136954-83-1Relevant academic research and scientific papers
Mesophase behavior of new linear supramolecular hydrogen-bonding complexes
Ahmed,Hagar,Aljuhani
, p. 34937 - 34946 (2018)
Thermal and mesophase behavior of four new series of hydrogen-bonded supramolecular complexes (In/IIm) were investigated by differential scanning calorimetry and phases identified by polarized light microscopy. All hydrogen-bonded complexes formed from 4-
New wide-stability four-ring azo/ester/Schiff base liquid crystals: Synthesis, mesomorphic, photophysical, and DFT approaches
Ahmed, Hoda. A.,Ahmed, Nagwa H. S.,Hagar, Mohamed,Saad, Gamal R.
, p. 9643 - 9656 (2020/03/19)
New four-groups-based azo/ester/Schiff base liquid crystals, ((4-substitutedphenylimino)methyl)phenyl 4-[2-(4-alkoxyhenyl)diazenyl]benzoate, Ina-d, were synthesized and analyzed for their mesomorphic stability and optical activity. In these com
A Carbon Dioxide Bubble-Induced Vortex Triggers Co-Assembly of Nanotubes with Controlled Chirality
Zhang, Ling,Zhou, Laicheng,Xu, Na,Ouyang, Zhenjie
, p. 8191 - 8195 (2017/06/30)
It is challenging to prepare co-organized nanotube systems with controlled nanoscale chirality in an aqueous liquid flow field. Such systems are responsive to a bubbled external gas. A liquid vortex induced by bubbling carbon dioxide (CO2) gas was used to stimulate the formation of nanotubes with controlled chirality; two kinds of achiral cationic building blocks were co-assembled in aqueous solution. CO2-triggered nanotube formation occurs by formation of metastable intermediate structures (short helical ribbons and short tubules) and by transition from short tubules to long tubules in response to chirality matching self-assembly. Interestingly, the chirality sign of these assemblies can be selected for by the circulation direction of the CO2 bubble-induced vortex during the co-assembly process.
Long-range ordering of highly charged self-assembled nanofilaments
Palmer, Liam C.,Leung, Cheuk-Yui,Kewalramani, Sumit,Kumthekar, Rohan,Newcomb, Christina J.,Olvera De La Cruz, Monica,Bedzyk, Michael J.,Stupp, Samuel I.
, p. 14377 - 14380 (2015/01/16)
Charged nanoscale filaments are well-known in natural systems such as filamentous viruses and the cellular cytoskeleton. The unique properties of these structures have inspired the design of self-assembled nanofibers for applications in regenerative medicine, drug delivery, and catalysis, among others. We report here on an amphiphile of completely different chemistry based on azobenzene and a quaternary ammonium bromide headgroup that self-assembles into highly charged nanofibers in water and orders into two-dimensional crystals. Interestingly small-angle X-ray scattering (SAXS) shows that these fibers of 5.6 nm cross-sectional diameter order into crystalline arrays with remarkably large interfiber spacings of up to 130 nm. Solution concentration and temperature can be adjusted to control the interfiber spacings, and addition of salt destroyed the crystal packing indicating the electrostatic repulsions are necessary for the observed ordering. Our findings here demonstrate the universal nature of this phenomenon in systems of highly charged nanoscale filaments.
Monotropic or enantiotropic mesophases? Liquid-crystalline and solid state polymorphism 4-Chloro-1,3-phenylene bis-[4-(4-alkyloxyphenylazo)benzoates
Niezgoda, Izabela,Pociecha, Damian,Galewski, Zbigniew
, p. 59 - 66 (2014/06/09)
This article presents a homologous series of bent-core molecules consisting of a 4-chlororesorcinol as a central unit and 4-[(4-alkyloxyphenyl)diazenyl] benzoic acids as wings. With the use of polarizing optical microscopy (POM), thermal analysis (TOA) and differential scanning calorimetry (DSC) the mesogenic properties were detected. Furthermore, the X-ray diffraction (XRD) measurements were also performed for selected samples. Compounds of the above mentioned series form nematic, B6, and smectic C mesophases. An interesting phenomenon in the solid phase polymorphism was observed in some cases. In our experiment one crystalline form (CrI) melts to nematic phase while the second form (CrII) melts at higher temperature directly to isotropic phase. The solid state modification determines whether a monotropic and an enantiotropic mesophase is observed.
4-cyanoresorcinol-based bent-core mesogens with azobenzene wings: Emergence of sterically stabilized polar order in liquid crystalline phases
Alaasar, Mohammed,Prehm, Marko,May, Kathrin,Eremin, Alexey,Tschierske, Carsten
, p. 1703 - 1717 (2014/04/03)
A new series of azobenzene containing bent-core molecules incorporating 4-cyanoresorcinol as the central core unit exhibiting cybotactic nematic, rectangular, columnar, and different types of tilted smectic (SmC) phases are synthesized. The mesophase behavior and phase structures are characterized in bulk and freely suspended films using a variety of experimental techniques. Depending on the chain length and temperature a series of different mesophases is observed in these compounds, ranging from cybotactic nematic via paraelectric SmC phases, polarization randomized SmCsPR phases to ferroelectric and antiferroelectric SmC phases, associated with increasing size and correlation length of the polar domains. Spontaneous formation of chiral domains is observed in the paraelectric SmC and the SmCsPR phases and discussed in relation with superstructural chirality, bend elastic constants, and surface effects. Development of polar order in tilted smectic liquid crystalline phases (SmC) of bent-core mesogens is found to take place with increasing polar domain size in a series of distinct phases via a paraelectric and a new randomized polar SmC phase (SmCsPR) to a ferroelectric phase, which then becomes modulated and finally changes to an antiferroelectric phase.
Self-assembled 1,2-bis[4-(4-(10-decyloxy)phenylazo)]benzoylhydrazine dimer and its hydrogen-bonded complexes
Yeap, Guan-Yeow,Balamurugan, Subramanian,Rakesh, Samikannu,Han, Chun-Chieh,Lin, Hong-Cheu
, p. 424 - 431 (2013/09/02)
We report the synthesis and investigation of a new self-assembled benzoylhydrazine-based compound, namely 1,2-bis[4-(4-(10-decyloxy)phenylazo)] benzoylhydrazine and their hydrogen-bonded complexes with different carboxylic acid derivatives, of which some exhibit liquid crystalline properties and some are non-mesogens. The conversion of the non-liquid crystalline target compound that is free from carboxylic acid to liquid crystalline complexes containing various carboxylic acids can probably be rationalised through the breaking of intermolecular hydrogen bonding within the supramolecular assembly by carboxylic acid dopants. The enhancement of liquid crystalline properties of benzoylhydrazine compounds with respect to various carboxylic dopants is documented. Other salient features can be exemplified by the formation of discotic columnar phase as shown by the azo-linkage containing 4-(4′-(10-decyloxy)phenylazo)benzoic acid-doped complex.
Hockey stick liquid crystals based on a 2,5-asymmetric disubstituted [1,3,4]oxadiazole core
Cioanca, Elena-Raluca,Elena, Luiza Epure,Carlescu, Irina,Lisa, Gabriela,Wilson, Daniela,Hurduc, Nicolae,Scutaru, Dan
experimental part, p. 51 - 63 (2012/05/05)
The article describes the liquid-crystalline properties of some 2,5-asymmetric disubstituted [1,3,4]oxadiazole derivatives containing an azo and an ester linkage obtained through esterification of 2-(4-methoxyphenyl)-5-(4- hydroxyphenyl)-[1,3,4]oxadiazole with a series of 4-(4-alkoxyphenyl)-benzoic acids containing 6-10 and 18 aliphatic carbon atoms. All reported compounds present liquid-crystalline properties, evidenced by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM), with nematic and smectic C type structures, with very large range of stability of mesophases (between 130°C and 198°C on heating and 134°C and 214°C on cooling). Copyright Taylor & Francis Group, LLC.
The intrinsic photoferroelectric effect in the smectic C* phase of a chiral azobenzene
Saipa, Alexander,Osipov, Mikhail A.,Lanham, Kenneth W.,Chang, Catherine H.,Walba, David M.,Giesselmann, Frank
, p. 4170 - 4177 (2008/02/04)
The ferroelectric properties in the liquid-crystalline smectic C* phase of the chiral mesogenic azobenzene (S)-4-(4-decyloxy-phenylazo)benzoic acid 4-(1-methylhexyloxy)-3-nitro-phenyl ester ('W470') were studied and found to be strongly dependent on the i
Synthesis and mesomorphic properties of γ-substituted β-diketones and their dicarbonylrhodium(I) complexes
Han, Jie,Zhang, Liang Fu,Wan, Wen
, p. 86 - 93 (2007/10/03)
Five series of 3-(C10H21O-Ph-X-Ph-Y-) substituted pentane-2,4-diones and their dicarbonylrhodium(I) complexes, namely, series 1: X = -CH = CHCOO- and Y = -COO-, series 2: X = -CH - CHCOO-; and Y = -CH=CHCOO-, series 3: X = -COO- and
