- Preparation of monofluorophenols via the reaction of difluorobenzene derivatives with potassium trimethylsilanoate
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An efficient synthesis of monofluorophenols via the reaction of difluorobenzene derivatives with potassium trimethylsilanoate in moderate to excellent yields is described. High regioselectivity was observed in some cases. Georg Thieme Verlag Stuttgart.
- Li, Jianqing,Smith, Daniel,Qiao, Jennifer X.,Huang, Stella,Krishnananthan, Subramaniam,Wong, Henry S.,Salvati, Mark E.,Balasubramanian, Balu N.,Chen, Bang-Chi
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scheme or table
p. 633 - 637
(2009/07/01)
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- Synthesis of fluorosubstituted three ring esters and their dielectric properties
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Laterally substituted by fluorine atoms 4-cyanophenyl 4-(4- pentylbenzoyloxy)-benzoates have been prepared and their phase transition temperatures, enthalpies and dielectric properties upon frequency were evaluated. The novel compounds exhibit a broad range of nematic mesophase, large positive dielectric anisotropy changing sign at low frequency. They are convenient components of LC mixtures for dual frequency addressing devices. Copyright Taylor & Francis Group, LLC.
- Ziobro, Dorota,Dziaduszek, Jerzy,Filipowicz, Marek,Dabrowski, Roman,Czu, Joanna,Urban, Stanislaw
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p. 258 - 271
(2012/08/08)
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- Influence of fluoro substituents on the mesophase behaviour of banana-shaped molecules
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Three new series of bent-shaped five-ring liquid crystals, based on the ester of isophthalic acid as the central core and azomethine linkages, are presented. They differ by the number and the position of halogeno substituents on the outer rings. This lateral substitution strongly influences the type of mesophases formed. Calculations were performed to determine the modification of the distribution of charge along the different molecules.
- Bedel,Rouillon,Marcerou,Laguerre,Nguyen,Achard
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p. 2214 - 2220
(2007/10/03)
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- Elemental fluorine Part 12. Fluorination of 1,4-disubstituted aromatic compounds
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Direct fluorination of a series of 1,4-disubstituted benzene derivatives in acid reaction media at convenient temperature leads, in many cases, to selectively fluorinated aromatic products in preparatively useful conversions and yields.
- Chambers, Richard D.,Hutchinson, John,Sparrowhawk, Matthew E.,Sandford, Graham,Moilliet, John S.,Thomson, Julie
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p. 169 - 173
(2007/10/03)
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- Synthesis of 3-deoxy-3,3-difluoroshikimic acid and its 4-epimer from quinic acid
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3-Deoxy-3,3-difluoroshikimic acid 2 and its 4-epimer 3 as new analogues of shikimic acid have been synthesised from quinic acid in overall yields of 30% and 12%, respectively.
- Jiang, Shende,Singh, Gurdial,Boam, Deborah J.,Coggins, John R.
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p. 4087 - 4090
(2007/10/03)
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- Liquid crystal materials, mixtures and devices
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Liquid crystal compounds of formula I may be used by themselves or they may be mixed with other liquid crystal compounds to give useful liquid crystal mixtures which may then be used in liquid crystal devices. The materials exhibit smectic mesophases and may therefore be used in ferroelectric, ferrielectric, antiferroelectric, themochromic and electroclinic devices. They may also be used as long pitch materials.
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- The Synthesis and Liquid Crystal Properties of Some Laterally Fluorinated trans-Cyclohexane-1-carboxylate and Benzoate Esters
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A large number of laterally fluorinated 4-n-alkyl- and -alkoxy-phenyl 4'-n-alkyl- and -alkoxy-bezoates and 4-n-alkylphenyl trans-4'-n-alkyl- and -alkoxy-cyclohexane-1-carboxylates were synthesised.In these compounds, the lateral fluoro-substituent was situated in either the phenol or the carboxylic acid moiety of the molecules for the benzoate esters, but only in the phenol moiety for the trans-cyclohexane-1-carboxylate esters.The nematic thermal stabilities for the fluorophenyl bezoate and trans-cyclohexane-1-carboxylate esters and the fluorobenzoate esters were compared with those for the corresponding non-fluorinated analogues.A nematic thermal efficiency order was derived for the 4-n-alkyl-fluorophenyl 4-n-alkylbezoate and trans-4-n-alkylcyclohexane-1-carboxylate esters, but only in the case of the latter esters, which were extensively examined, was the smectic tendency of the system investigated.Explanations are given for the observed nematic and smectic thermal stabilities of the titled esters, and some of their physical properties are discussed.
- Gray, G. W.,Hogg, C.,Lacey, D.
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