- Nematic stability of 2,2′,4-trifluoro-4″-alkyl-[1,1′:4′,1″]terphenyls and its deuterated isotopologue
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In this work we present three synthetic methodologies of 2,2′,4-trifluoro-4″-alkyl-[1,1′:4′,1″]terphenyls. The most convenient synthetic method was used for homologous series of 2,2′,4-trifluoro-4″-alkyl-[1,1′:4′,1″]terphenyls (alkyl chain from methyl to hexyl). The results show that fluorination in the inner-core position (at 2 and 2′ position of terphenyl core) promotes only a nematic phase. The results have also been discussed with other chloro- and fluoro- substituted 4″-alkyl-[1,1′:4′,1″]terphenyls and one perdeuterated terphenyl analogue. The synthesis and purity of synthesized compounds were monitored by gas chromatography GC-MS, GC-FID and by thin layer chromatography (TLC). The phase situation and the phase transition temperatures were determined by polarized optical microscopy (POM). The temperatures and enthalpies of the phase transitions were measured by using differential scanning calorimetry (DSC).
- Pytlarczyk, Marta,Gaczo?, Kornelia,Harmata, Piotr,Dziaduszek, Jerzy,Herman, Jakub
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- A normal-temperature process for preparing 2, 4 - difluorobenzene boric acid (by machine translation)
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The invention relates to the field of organic synthesis, discloses a preparation at room temperature 2, 4 - difluorobenzene boric acid, the method in order to 2, 4 - difluoro, splicing, boric acid ester as the raw material, the auxiliary ether solvent, by instantaneous control reaction of 2, 4 - difluoro bromobenzene concentration, so that the 2, 4 - difluoro phenyl [...] concentration is kept at a relatively low level, then the use of ultrasonic radiation to speed up the 2, 4 - difluoro phenyl [...] into 2, 4 - difluorobenzene boronic acid, greatly reduces the by-product, and use the extraction - re-extracted technology to remove by-product, the highest yield of 70%, purity 95 - 99%. The raw materials used in this invention is cheap and easy to obtain, mild reaction conditions, the process is simple and safe, low production cost, the resulting high product yield, purity is good, it has important industrialization prospect. (by machine translation)
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Paragraph 0017-0024
(2018/04/01)
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- ORGANIC METAL COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE EMPLOYING THE SAME
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Organic metal compounds and organic electroluminescence devices employing the same are provided. The organic metal compound has a chemical structure represented below: wherein R1, R2, R3, R4, and R5 are independent and can be hydrogen, halogen, C1-8 alkyl or C1-8alkoxy; L can be acetylacetone ligand, picolinic acid ligand, N,N′-diisopropylbenzamidinate, or N,N′-diisopropyl-diisopropyl-guanidinate.
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- Synthetic method of organometallic iridium compound
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A synthetic method for preparing organometallic iridium compounds is provided and includes the two steps of (1) synthesizing a di-iridium compound with a halogenated bridge: L2Ir(μ?X)2IrL2, L; and (2) reacting L2Ir(μ?X)2IrL2 with a ligand to give the product [C?]N]2Ir (LX). The invention is an improvement over the traditional method for preparing such compounds and has the advantages of shortened reaction time, increased yield, and products of over 99% purity obtained without chromatography.
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Page/Page column 2-3
(2012/12/14)
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- Substituent effects on aryltrifluoroborate solvolysis in water: Implications for Suzuki-Miyaura coupling and the design of stable 18F-labeled aryltrifluoroborates for use in PET imaging
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(Chemical Equation Presented) Whereas electron withdrawing substituents retard the rate of aryltrifluoroborate solvolysis, electron-donating groups enhance it. Herein is presented a Hammett analysis of the solvolytic lability of aryltrifluoroborates where log(Ksolv) values correlate to a values with a ρ value of approximately -1. This work provides a predictable rubric for tuning the reactivity of boron for several uses including 18F-labeled PET reagents and has mechanistic implications for ArBF3-enhanced ligandless metal-mediated cross coupling reactions with aryltrifluoroborates.
- Ting, Richard,Harwig, Curtis W.,Lo, Justin,Li, Ying,Adam, Michael J.,Ruth, Thomas J.,Petrin, David M.
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p. 4662 - 4670
(2008/09/20)
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- Polyfluoroorganoboron-oxygen compounds. 1: Polyfluorinated aryl(dihydroxy)boranes and tri(aryl)boroxins
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A general preparative procedure for polyfluorinated aryl(dihydroxy)boranes C6H5-nFnB(OH)2 (n = 3 - 5) is described. Polyfluorinated aryl(dihydroxy)boranes are easily dehydrated to the corresponding tri(aryl)boroxins (C6H5-nFnBO)3 by thermal or chemical treatment. The property of the acids C6H5-nFnB(OH)2 to condensate depends on the number and on the position of the fluorine atoms in the aryl group. Examples of both classes of boron compounds were isolated as pure individuals and characterized by multinuclear NMR spectroscopy.
- Frohn,Adonin,Bardin,Starichenko
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p. 2827 - 2833
(2008/10/08)
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- Process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid
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A process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid comprising the reaction of an organometallic derivative with a suitable substituted benzene in the presence of a transition-metal based catalyst is described.
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- Process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid
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A process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid comprising the reaction of an organometallic derivative with a suitable substituted benzene in the presence of a transition-metal based catalyst is described.
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