共查询到20条相似文献,搜索用时 15 毫秒
1.
H. T. Srinivasa 《Liquid crystals》2017,44(10):1506-1514
A series of new chalcones with four aromatic rings is synthesised and characterised. The chemical structures of chalcones are evaluated by Fourier transform-infrared spectroscopy, elemental analysis, 1H and 13C nuclear magnetic resonance spectroscopic techniques. The compounds were investigated for liquid crystalline properties using differential scanning calorimetry and polarising optical microscopy with hot stage. The results indicate that the formation of mesophase type is dependent on the alkyl chain length at one end of the molecule. Compounds 9a–d with relatively shorter chains show SmA and nematic mesophases, whereas 9e–g exhibit SmC and SmA mesophases. Compound 9h having a cyano group at one end, exhibit SmA and nematic mesophases. 相似文献
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Treatment of 1-(5-acetyl-3,4-dimethythieno[2,3-b]thiophene-2yl)ethanone (1) with dimethylformamide dimethyl acetal afforded enaminone derivative 2, which reacted with amino derivatives to give the corresponding bis-pyrimidine, bis-pyrazole, bis-triazolo-pyrimidine and bis-benzoimidazopyrimidine derivatives. 相似文献
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Novel ditopic receptors for guanosine have been prepared and characterised. Their association constants with a lipophilic guanosine derivative are somewhat smaller than the expected values for a guanosine-cytidine base pair, but remain in a useful range for building supramolecular structures. 相似文献
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Ram C. Maurya Dinesh C. Gupta Rajesh Shukla Raj K. Shukla Nalmas Anandam Mannar R. Maurya 《Transition Metal Chemistry》1986,11(12):463-464
Summary A new series of cyano-substituted nitrosylchromium(I) complexes having octahedral stereochemistry around the metal ion, and of general formula, [CrNO(CN)2(L)2(H2O)] (L =o-,m- andp-phenetidines oro-,m-, andp-anisidines) have been isolated in the solid state by interaction of potassium pentacy-anonitrosylchromate(I) monohydrate with the appropriately substituted aniline. The complexes, which have been characterised by elemental analysis, conductance, molecular weight determination, magnetic measurements, e.s.r. and i.r. spectral studies, contain chromium(I) in a low-spin d5-configuration. 相似文献
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The synthesis and characterisation of two binaphthyl trisilanes is described. Reaction between 2,2′-dilithio-1,1′-binaphthyl and 1,3-dichlorohexamethyltrisilane gave 3,3,4,4,5,5-hexamethyl-4,5-dihydro-3H-3,4,5-trisilacyclohepta[2,1-a;4,3-a′]binaphthalene (3). Compound 3 was characterised by 1H, 13C and 29Si NMR spectroscopy and a crystal structure analysis. Reaction between 2,2′-dilithio-1,1′-binaphthyl and 1,3-bis(trifluoromethanesulfonyloxy)-1,1,2,3,3-pentamethyltrisilane, generated in situ by treatment of 1,3-diphenyl-1,1,2,3,3-pentamethyltrisilane with trifluormethanesulfonic acid, gave 3,3,4,5,5-pentamethyl-4,5-dihydro-3H-3,4,5-trisilacyclohepta[2,1-a;4,3-a′]binaphthalene (7). Analysis by 1H, 13C and 29Si NMR spectroscopy revealed that 7 had a very similar structure to 3. 相似文献
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W.A. Shantha Nandana Jack Passmore D.C. Neil Swindells Peter S. White Chi-Ming Wong 《Journal of fluorine chemistry》1982,21(1):14
Antimony pentafluoride acts as a useful oxidising agent towards many non-metals, giving interesting cations, and in the process is itself reduced. It would be helpful to know what the reduced products are, and under what conditions they are formed. Therefore, SbF5 and the known SbF5·SbF3(1) in AsF3 solution were reduced by iodine and/or PF3 giving crystals of the new adduct, (SbF3)6(SbF5)5 [Monoclinic, a = 11.638(1), b = 8.995(1), c = 16.723(3) ā, β = 106.81(1)°, P21/c]; (SbF3)5(SbF5)3 [Orthorhombic, a = 19.187(9), b = 15.890(2), c = 15.713(3) ā, Pnma] and (SbF3)3SbF5 [Monoclinic, a = 10.895(3), b = 10.941(3), c = 4.772(1) ā, β = 96.66(3)°, P21/m]. (SbF3)3SbF5 seemed to be the most reduced adduct, no evidence was obtained for (SbF3)n(SbF5) n > 3, under these conditions. The (SbF3)6(SbF5)5 adduct has a Raman spectrum identical to that reported by Gillespie(2) and coworkers for an adduct of approximate composition SbF3·SbF5 and has a very different structure to that of (SbF3)6(SbF6)5 reported by Edwards.(3) The crystal structures of the new adducts will be discussed and the cations they contain compared with those found in SbF3·SbF5(1) and (SbF5)6(SbF5)5(3) (Edward's form). 相似文献
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É. O. Gogrichiani I. Sh. Chikvaidze L. I. Dzhibladze M. B. Tsotadze Sh. A. Samsoniya N. N. Suvorov 《Chemistry of Heterocyclic Compounds》1994,30(10):1170-1173
New indole derivatives — 2-ethoxycarbonyl-5(p-acetylphenyl)indole andpara-substituted 2-diphenylindoles —key compounds for synthesis of new bisindoles, were synthesized from 4-acetyl-4-nitrodiphenyl.I. Dzhavakhishvili Tbilisi State University, Tbilisi 380028. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1351–1354, October, 1994. Original article submitted September 15, 1994. 相似文献
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The reaction between 4‐dimethylaminopyridine (DMAP) and 2‐bromoacetophenone(s) readily gives 1‐ [2‐(4‐substitutedphenyl)‐2‐oxoethyl]‐4‐(dimethylamino)pyridinium bromide ( 1–14 ). Action of aqueous NaOH on 1–8 generates the corresponding pyridinium ylide ( 15–22 ), which is isolated as a colored stable crystalline solid. Addition of 15–22 to dimethylacetylene dicarboxylate (DMAD) gives dimethyl 3‐(substitutedbenzoyl)‐7‐(dimethylamino)indolizine‐1,2‐dicarboxylate ( 23–30 ) in 46–62% yield. 相似文献
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S. B. Tambi Madhu Anand Vineeta Taneja C. L. Gupta R. L. Mital 《Journal of heterocyclic chemistry》1983,20(3):803-805
The synthesis of various 3-substituted derivatives of 7-fluorophenothiazin-3-ol and their 5-oxides is described. The ir, uv and mass spectral data are also included. 相似文献
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Silica gel was firstly functionalised with aminopropyltrimethoxysilane obtaining the aminopropylsilica gel (APSG). The APSG was reacted subsequently with morin yielding morin-bonded silica gel (morin-APSG). The structure was investigated and confirmed by elemental and thermogravimetric analyses, IR and (13)C NMR spectral studies. Morin-APSG was found to be highly stable in common organic solvents, acidic medium (<2molL(-1) HCl, HNO(3)) or alkaline medium up to pH 8. The separation and preconcentration of Ag(I), Au(III), Pd(II), Pt(II) and Rh(III) from aqueous medium using morin-APSG was studied. The optimum pH values for the separation of Ag(I), Au(III), Pd(II), Pt(II) and Rh(III) on the sorbent are 5.7, 2.2, 3.7, 3.7 and 6.8, giving rise to separation efficiencies of 43.9, 85.9, 97.7, 60.9 and 91.0%, respectively, where the activity was found to be >90% in the presence of acetate ion. The ion sorption capacity of morin-APSG towards Cu(II) at pH 5.5 was found to be 0.249mmolg(-1) where the sorption capacities of Ag(I) and Pd(II) were 0.087 and 0.121mmolg(-1) and 0.222 and 0.241mmolg(-1) at pH 2.2 and 5.7, respectively. This indicates a 1:1 and 1:2 morin/metal ratios at pH 2.2 and 5.7, respectively. Complete elution of the sorbed metal ions was carried out using 10mL (0.5molL(-1) HCl+0.01molL(-1) thiourea) in case of Au(III), Pd(II), Pt(II) and Rh(III) and 10mL 0.5molL(-1) HNO(3) in case of Ag(I). Morin-APSG was successfully employed in the separation and preconcentration of the investigated precious metal ions from some spiking water samples yielding 100-folds concentration factor. The relative standard deviation (R.S.D.) and the T-test (|t|(1)) were calculated. 相似文献
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A new helically chiral hexacyclic phosphine, containing one thiophene ring was prepared in good yield via a five-step sequence involving a palladium-catalysed Mizoroki-Heck coupling reaction and classical oxidative photocyclisation. A mononuclear air stable ruthenium complex of this phosphine was also prepared and characterised. 相似文献
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Two new bisazomethine diols were prepared from terephthalaldehyde and aromatic or aliphatic aminoalcohols. The structure of the diols with bisazomethine moieties was confirmed by 1H-NMR, IR, UV spectroscopy and elemental analysis. Bisazomethine aliphatic diol exhibited a smectic phase that has been identified by means of polarizing microscopy and differential scanning calorimetry. By using these diols as partners in polyaddition reaction between poly(tetramethylene oxide)diol of 2000 average molecular weight, tolylene-2,4-diisocyanate (as 2,4- and 2,6-TDI, 80:20 v/v isomers mixture) and bisazomethine diol (1:3:2 molar ratio), two polyazomethine-urethanes were synthesized. Polyazomethine-urethanes with a higher concentration of poly-Schiff's base units were also obtained by reacting the above bisazomethine diols with the same diisocyanate (1:1 molar ratio). All polymers were characterized by viscometry, elemental analysis, IR, UV, 1H-NMR spectroscopy and TGA techniques. 相似文献
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C.J. Marsden 《Journal of fluorine chemistry》1975,5(5):423-433
The preparation and characterisation of CF3SePF2, CF3SeSi(CH3)3 and CF3SeTl(CH3)2 are described. The vibrational and n.m.r. spectra of these compounds are presented and discussed. 相似文献