179031-23-3Relevant academic research and scientific papers
Exceptional dual fluorescent, excited-state intramolecular proton-transfer (ESIPT) columnar liquid crystals characterized by J-stacking and large Stokes shifts
Kanakala, Madhu Babu,Yelamaggad, Channabasaveshwar V.
, (2021/03/19)
Excited-State Intramolecular Proton-Transfer (ESIPT) fluorophores are emerging as promising future materials for electronic and biotechnological applications. ESIPT columnar (Col) liquid crystals (LCs) have been especially projected as the apt materials for advanced technological endeavors. But, there are hardly any explorations in this direction and thus, needing immediate attention. Herein we report on the synthesis, characterization, and ESIPT activity of a homologous series of novel phasmidic bis(N-salicylideneaniline) Col LCs. Optical microscopic, calorimetric and powder X-ray diffraction (XRD) studies evidence the occurrence of hexagonal columnar (Colh) phase having p6mm symmetry where the constituent slices result from the self-assembly of a pair of mesogens in a side-by-side manner facilitated by intense longitudinal π-π interactions. X-ray data confirm the absence of both directionally correlated tilting of the slices and transverse core-core interactions within the columns. Fluorescence probing clearly evidence the ESIPT occurring not only in DCM solution of the mesogens but also in their three-condensed states viz., solid, liquid crystal, and isotropic liquid phase; in general, two archetypal emission bands at ~430 nm (weak) and ~ 630 nm (strong) with large Stokes shifts (250–275 nm) of ESIPT phenomenon have been observed. The slow shift of emission maxima of the ESIPT fluorescence as a function of decreasing temperature without photoluminescence quenching coupled with the estimated tilt angle (?) of the slices normal to the columnar axis (37 to 42o), from the XRD data, confirm the formation of so-called Scheibe or J-aggregates. The redox activity, metal ion sensing ability, and solvatochromism of the mesogens have also been investigated. The study suggests that these ESIPT Col LCs with band-gap of about 3 eV can be regarded as wide-bandgap semiconducting materials having the electronic characteristics falling between those of conventional semiconductors and insulators.
Fluorenone-based organic gel molecule and preparation method and application thereof
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, (2019/04/06)
The invention belongs to the technical field of gel materials and provides a fluorenone-based organic gel molecule and a preparation method and application thereof. A fluorescent sensing film preparedfrom the fluorenone-based organic gel molecules can be
Effect of the linkages on the self-assembly and photophysical properties of 4,7-diphenyl-2,1,3-benzothiadiazole-based luminescent polycatenars
Hu, Jinliang,Xiao, Yulong,Chang, Qing,Gao, Hongfei,Cheng, Xiaohong
, (2019/05/10)
Three series of 4,7-diphenyl-2,1,3-benzothiadiazole (DBTD)based polycatenars containing a central 4,7-diphenyl-2,1,3-benzothiadiazole moiety connected to 3,4,5-trialkoxyl benzene units at both ends through ether (-OCH2-), ester (-OOC-)or amide (-HNCO-)linkages were synthesized via Suzuki coupling reaction as key step. The polarities of the linkages had great effect on their self-assembly and photophycial properties. Both ether and amide compounds were mesogens, while the ester compounds were non-mesogens. The ether compounds displayed Colhex/p6mm phases, while the amide compound displayed two kinds of columnar phases i.e. columnar rectangular phase with p2mm and columnar hexagonal phase with p6mm lattices depending on temperature. The column phases could be aligned in electric field or under mechanical shearing. The ether and amide compounds showed the significant red-shifted maximum absorption and emission. In the solid and gel states, both ether and amide compounds were yellow luminescence, while ester compounds were green luminescence.
METHOD FOR LIQUID-PHASE SYNTHESIS OF NUCLEIC ACID
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, (2015/11/16)
In this method, an oligonucleotide is prepared by using, as a synthesis unit, a novel nucleoside monomer compound represented by formula (I) [wherein X, R1, Y, Base, Z, Ar, R2, R3 and n are each as defined in Claim 1]. The
Design, synthesis, and characterization of 1,3,5-Tri(1 H-benzo[d]imidazol-2-yl)benzene-based fluorescent supramolecular columnar liquid crystals with a broad mesomorphic range
Xiong, Jin-Feng,Luo, Shi-He,Huo, Jing-Pei,Liu, Jin-Yan,Chen, Shui-Xia,Wang, Zhao-Yang
, p. 8366 - 8373 (2015/03/18)
A new kind of supramolecular columnar liquid crystal T-A with a broad mesomorphic range (up to 164.9 °C), good thermal stability, and strong fluorescence is designed and formed by the H-bonding between 1,3,5-tri(1H-benzo[d]imidazol-2-yl)benzene (T) and serial gallic acid derivatives (A). Two components are easily available because of simple routes, common reactions, high yields, commercial starting materials, and inexpensive catalysts. The introduction of the 1,2,3-triazole structure into component A makes the textures different and is slightly disadvantageous for the T-A complexes.
To assemble or fold?
Das, Anindita,Ghosh, Suhrit
supporting information, p. 11657 - 11660 (2015/05/20)
This communication reports an elegant structure formation by an amide functionalized donor (D)-acceptor (A) dyad by stepwise folding and assembly. It adopts a folded conformation by intra-chain CT-interaction that subsequently dimerizes by inter-molecular
Mesomorphic behaviour of N-benzoyl-N′-aryl thioureas liquid crystalline compounds
Ili, Monica,Bucos, Madalina,Dumitracu, Florea,C?rcu, Viorel
, p. 1 - 6 (2011/04/14)
A series of N-benzoyl-N′-aryl thiourea derivatives bearing alkoxy groups in terminal positions have been prepared and investigated for their potential liquid crystals properties. It was found that only the compounds which have only two alkoxy chains show calamitic mesomorphic behaviour, with nematic, smectic A and C phases being displayed. The type and stability of these mesophases are greatly influenced by the alkyl chain length. Successive introduction of additional alkoxy groups on the benzoyl moiety led to a significant decrease of the clearing points and suppression of the mesogenic character. Using of branched alkyl chain, 2-ethyl-hexyl, instead of normal alkyl group, led to the disappearance of mesogenic behaviour together with the lowering of the clearing temperature. The influence of chain length and number of chains is discussed.
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.
Self-assembly of novel fluorescent silole derivatives into different supramolecular aggregates: Fibre, liquid crystal and monolayer
Wan, Jun-Hua,Mao, Lin-Yan,Li, Yi-Bao,Li, Zhi-Fang,Qiu, Hua-Yu,Wang, Chen,Lai, Guo-Qiao
, p. 3195 - 3201 (2011/12/01)
Two novel organogelators based on 2,3,4,5-tetraphenylsilole functionalized with long-chain alkoxydiacylamido platforms (1a and 1b) were synthesized. The silole derivatives induced gelation of only hydrocarbon solvents and showed aggregation-induced emissi
