7,188 research outputs found
Cost benefit analysis and data analytics for renewable energy and electrical energy storage
No full textLevelized cost of electricity considering electrochemical energy storage cycle-life degradations
No full textReaction of piperazine with trimethylacetic arylcarboxylic anhydride; A convenient method for preparing monoacylated piperazine derivatives
No full text[[abstract]]A series of monosubstituted piperazine derivatives were obtained by the reaction of piperazine with trimethylacetic arylcarboxylic anhydrides in good yields, which were prepared in situ from arylcarboxylic acid with trimethylacetyl chloride in the presence of triethylamine.[[note]]SC
Synthesis and mesogenic properties of azo-dye liquid crystals
No full text[[abstract]]Azo-dye liquid crystals with strong amino electro-donating and moderately flexible carboxylate electron-withdrawing groups were synthesized, and their mesogenic properties were studied.[[note]]SC
New synthesis of N,N-disubstituted (4-aminophenyl)diazenyl-1,3,4-thiadiazole, and mesogenic study and molecular modeling of its H-bonded complexes with a series of m-alkoxybenzoic acid derivatives
No full text[[abstract]]A new N,N-disubstituted (4-aminophenyl)diazenyl-1,3 4-thiadiazole, an azo dye, was synthesized from the reaction of the 1-decanoyl-4-phenylpiperazine in acetone. in situ, with the diazonium salt prepared from 1,3,4-thiadiazol-2-amine and NaNO2 in H3PO4. The azo dye was found to form complexes with a series of m-alkoxybenzoic acid by intermolecular H-bonding. The mesogenic behavior of the complexes were investigated by polarizing optical microscopy and differential scanning calorimetry. A study of the representing complex by powder X-ray diffraction and molecular modeling was further undertaken to locate the H-bonding position.[[note]]SC
Synthesis and study of azo dye compounds: variation of mesogenic behaviour with length of alkyl chains
No full text[[abstract]]The mesogenic behaviours of two azo dye liquid crystals, 1 and 4, differ because of the different length of terminal alkyl chains; azo dye 1 shows a SmB phase, azo dye 4 shows nematic and SmA phases during thermal processing. The molecular stackings of these two azo dye liquid crystals are compared on the basis of crystallographic studies to explain such unexpected mesogenic behaviour.[[note]]SC
Discrete and Infinite Metallacyclic Coordination Architectures Based on a Conformationally Flexible Tripodal Aminotriazine-Derived Polypyridyl Ligand
No full text[[abstract]]A novel tripodal semi-rigid ligand, 2,4,6-tris(3-picolylamino)-1,3,5-triazine (m-H(3)tpat), consisting of a triazine central core and three pyridine donating functions attached to flexible NHCH2- arms has been designed and synthesized. The self-assembly reactions of m-H(3)tpat with copper(II) chloride and cobalt(II) chloride yielded discrete Cu-II complex [Cu2Cl4(m-H(3)tpat)(2)]center dot 2H(2)O center dot 2EtOH (1 center dot 2H(2)O center dot 2EtOH) and polymeric Co-II complex [Co(m-H(3)tpat)(2)(H2O)(2)]Cl-2 (2), respectively. Complex 1 has a metallacyclophane structure with a metal-to-ligand ratio of 2:2. Each copper(II) ion adopts a pentacoordinate square-pyramidal geometry with a N3Cl2 coordination sphere. Complex 2 exhibits an extended chain structure based on {Co-2(m-H(3)tpat)(2)} metallacyclic repeating units. Each cobalt(II) ion adopts a hexacoordinate octahedral geometry with a N2O4 coordination environment. Note that the m-H(3)tpat ligand exists in a cis-cis-cis conformation in 1 and a cis-trans-trans conformation in 2, with the central aminotriazine moiety appearing to be an asymmetric-configured allamino tautomer in both conformers. The stabilities of the two coordination-directed structures may be enhanced by intramolecular p-p interactions between two pyridine rings from two different m-H(3)tpat ligands within the metallacyclophane structure of 1 and by a set of complementary double hydrogen bonds (DA-AD arrays) between two aminotriazine moieties of two m-H(3)tpat ligands within a metallacyclic unit for 2.[[note]]SC
Mesogenic study of the H-bonded complexes of N,N-disubstituted aminophenylazo-(4)-1,3,4-thiadiazole with p-alkoxybenzoic acids
No full text[[abstract]]A 2-diazenyl substituted 1,3,4-thiadiazole formed complexes with a series of p-alkoxybenzoic acid by intermolecular hydrogen bonding. The complexes were investigated by polarizing optical microscopy and differential scanning calorimetry to understand the resulting mesogenic behaviours. A study of the complex by powder XRD and molecular modelling was further undertaken to locate the position of hydrogen bonding.[[note]]SC
Synthesis of a new azo dye sensor and its chelation with Ag+
No full text[[abstract]]A new azo dye containing thiadiazoline ring was synthesized from the reaction of the diazobenzaldehyde with O-aminothiophenol, which was characterized by NMR, IR spectroscopy and high resolution mass spectrometry. This dye compound can chelatc Ag+ in CH2C[[note]]SC
Variation in molecular stacking resulting from the different polarity of liquid crystalline molecules: synthesis and study of azo dye compounds
No full text[[abstract]]To investigate the effect of molecular polarity on the packing of liquid crystalline molecules, two liquid crystals, N,N-disubstituted aminophenylazo-4-alkylbenzenes, were synthesized and studied by single crystal structure determination. A comparison of the resulting molecular stacking with that of N, N-disubstituted aminophenylazo-4-butylbenzoate was made.[[note]]SC
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