- Ferro-, ferri- and antiferro-electric behaviour in a bent-shaped mesogen
-
The synthesis of a novel bent-shaped, four-ring thiophene-based chiral liquid crystalline ester derived from 5-(4-n-decyloxyphenyl)thiophene-2- carboxylic acid and (S)-1-methylheptyl 4'-hydroxybiphenyl-4-carboxylate is reported, i.e., (S)-4'-(1-methylheptyloxycarbonyl)biphenyl-4-yl 5-(4-n- decyloxyphenyl)thiophene-2-carboxylate. Optical microscopy, differential scanning calorimetry, miscibility study, and complementary electro-optical and current response studies reveal the existence of the SmA*, SmC* ferroelectric, SmC* ferrielectric, SmC* antiferroelectric and SmI* antiferroelectric phase types. Another mesophase type possibly exists below SmI* antiferroelectric which generates a rapid electro-optic response. Comparison with the analogous three-ring compound, i.e., (S)-4-(1- methylheptyloxycarbonyl)phenyl 5-(4-n-decyloxyphenyl)thiophene-2-carboxylate increases the thermal stability by 95.8 °C and the SmI* antiferroelectric phase is observed in addition.
- Matharu, Avtar S.,Grover, Chrissie,Komitov, Lachezar,Andersson, Gunnar
-
-
Read Online
- Azo bond formation on metal surfaces
-
The formation of azo compounds via redox cross-coupling of nitroarenes and arylamines, challenging in solution phase chemistry, is achieved by on-surface chemistry. Reaction products are analyzed with a cryogenic scanning tunneling microscope (STM) and X-ray photoelectron spectroscopy (XPS). By using well-designed precursors containing both an amino and a nitro functionality, azo polymers are prepared on surface via highly efficient nitro-amino cross-coupling. Experiments conducted on other substrates and surface orientations reveal that the metal surface has a significant effect on the reaction efficiency. The reaction was further found to proceed from partially oxidized/reduced precursors in dimerization reactions, shedding light on the mechanism that was studied by DFT calculations.
- Meng, Xiangzhi,Klaasen, Henning,Viergutz, Lena,Schulze Lammers, Bertram,Witteler, Melanie C.,M?nig, Harry,Amirjalayer, Saeed,Liu, Lacheng,Neugebauer, Johannes,Gao, Hong-Ying,Studer, Armido,Fuchs, Harald
-
supporting information
p. 1458 - 1464
(2020/12/14)
-
- New pyridine based liquid crystalline esters with different terminal chains
-
The synthesis, structural and mesomorphic characterization of new pyridine-based methyl esters carrying a n-alkoxy chain or 3,7-Dimethyloctyloxy branched group at terminal have been presented. The liquid crystalline properties of the new pyridine-based calamitic molecules have been investigated by polarized optical microscopy and differential scanning calorimetry. New compounds exhibit enantiotropic smectic A mesophase at a variable mesomorphic range depending on alkoxy chain length and branching at terminal. The presence of a branched terminal group in chiral or racemic form gives rise to a sharply increase in mesomorphic range as well as decrease in crystallization points by preserving mesophase type.
- Karanl?k, Gürkan,Ocak, Hale,Bilgin Eran, Belk?z
-
-
- Design and synthesis of a new family of fluorinated liquid crystals
-
A convenient and simple three-step pathway to the new family of CF 2CF2S-bridged alkanes and CF2S-, CF 2O-bridged alkenes and alkynes was elaborated by using catalytic olefination reaction as a key step of the s
- Nenajdenko, Valentine G.,Goldberg, Aleksey A.,Muzalevskiy, Vasily M.,Balenkova, Elizabeth S.,Shastin, Aleksey V.
-
supporting information
p. 2370 - 2383
(2013/03/28)
-
- Arylation of chloroanthraquinones by surprisingly facile Suzuki-Miyaura cross-coupling reactions
-
Chloroanthraquinones were found to undergo facile Suzuki-cross coupling with substituted phenyl boronic acids using a commercial catalyst Pd(PPh 3)4 and with Pd(PPh3)4 prepared in situ from Pd(PPh3)2Cl2 and PPh3.
- Thiemann, Thies,Tanaka, Yasuko,Iniesta, Jesus,Varghese, H. Tresa,Pannicker, C. Yohannan
-
experimental part
p. 732 - 736
(2010/03/24)
-
- Synthesis and Properties of Liquid Crystalline 4,4 -Dialkoxy-2'-Methyl-p-Terphenyls
-
A new series of laterally substituted terphenyl compounds, 4,4 -dialkoxy-2'-methyl-p-terphenyls (n = 1-12), were synthesized. Their liquid crystallinities were characterized by means of polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray difraction (XRD). The influence of the length of the terminal alkoxy groups on the liquid crystalline behavior was investigated. It was found that the compounds with shorter end chains (n a smectic A mesophase is exhibited for those with longer end chains (9 = n = 12).
- Yu, Z. N.,Tu, H. L.,Wan, X. H.,Chen, X. F.,Zhou, Q. F.
-
-
- Liquid crystal compounds, mixtures and devices
-
An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
- -
-
Page column 30
(2008/06/13)
-
- Synthesis and physical properties of thioester liquid crystals that exhibit an anti-ferro-anti phase sequencing
-
The thioester unit has been commonly used to enhance the mesophase thermal stability and phase range in numerous liquid crystal materials. In this paper we report the synthesis of a homologous series of thioesters with similar structures to AS620 {(S)-(+)
- Nassif, Larissa,Jakli, Antal,Seed, Alexander J.
-
p. 171 - 179
(2007/10/03)
-
- Liquid crystal compounds, mixtures and devices
-
An electoclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
- -
-
-
- Chiral cyclohexyl compounds
-
The present invention describes liquid crystal compounds which are suitable for use in liquid crystal devices including those which exploit the electroclinic effect.
- -
-
-