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1
Content available remote Dependence of Mesomorphism on Molecular Rigidity
Rola R. R., Bhola G. N., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2015
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Vol. 47
67--76
EN
A novel smectogenic homologous series of twelve homologues synthesized and studied with a view to understand and establish the effect of molecular structure on liquid crystal properties (LC) and LC behaviors of thermotropic homologues. First (C1) to last (C16) member of a series exhibited only enantiotropically smectogenic property without showing nematic property which is absent even in the monotropic condition. Transition and melting temperature including textures of homologues were determined by an optical polarizing microscopy equipped with a heating stage, texture of a smectic phase are of the type A or C. Smectogenic phase length ranger between 5.1oC to 22.6oC. SmecticIsotropic (Sm-I) thermal stability is 153.55oC. Analytical, spectral and thermal data supported molecular structures of homologues. LC behaviors of present novel series are compared with the structurally similar homologous series. Transition curves viz. Cr-Sm and Sm-I transition curves of a phase diagram behaved in normal manner.
2
Content available remote Dependence of Liquid Crystalline Behaviors on Molecular Flexibility
Maheta S. A., Bhola G. N., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2015
|
Vol. 47
77--86
EN
A novel homologous series of thermotropic liquid crystal (LC) has been synthesized with a view to understand and establish the effect of molecular structure on liquid crystal behaviors of a series. The present LC series consist of twelve homologues (C1&enspto C16); whose mesomorphic properties commence from octyloxy (C8) homologue of a series. C8, C10&enspand C12 &enspmembers of a series are monotropic smectic and C14, C16&enspmembers are enantiotropically smectogenic. C1&enspto C7 &ensphomologues are nonmesomorphic. Nematogenic property is totally absent. Transition and melting temperatures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of smectic mesophases are focal conic three or two dimensional networking of the type A or C. Cr-I/Sm and Sm-I or I-Sm transition curves behaved in normal manner. Analytical and spectral data confirms the molecular structures of homologues. Thermal stability of smectogenic mesophase is 100.6 oC and mesomorphic phase length is very short (12.9 oC to 15.3 oC). LC properties of a present novel series are compared with the structurally similar homologous series. Present series is partly smectogenic and partly non mesomorphic with poor degree of mesomorphism and middle ordered melting type without exhibition of nematogenic behavior.
3
Content available PEG mediated eco-friendly one pot sunthesis of benzylamine coumarin derivatives using multicomponent reactant
Viradiya D. J., Kotadiya V. C, Khunt M. D., Baria B. H., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
|
2014
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Vol. 11, iss. 2
177-184
EN
A green resourceful, eco-friendly and facile protocol was developed for the synthesis of benzylamine coumarin derivatives by the reaction of 4-hydroxy coumarin, secondary amine and aromatic aldehyde in the presence of PEG400 as a solvent as well as catalyst at room temperature. A wide range of functional groups were tolerated in the developed protocol. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis. The target molecules were obtained in good to excellent yield applying this method.
4
Content available Microwave Assisted Synthesis of Some Novel Sulphonamide Bearing Pyrazolone Core Structure
Namera D. L., Kapadiya K. M., Chhatrola M. M., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 11, iss. 2
116-126
EN
We have described some novel Sulphonamide bearing pyrazoline derivatives synthesized by conventional method as well as microwave assisted method of synthesis. The reaction of 4-(3-methyl-5-oxo-4,5-dihydro-1-H-pyrazol-1-yl)benzenesulphonamide with substituted benzaldehyde in the presence of Methanol as solvent and piperidine as catalyst, generated a series of substituted pyrazolone derivatives 4a-m. The structures of all synthesized compounds are well characterized by Mass spectroscopy, FT-IR, 1H NMR and elemental analysis. After obtaining experimental data regarding the yield and the time taken for the synthesis by both the approaches, convenient and microwave assisted method, it was ascertained that the microwave assisted method is more suitable for synthesis of pyrazolone derivatives 4a-m.
5
Content available Microwave assisted synthesis of 2,5-distyryl-1,3,4-oxadiazole derivatives as anti microbial agents
Namera D. L., Rathod J. B., Maheta R. H., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 10
46--54
EN
A new series of 2,5-distyryl-1,3,4-oxadiazoles derivatives have been synthesized from cinnamic hydrazide on reaction with various cinnamic acid derivatives. The structures of synthesized compounds have been elucidated by spectral studies like IR, 1HNMR, Mass and also Elemental Analysis. Furthermore, all synthesized compounds were screened for in vitro anti microbial activity against the gram positive (Staphylococcus aureus, Pseudomonas aeruginosa) and gram negative (Escherichia coli) bacterial strain. In which some the compounds show potential inhibition against the test organisms.
6
Content available Easy, Simplistic and Green Synthesis of Various Benzimidazole and Benzoxazole Derivatives Using PEG400 as a Green Solvent
Khunt M. D., Kotadiya V. C., Viradiya D. J., Baria B. H., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2014
|
Vol. 6
61--68
EN
An improved environmentally benign procedure for the synthesis of various benzimidazole and benzoxazole derivatives using green solvent PEG400. We have optimized the reaction condition and it was found that PEG400 was believed to be best as compared to PEG200, PEG600 and PEG800 at 80 to 85 °C. This method provides a novel route for the synthesis of benzimidazole and benzoxazole derivatives. The main attractive features of this process are a mild reaction conditions, easy workup procedure and good to excellent yield. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis.
7
Content available Convenient synthesis of the 2,5-di-substituted 1,3,4-oxadiazole derivatives under microwave
Namera D. L., Bhoya U. C.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 11, iss. 2
159-166
EN
We have reported some novel 1,3,4-oxadiazole synthesized by conventional method as well as microwave assisted method. The reaction of different substituted cinnamic acid 2a-o with 2-(4-chlorophenyl) acetohydrazide by using phosphoric anhydride as catalyst, yielded a series of 2,5-di-substituted 1,3,4-oxadiazole 6a-o. The structures of all synthesized compounds are well characterized by Mass, FT-IR, 1H NMR, 13C NMR and elemental analysis. After obtaining experimental data regarding the yield and the time taken for the synthesis by both the methods, conventional and microwave assisted method, it was proved that the microwave assisted method is convenient for synthesis of this type of 2,5-di-substituted 1,3,4-oxadiazole 6a-o.
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