- Lanthanide complexes of a mesogenic Schiff's base having 1,3,4-oxadiazole moiety: Synthesis and characterization
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A liquid-crystalline Schiff's base (HL) having 1,3,4-oxadiazole moiety with an octyloxy substituent and a series of lanthanide(III) complexes [Ln(LH)3(NO3)3] (LnIII?=?La, Pr, Nd, Sm, Eu, Tb and Dy; HL?=?N-(4′-(5
- Karunakar,Yerrasani, Rajasekhar,Dubey, Ragini,Singh, Angad Kumar,Rao
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- Aggregation-induced emissions in the mesogenic BF2complexes of aroylhydrazines
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Herein, we report the synthesis of two new families of borondifluoride complexes derived from aroylhydrazines and the investigation of their mesomorphic and AIE properties. The crystallographic structure of the mesogenic complex1a-BF2(n= 8) was
- Cai, Yi-Hong,Chih, Hsin-Yun,Lai, Chung K.,Lee, Gene-Hsiang
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p. 12557 - 12568
(2021/07/25)
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- Investigating the structure-activity relationships of N’-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against Trypanosoma cruzi to design novel active compounds
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Chagas disease, caused by the protozoan Trypanosoma cruzi, is a neglected chronic tropical infection endemic in Latin America. New and effective treatments are urgently needed because the two available drugs - benznidazole (BZD) and nifurtimox (NFX) - have limited curative power in the chronic phase of the disease. We have previously reported the design and synthesis of N’-[(5-nitrofuran-2-yl) methylene] substituted hydrazides that showed high trypanocidal activity against axenic epimastigote forms of three T. cruzi strains. Here we show that these compounds are also active against a BZD- and NFX-resistant strain. Herein, multivariate approaches (hierarchical cluster analysis and principal component analysis) were applied to a set of thirty-six formerly characterized compounds. Based on the findings from exploratory data analysis, novel compounds were designed and synthesized. These compounds showed two-to three-fold higher trypanocidal activity against epimastigote forms than the previous set and were 25–30-fold more active than BZD. Their activity was also evaluated against intracellular amastigotes by high content screening (HCS). The most active compounds (BSF-38 to BSF-40) showed a selective index (SI′) greater than 200, in contrast to the SI′ values of reference drugs (NFX, 16.45; BZD, > 3), and a 70-fold greater activity than BZD. These findings indicate that nitrofuran compounds designed based on the activity against epimastigote forms show promising trypanocidal activity against intracellular amastigotes, which correspond to the predominant parasite stage in the chronic phase of Chagas disease.
- Palace-Berl, Fanny,Pasqualoto, Kerly Fernanda Mesquita,Zingales, Bianca,Moraes, Carolina Borsoi,Bury, Mariana,Franco, Caio Haddad,da Silva Neto, Adelson Lopes,Murayama, Jo?o Sussumu,Nunes, Solange Lessa,Silva, Marcelo Nunes,Tavares, Leoberto Costa
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- Nonsymmetrical cholesterol dimers constituting regioisomeric oxadiazole and thiadiazole cores: an investigation of the structure-property correlation
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Three series of chiral nonsymmetrical dimers were prepared by connecting promesogenic cholesterol to a bent structure derived from a substituted 1,3,4-oxadiazole or 1,2,4-oxadiazole or 1,3,4-thiadiazole moiety. These two mesogenic segments are interconnected through spacers of varying lengths and parity. The structures of the bent achiral unit were systematically varied with different central heterocyclic cores to understand the influence of bent angles on the thermal and gelation behavior. The bent angle of the achiral unit, which is determined by the heterocyclic core, has a major role in the stabilization of frustrated phases. Dimers based on the 1,3,4-oxadiazole unit with a more bent structure stabilized frustrated phases like blue phases and twist grain boundary phases. The bent system with a wider bent angle preferred to stabilize chiral nematic and smectic A phases. It is interesting to note that an increased bent structure reduced the mesophase stability as in the case of dimers based on the 1,3,4-oxadiazole unit, where many compounds exhibited monotropic phases. In the case of dimers with a wider bent angle, enantiotropic mesomorphism was observed. All the compounds showed blue light emission in the solution. Among these chiral dimers, only the compounds based on the 1,3,4-oxadiazole unit showed the gelation ability, which emphasizes how small structural changes like bent angle, dipole moment and the type of heteroatom in the heterocyclic unit affect the macroscopic self-assembly.
- Pradhan, Balaram,Chakraborty, Nirmalangshu,Gupta, Ravindra Kumar,Shanker,Achalkumar, Ammathnadu S.
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supporting information
p. 879 - 888
(2017/02/05)
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- Tuning the self-assembly and photophysical properties of bi-1,3,4-thiadiazole derivatives through electron donor-acceptor interactions and their application in OLEDs
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We report several shape anisotropic molecules that contain two centrally placed 1,3,4-thiadiazole units, which vary from each other with respect to the number and length of the flexible chains at the termini. The number, position and length of the periphe
- Yadav, Abhay Kumar,Pradhan, Balaram,Ulla, Hidayath,Nath, Subrata,De, Joydip,Pal, Santanu Kumar,Satyanarayan,Achalkumar, Ammathnadu S.
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supporting information
p. 9345 - 9358
(2017/09/29)
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- Mesogenic heterocycles formed by bis-pyrazoles and bis-1,3,4-oxadiazoles
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Three new series of compounds 1a-c containing multiple heterocyclic 2,5-pyrazoles, 1,3,4-oxadiazole and thiophene exhibiting mesophases were reported. Crystallographic data showed that the crystal 1a (n=8) is a linear-shaped molecule with a molecular leng
- Lin, Kuan-Ting,Lee, Gene-Hsiang,Lai, Chung K.
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p. 4352 - 4361
(2015/06/08)
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- Polarization effects in mesogenic isoxazoles and 1,3,4-oxadiazoles
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Four new series of unsymmetric isoxazoles and 1,3,4-oxadiazoles were prepared, characterized and their mesomorphic properties investigated. Isoxazoles were obtained by condensation-cyclization of β-diketones with hydroxylamine hydrochloride in refluxing T
- Lu, Li-Yang,Kuo, Hsiu-Ming,Sheu, Hwo-Shuenn,Lee, Gene-Hsiang,Lai, Chung K.
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p. 5999 - 6011
(2015/03/30)
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- 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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- Synthesis, characterization and mesomorphic investigations of ester-substituted aroylhydrazones possessing a lateral hydroxyl group
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The synthesis, characterization and investigation of a new liquid crystalline series of ester containing aroylhydrazones with a lateral hydroxyl group, N-[4-(4′-alkoxy)benzoyloxy-2-hydroxy-benzylidene]-N′- [4″-alkoxybenzoyl]hydrazine (Cm,nLH), with the same or different peripheral alkoxy chains, and some of their nickel(II) and copper(II) complexes are described. All the ligands, except those with no terminal chains on either end of the molecule, exhibit an enantiotropic SmC mesophase, as evidenced by polarizing optical microscopy and differential scanning calorimetric studies. It has been found that addition of a lateral hydroxyl group along with ester-substitution to the aroylhydrazone core increases the mesomorphic as well as thermal stability of the ligands. Also, the coordination of Ni2+ and Cu2+ with the aroylhydraozone core inhibits the mesomorphic potential of the ligands. A temperature dependent Raman study of one of the members, C12,12LH (m = n = 12) has been made to identify phase transitions and to understand the molecular rearrangement as a result of changes in intermolecular interactions at the phase transition. DFT calculations have been performed to obtain the stable electronic structure of the ligand (C6,6LH) and its nickel(II) complex.
- Singh, Sachin Kumar,Singh, Hemant Kumar,Nandi, Rajib,Kumar, Vijay,Tarcea, Nicolae,Popp, Jürgen,Singh, Ranjan K.,Singh, Bachcha
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- High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy
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Near-IR (NIR) emitting semiconducting polymer dots (Pdots) with ultrabright fluorescence have been prepared for specific cellular targeting. A series of π-conjugated polymers were synthesized to form water dispersible multicomponent Pdots by an ultrasonic
- Zhang, Xuanjun,Yu, Jiangbo,Rong, Yu,Ye, Fangmao,Chiu, Daniel T.,Uvdal, Kajsa
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p. 2143 - 2151
(2013/06/04)
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- Synthesis of new iridium complexes with substituted 1,3,4-oxadiazole and β-diketones as ligands for OLED application
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New iridium(III) complexes, viz., (OctOXD)2Ir(tta) and (OctOXD)2Ir(tmd) [OctOXD = 2-(4-butyloxyphenyl)-5-phenyl-[1,3,4] oxadiazolato-N4,C2, tta = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione, tmd = 2,2,6,6-tetramethylheptane-3,5-dio
- Kumar, Amit,Srivastava, Ritu,Kamalasanan, Modeeparampil N.,Singh, Ishwar
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experimental part
p. 937 - 942
(2012/10/08)
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- Preparation and properties of oxadiazole-containing polyacetylenes as electron transport materials
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A series of functional polyacetylenes (PAs) bearing diphenyl oxadlazole pendant groups (P1-P4) were prepared, and the resultant polymers are completely soluble In common organic solvents, Their structures and properties were characterized and evaluated by
- Wang, Xin,Guan, Shanyi,Xu, Hongyao,Su, Xinyan,Zhu, Xuhui,Li, Chun
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scheme or table
p. 1406 - 1414
(2011/03/19)
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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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- Electroactive polymers
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Electroactive polymeric arylenes and intermediates useful for making such polymers are disclosed. The present invention also provides electroactive compositions comprising the electroactive polymeric arylenes, organic electronic devices which comprise these polymers and compositions, and methods of fabricating these devices.
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Page/Page column 85
(2008/06/13)
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- ETHYNYL CONTAINING ELECTRON TRANSPORT AGENTS AND THEIR USE IN ORGANIC LUMINESCENT DEVICES
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Compounds of formula (I), compositions, organic electronic devices, and methods for preparing organic electronic devices are described. The compounds of the invention contain at least two carbon-carbon triple bonds and a heteroaromatic ring E having at least one -C=N unit. The compounds can be used as electron transport agents in organic electronic devices such as organic electroluminescent devices.
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- Synthesis and mesomorphic properties of azo compounds derived from phenyl- and thienyl-1,3,4-thiadiazole
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The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4-thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the hig
- Parra,Villouta,Vera,Belmar,Zú?iga,Zunza
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p. 1533 - 1538
(2007/10/03)
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