نتایج جستجو برای: 10 diaza 18 crown 6
تعداد نتایج: 1946228 فیلتر نتایج به سال:
Experimental (IR and Raman) and theoretical (Kohn-Sham calculations) methods are used in a combined analysis aimed at refining the available structural data concerning the molecular guests in channels formed by stacked dibenzo-18-crown-6 (DB18C6) crown ether. The calculations are performed for a simplified model comprising isolated DB18C6 unit and its complexes with either H2O or H3O+ guests, w...
The reaction of 4-bromo-aniline, 18-crown-6, and perchloric acid in methanol yields the title compound, C(6)H(7)BrN(+)·ClO(4) (-)·C(12)H(24)O(6), in which the protonated -NH(3) (+) group forms three bifurcated N-H⋯O hydrogen bonds to the O atoms of the crown ether.
Complexation characteristics of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6, 18C6) with Li+ and K+ in a hydrophobic ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide under dry and humid conditions at 298.2 K were studied by 1H and 13C NMR chemical shifts. The comparison of the 1H and 13C chemical shifts of 18C6 molecule between the dry and humid IL solutions w...
The title compound, [Na(CF(3)O(3)S)(C(12)H(24)O(6))], features a sodium cation that is coordinated by eight O atoms in an irregular hexa-gonal bipyramidal environment. The equatorial positions are occupied by the six O atoms of an 18-crown-6 ether ring. In the axial positions, there is one O atom of a trifluoro-methane-sulfonate anion and an ether O atom of a symmetry-equivalent crown ether rin...
The pH-profiles of the extraction of Cs(+) into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been d...
A simple and sensitive extraction-fluorimetric method for the determination of mercury is reported. The method is based on the quantitative extractionof a ternary crown-mercury-rose Bengal complex into chloroform at pH 10 followed by fluorimetric measurements at 580 nm. A linear working range from 0.05 to 2.00 mg/mL is obtained. The relative standard deviation for 1.0 </em...
The crystal and mol-ecular strutures of two solvated forms of [K(18c6)]OAc (18c6 = 18-crown-6 = 1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane and OAc = acetate) were determined by single-crystal X-ray diffraction, namely (acetato-κ2O,O')(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ6O)potassium dihydrate, [K(CH3COO)(C12H24O6)]·2H2O (1) and (acetato-κ2O,O')aqua-(1,4,7,10,13,16-hexa-oxa-cyclo-octa-deca...
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