->2F- -> C6F5CF3+1,3-C6F7CF3.The 1,3-C6F7CF3 isomerizes to a 1:1 mixture with 1,4-C6F7CF3 over several days in the presence of fluoro acids.Mechanisms for the formation of the dienes are discussed.
- Richardson, T. J.,Tanzella, F. L.,Bartlett, Neil
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p. 4937 - 4943
(2007/10/02)
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- THERMOLYTIC REACTIONS OF POLYFLUOROORGANIC COMPOUNDS, PART XXVII. INTERACTION OF 1,1-DICHLOROPOLYFLUOROINDANES WITH HALOFORMS
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A number of polyfluoro-1-methyleneindanes have been obtained by copyrolysis of 1,1-dichloropolyfluoroindanes with CF2=CF2, CHClF2, CHCl2F, CHCl3.A possibility is shown for the reaction of 1,1-dichloroctafluoroindan with CHClF2 to proceed by way of difluorocarbene insertion into the C - Cl bond of the benzylic position of this indan, with subsequent dechlorination of the insertion product.
- Karpov, V. M.,Platonov, V. E.,Chuikov, I. P.,Yakobson, G. G.
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p. 459 - 474
(2007/10/02)
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