- Synthesis and anticonvulsant activity evaluation of 4-butyl-5-(4- alkoxyphenyl)-2H-1,2,4-triazole-3(4H)-ones
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A series of 4-butyl-5-(4-alkoxyphenyl)-2H-1,2,4-triazole-3(4H)-ones (6a-6u) was designed and synthesized. The anticonvulsant effects and neurotoxicity of the compounds were evaluated with maximal electroshock test and rotarod test. Among the synthetic compounds, 4-butyl-5-(4-(2-fluorinebenzyl)phenyl)-2H-1,2,4- triazole-3 (4H)-one (6k) was the most potent with ED50 value of 27.4 mg/kg and protective index (PI = TD50/ED50) value of 12.0. Besides the anti-MES efficacy, the potency of compound 6k against seizures induced by pentylenetetrazole (PTZ), 3-mercaptopropionic acid (3-MP), and bicuculline (BIC) was also established, which suggested that the mechanisms of action including enhancing of GABAergic activity might be involved in its anticonvulsant activity.
- Zhu, Zi-Shi,Wang, Shi-Ben,Deng, Xian-Qing,Liu, Da-Chuan,Quan, Zhe-Shan
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p. 628 - 635
(2014/05/20)
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- New mesomorphic benzothiazol derivatives: Synthesis and characterization
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In this paper, the synthesis of new mesomorphic benzothiazolyl derivatives, 6-ethoxy-2-[4-(4-alkyloxybenzoyloxy)benzylidenamino]benzothiazoles, is presented. The structures of the title compounds were elucidated using spectroscopic techniques, such as FT-IR, NMR (1H and 13C), elemental analysis and EI-MS. The mesomorphic behaviours of these compounds were determined by differential scanning calorimetric and polarizing optical microscopic techniques. Compounds exhibited nematic and tilted smectic phases upon heating from crystal phase. An obvious odd-even effect was observed in this homologous series.
- Koh, Teck-Ming,Ha, Sie-Tiong,Yeap, Guan-Yeow,Lin, Hong-Cheu
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p. 926 - 928
(2013/09/24)
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- A new way to access chiral liquid crystals: Organocatalyst-mediated synthesis of chiral rod-like liquid crystals
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In this article, an asymmetric organocatalytic way to prepare chiral liquid crystals from non-chiral starting materials was described. By using L-proline as the organocatalyst, several new chiral rod-like liquid crystals that are elusive with traditional methods were prepared. In addition, a series of novel enone-containing rod-like liquid crystals were also obtained as side-products. Mesomorphic properties of all new compounds were studied by Polarized Optical Microscope and Differential Scanning Calorimetry. Copyright Taylor & Francis Group, LLC.
- Wang, Li,Liu, Xiao-Jun,Huang, Ping,Gong, Qing-Ping,Li, Yong-Hong,Wang, Bi-Qin,Zhao, Ke-Qing
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scheme or table
p. 53 - 59
(2012/07/14)
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- Self-assembly of imidazolium-based rodlike ionic liquid crystals: transition from lamellar to micellar organization
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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.
- Cheng, Xiaohong,Bai, Xueqing,Jing, Shan,Ebert, Helgard,Prehm, Marko,Tschierske, Carsten
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supporting information; experimental part
p. 4588 - 4601
(2010/08/19)
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- Oxime Carbamate-Discovery of a series of novel FAAH inhibitors
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A series of novel oxime carbamates have been identified as potent inhibitors of the key regulatory enzyme of the endocannabinoid signaling system, fatty acid amide hydrolase (FAAH). In this Letter, the rationale behind the discovery and the biological evaluations of this novel class of FAAH inhibitors are presented. Both in vitro and in vivo results of selected targets are discussed, along with inhibition kinetics and molecular modeling studies.1.
- Sit,Conway, Charles M.,Xie, Kai,Bertekap, Robert,Bourin, Clotilde,Burris, Kevin D.
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supporting information; experimental part
p. 1272 - 1277
(2010/06/17)
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- Hydrogen bonding versus van der waals interactions: Competitive influence of noncovalent interactions on 2d self-assembly at the liquid-solid interface
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The structures of the self-assembled monolayers of various 4-alkoxybenzoic acids physisorbed at the liquid-solid interface were established by employing scanning tunnelling microscopy (STM). This study has been essentially undertaken to explore the competitive influence of van der Waals and hydrogen-bonding interactions on the process of two-dimensional self-assembly. These acid derivatives form hydrogen-bonded dimers as expected; however, the dimers organise themselves in the form of relatively complex lamellae. The characteristic feature of these lamellae is the presence of regular discommensurations or kinks along the lamella propagation direction. The formation of kinked lamellae is discussed in light of the registry mechanism of the alkyl chains with the underlying graphite substrate. The location of the kinks along a lamella depends on the number (odd or even) of carbon atoms in the alkyl chain. This result indicates that concerted van der Waals interactions of the alkyl chain units introduce the odd/even chain-length effect on the surface-assembled supramolecular patterns. The odd/even effects are retained even upon complexation with a hydrogen-bond acceptor. However, as the solvent is changed from 1-phenyloctane to 1-octanoic acid, the kinked lamellae as well as the odd/even effects disappear. This solvent-induced convergence of supramolecular patterns is attained by means of co-crystallisation of octanoic acid molecules in the 2D crystal lattice, which is evident from high-resolution STM images. The solvent co-adsorption phenomenon is discussed in terms of competing van der Waals and hydrogen-bonding interactions. Discontinuous but ordered: Noncovalent interactions play an exceedingly decisive role in the process of self-assembly. To gain better insight into the role of noncovalent interactions, the competitive influence of hydrogen-bonding and van der Waals interactions was explored in the monolayers formed by simple 4-alkoxybenzoic acids at the liquid-solid interface (see image). Copyright
- Mali, Kunal S.,Lava, Kathleen,Binnemans, Koen,Defeyter, Steven
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supporting information; experimental part
p. 14447 - 14458
(2011/03/21)
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- Synthesis and gelation behavior of 4′-propyl-1,1′- bi(cyclohexyl)-4-one 4-alkoxybenzoylhydrazone
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A series of new alkoxybenzoylhydrazones of 4′-propyl-1,1′- bi(cyclohexyl)-4-one were prepared as novel low molecular weight organogelators (LMOGs). Their gelation behaviors in 10 solvents were tested. Some of the compounds could form stable gels in bulk o
- Li, Juan,Chen, Pei,Chen, Xinbing,An, Zhongwei,Li, Yan
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scheme or table
p. 1329 - 1330
(2011/02/17)
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- Self-assembly of highly luminescent bi-1,3,4-oxadiazole derivatives through electron donor-acceptor interactions in three-dimensional crystals, two-dimensional layers and mesophases
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We report on the synthesis and self-assembly of a new series of highly luminescent bi-1,3,4-oxadiazole derivatives [2,2′-bis(4-alkoyphenyl)-bi-1, 3,4-oxadiazole, BOXD-n, n = 1, 3, 4, 5, 6, 7, 10, 16]. Fully conjugated conformations were demonstrated either by computer simulation or in a single-crystal state. Well-defined 3D donor-acceptor (DA) architectures with strong face-to-face and edge-to-edge donor-acceptor interactions were observed in the single-crystal structure of BOXD-1. Highly oriented face-on two-dimensional DA layered structures due to edge-to-edge donor-acceptor interactions were observed on highly oriented pyrolytic graphite (HOPG) in BOXD-7 and BOXD-16. Nematic phase, smectic C phase with large tilted angle ( ≈ 50°) and relatively large transition enthalpic values and a highly ordered smectic X phase were demonstrated in BOXD-n (n = 5, 6, 7, 8, 10, 16) through tailing the terminal chains and relatively large scale monodomains were prepared in the smectic X phase of BOXD-5 even without any surface treatment. Strong blue fluorescent emissions were observed in BOXD-6 either in cyclohexane (ΦF ≈ 92%) or in solid state (ΦF ≈ 57%). The donor-acceptor interactions between alkyoxyphenylene rings and 1,3,4-oxadiazole rings were thought to be the driving force for the molecules to self-assemble into a large angle tilted layered structure.
- Qu, Songnan,Chen, Xiaofang,Shao, Xiang,Li, Fan,Zhang, Hongyu,Wang, Haitao,Zhang, Peng,Yu, Zhixin,Wu, Kai,Wang, Yue,Li, Min
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scheme or table
p. 3954 - 3964
(2010/02/28)
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- Synthesis and characterization of 1,3,4-oxadiazole derivatives containing alkoxy chains with different lengths
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The synthesis, optical properties, electrochemical properties, electronic structures and applications in electroluminescent device of three series of 1,3,4-oxadiazole derivatives, 1,4-bis[(4-methylphenyl)-1,3,4-oxadiazolyl]phenylene (OXD1), 5,5′-di-(4-methyl)-2,2′-p-(2,5-bisalkoxyphenylene)-bis-1,3,4 -oxadiazole (OXD2-n) and 1,4-bis[(4-alkoxyphenyl)-1,3,4-oxadiazolyl]phenylene (OXD3-n) are reported. The molecular structures of the oxadiazole compounds were confirmed by FT-IR, 1H NMR spectroscopy and elemental analysis. The optical and electrochemical properties of the compounds were investigated by UV-vis absorption and photoluminescence spectroscopy as well as cyclic voltammetry. The results show that introduction of two alkoxy groups whose electron-donating ability is stronger than that of methyl groups increases the electron density of the conjugated segment of OXD2-n (with side-on alkoxy substituents) and OXD3-n (with end-on alkoxy substituents), and thus leads to the absorption maximum bathochromic-shift compared to that of OXD1. The HOMO and LUMO energy levels of the compounds studied are in the range of -2.78 to -2.89 and -5.75 to -6.20 eV. Calculations on the representative compounds by the Dmol3 package of MS Modeling 3.0 revealed that the increase of energy levels in both OXD2-n and OXD3-n was due to the change of the frontier molecular orbital distribution in the central benzene ring. The light-emitting devices have been fabricated using blends of MEH-PPV and these compounds as emissive layers, among which, maximum brightness up to 11810 cd m-2 (8.5 V) has been observed, which is 40 times brighter than that with MEH-PPV. The result of the devices suggested that oxadiazole derivatives studied function well as electron-transporting materials and can be used in LEDs, and thus to enhance the efficiency of LEDs.
- Zhang, Xiao-bing,Tang, Ben-chen,Zhang, Peng,Li, Min,Tian, Wen-jing
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- Study of activation energy and order of reaction of some liquid crystals
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Liquid crystals of the type p-phenylene-di-p-n-alkoxy benzoate have been prepared. Kissinger isothermal decomposition method has been used for determination of activation energy values of liquid crystals. Kissinger's assessment for shape index of DTA peaks is used to find the order of reaction. There is no direct relationship between the carbon atoms in terminal methylene groups and Ea values. Order of reaction value decreases with increase in heating rate upto carbon atoms 10 in the terminal methylene group but beyond this the order increases or decreases.
- Mundhe
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p. 246 - 249
(2007/10/03)
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