853055-43-3Relevant academic research and scientific papers
Control the self-assembly of fluorenone-based polycatenars by tuning chain length
Zhao, Kai,Xiao, Yulong,Guo, Chunxiang,Chang, Qing,Gao, Hongfei,Cheng, Xiaohong
supporting information, p. 409 - 415 (2019/01/04)
Using Suzuki coupling reactions as key steps, a series of fluorenone-based polycatenars, consisting of a central 2,7-diphenyl-9-fluorenone core connected with the 3,4,5-trialkoxybenzoate unit via –COO- linkage at each side have been synthesized. Upon elon
Synthesis and liquid crystalline properties of novel fluorinated N-benzoyl thiourea compounds. Effect of perfluoroalkyl chains on the thermal behavior and smectic phases stability
Ili?, Monica,Micutz, Marin,Pasuk, Iuliana,Staicu, Teodora,C?rcu, Viorel
, p. 84 - 89 (2017/11/15)
A series of novel N-benzoyl-N’-aryl thiourea derivatives (BTU) bearing different number of alkoxy groups in terminal positions of benzoyl unit and a perfluorooctyl group on the other side have been designed and prepared. Their liquid crystalline properties were investigated by a combination of three techniques: polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and variable-temperature powder X-ray diffraction (XRD). Their thermal stability was studied by thermogravimetric analysis (TG). It was found that only the compounds which have only one alkoxy chain attached to benzoyl unit, 1a and 1b, show calamitic mesomorphic behavior, with smectic A and C phases being displayed. The type and stability of these mesophases are greatly influenced by the alkyl chain length as well as by the presence of perfluorooctyl group. The clearing and the mesophase ranges are significantly increased with the incorporation of perfluoroalkyl chains when compared to non-fluorinated analogues, with almost 40 °C. The attachment of additional alkoxy groups on the benzoyl moiety led to a significant decrease of the clearing points and suppression of the mesogenic character.
Hybrid photoluminescent materials containing a benzobisthiazole core for liquid crystal and gel applications
Díaz,Elgueta,Sanchez,Barberá,Vergara,Parra,Dahrouch
, p. 1804 - 1815 (2017/03/11)
Tetra- and hexacatenar amide compounds containing a linear centrosymmetric benzobisthiazole core were synthesized with good yields. These compounds were characterized and their structures confirmed by elemental analysis, and FT-IR, Maldi mass and NMR spectroscopy. All compounds exhibited excellent thermal stability up to 330 °C. The tetracatenar series containing a double substitution in the meta positions did not show mesomorphic behaviour, whereas the hexacatenar and tetracatenar series having a double substitution in the meta and para positions showed liquid crystal properties with optical textures typical of columnar mesophases corroborated by POM analysis. The mesomorphic properties were dependent on the length, number and position of alkoxy chains attached at the end of the rigid core. XRD studies of the hexacatenar series showed the hexagonal columnar structure of the mesophases. Photoluminescence properties in solution were observed in the visible region, with good quantum yields. In the solid state, these compounds behave as blue emitters and they are able to change colour with acid or base addition. The hexacatenar benzobisthiazole compound with an alkoxy chain of 14 carbons presented properties of a supergelator in chloroform, leading to the formation of a fluorescent organogel material with fluorescence emission in the blue region.
Effect of central linkages on mesophase behavior of imidazolium-based rod-like ionic liquid crystals
Cheng, Xiaohong,Su, Fawu,Huang, Rong,Gao, Hongfei,Prehm, Marko,Tschierske, Carsten
scheme or table, p. 2274 - 2285 (2012/06/30)
Two series of phenylbenzylether and benzanilide based rod-like imidazolium bromides and their nonionic precursors, the 1-phenyl-1H-imidazoles have been synthesized and the influence of the number and length of the alkyl chain(s) and the structure of the linking group in the aromatic core (-CH2O-, -COO-, -CONH-) on their mesophase self-assembly in ionic liquid crystalline phases were studied by POM, DSC and XRD. Upon decreasing the length of the N-terminal chain or by enlarging the number and length of the C-terminal chains, the sequence smectic (SmA)-hexagonal columnar (Colhex)-micellar cubic (CubI/Pm3n) was found for the ether based imidazolium salts; while only SmA and Colhex phases were observed for the related amides. The influence of the polarity of the central linkages, namely -CH 2O- and -CONH-, on the mesophase structure and stability is discussed and compared with related -COO- connected ILC.
Columnar liquid-crystalline phase from a series of symmetrical bent diphenylamine derivatives: Synthesis and characterization
Majumdar,Ansary, Inul,Roy
, p. 160 - 167 (2011/05/03)
A series of symmetrical bent-shaped materials with six alkoxy chains at the terminal position has been designed and synthesized. All except one exhibit columnar mesophase behavior. The mesomorphic properties of the compounds have been studied with the help of polaralizing optical microscopy (POM) and differential scanning colorimetry (DSC) experiments.
Self-assembly of imidazolium-based rodlike ionic liquid crystals: transition from lamellar to micellar organization
Cheng, Xiaohong,Bai, Xueqing,Jing, Shan,Ebert, Helgard,Prehm, Marko,Tschierske, Carsten
supporting information; experimental part, p. 4588 - 4601 (2010/08/19)
By using aryl-amination chemistry, a series of rodlike 1-phenyl1H- imidazole-based liquid crystals (LCs) and related imidazolium-based ionic liquid crystals (ILCs) has been prepared. The number and length of the C-terminal chains (at the noncharged end of the rodlike core) and the length of the N-terminal chain (on the imidazolium unit in the ILCs) were modified and the influence of these structural parameters on the mode of self-assembly in LC phases was investigated by polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. For the single-chain imidazole derivatives nematic phases (N) and bilayer SmA2 phases were found, but upon increasing the number of alkyl chains the LC phases were lost. For the related imidazolium salts LC phases were preserved upon increasing the number and length of the C-terminal chains and in this series it leads to the phase sequence SmA-columnar (Col)-micellar cubic (Cuby1/Pm3n). Elongation of the N-terminal chain gives the reversed sequence. Short Nterminal chains prefer an end-to-end packing of the mesogens in which these chains are separated from the C-terminal chains. Elongation of the N-terminal chain leads to a mixing of N- and C-terminal chains, which is accompanied by complete intercalation of the aromatic cores. In the smectic phases this gives rise to a transition from bilayer (SmA2) to monolayer smectic (SmA) phases. For the columnar and cubic phases the segregated end-to-end packing leads to core-shell aggregates. In this case, elongation of the N-terminal chains distorts core-shell formation and removes Cub1 and Col phases in favor of single-layer SmA phases. Hence, by tailoring the length of the N-terminal chain, a crossover from taper-shaped to polycatenar LC tectons was achieved, which provides a powerful tool for control of self-assembly in ILCs.
Heterocyclic columnar hexacatenar bisthiazoles
Tsai, Hui-Hsu Gavin,Chou, Lung-Chun,Lin, Sheng-Chia,Sheu, Hwo-Shuenn,Lai, Chung K.
supporting information; experimental part, p. 1906 - 1910 (2009/08/17)
Three new series of hexacatenar liquid crystals derived from heterocyclic bisthiazoles and bisoxazoles exhibiting columnar phases were reported, and the formation of columnar phases was strongly sensitive to central heteroatoms and/or their positions inco
Chemical triple-mutant boxes for quantifying cooperativity in intermolecular interactions
Hunter, Christopher A.,Jones, Philip S.,Tiger, Pascale,Tomas, Salvador
, p. 5435 - 5446 (2007/10/03)
Chemical double-mutant cycles have been used to quantify intermolecular functional-group interactions in H-bonded zipper complexes in chloroform. If the same interaction is measured in zippers of different overall stability, the double-mutant cycles can b
Formation of disordered hexagonal arrangements in bis(β,δ-triketonato)copper(II) complexes
Lai, Chung K.,Chen, Fuh-Gue,Ku, Yu-Ju,Tsai, Chun-Hsien,Lin, Raymond
, p. 4683 - 4687 (2007/10/03)
Two homologous series of 1-(4-alkoxy-2-hydroxyphenyl)-3-(3,4,5-trialkoxyphenyl)propane-1,3-diones and 1-(2-hydroxyphenyl)-3-(3,4,5-trialkoxyphenyl)propane-1,3-diones were prepared by base-catalysed rearrangement of 4-alkoxy-2-(3,4,5-trialkoxybenzoyloxy)ac
