نتایج جستجو برای: crown ether

تعداد نتایج: 39424  

Journal: :Chemical science 2017
Si-Jia Rao Qi Zhang Ju Mei Xu-Hao Ye Chuan Gao Qiao-Chun Wang Da-Hui Qu He Tian

In this article, a six-component self-sorting process that involves three types of crown ether macrocycle and three types of cation guest molecule was carefully and thoroughly investigated. The six components include three kinds of crown ether, namely bis(p-phenylene-34-crown-10) (BPP34C10), dibenzo-24-crown-8 (DB24C8) and benzo-21-crown-7 (B21C7), and their corresponding cation guest molecules...

2013
K. Rajarajan A. Pugazhenthi M. NizamMohideen

The reaction of CdCl(2), 18-crown-6 and KI in water yields the title coordination polymer, [{K(C(12)H(24)O(6))}(2)Cd(2)I(6)](n). The potassium ion lies approximately in the plane of the crown ether, coordinated by all six crown ether O atoms and also by an iodide anion bound to a cadmium atom. A C atom of the crown ether is disordered over two positions with site occupancies of 0.77 (2) and 0.2...

Journal: :journal of nanostructures 2012
m. masteri-farahani m. bahmanyar m. mohammadikish

silica  coated magnetite  nanoparticles were  covalent  grafted with  3-aminopropyl trimethoxysilane  to give aptscmnps. reaction of  the resulted nanomaterial with 4-formyl benzo-12-crown-4 ether afforded fb12c4/aptsmnps  nanocomposite  material  in  which  the  crown ether  moiety  was  attached  through  propyl  chain  spacer. characterization of  the prepared nanocomposite was performed wit...

2012
Marzieh Vafaee Mostafa M. Amini Seik Weng Ng

The asymmetric unit of the title cocrystal, [Sn(CH(3))(C(6)H(5))Cl(2)(H(2)O)(2)]·C(10)H(20)O(5), contains two independent for-mula units. The organotin molecules exhibit a six-coordinate metal atom and are linked to the crown ether molecules by water-crown ether O-H⋯O hydrogen bonds into a linear chain running along [101]. Each coordinated water mol-ecule forms a pair of hydrogen bonds to the s...

2012
Rabindra Prasad Dhakal Tatsuya Oshima Yoshinari Baba

The polyfunctional and highly reactive bio-polymer, the chitosan was first regioselectively converted into dialkylated chitosan using dimsyl anionic solution(NaH in DMSO) and bromodecane after protecting amino groups by phthalic anhydride. The dibenzo-18-crown-6-ether, on the other hand, was converted into its carbonyl derivatives via Duff reaction prior to incorporate into chitosan by Schiff b...

2010
De-Hong Wu

The asymmetric unit of the title compound, C(8)H(12)N(+)·ClO(4) (-.)C(12)H(24)O(6), contains one half of the cationic [(C(2)H(5)-C(6)H(4)-NH(3))(18-crown-6)](+) moiety and one half of the ClO(4) (-) anion. Two O atoms of the crown ether, four C atoms and the N atom of the ethylanilinium unit and the Cl and two O atoms of the anion lie on a mirror plane. In the crystal structure, the -NH(3) (+) ...

Journal: :journal of physical & theoretical chemistry 2010
j. narafpour a. sadjadi

the do1(18c6)fi (mwli. na. k and i 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.the b3lyp/6-3i+g(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). by the aid of fundamental physical theor...

M. Bahmanyar M. Masteri-Farahani, M. Mohammadikish

Silica  coated magnetite  nanoparticles were  covalent  grafted with  3-aminopropyl trimethoxysilane  to give APTSCMNPs. Reaction of  the resulted nanomaterial with 4-formyl benzo-12-crown-4 ether afforded FB12C4/APTSMNPs  nanocomposite  material  in  which  the  crown ether  moiety  was  attached  through  propyl  chain  spacer. Characterization of  the prepared nanocomposite was performed wit...

Journal: :Analytical chemistry 2002
Eun Kyung Lee Bong Rae Cho Hui Hu Richard A Bartsch

Sixteen lipophilic N-(X)sulfonyl carbamoyl lariat ethers with polyether ring sizes of 12-crown-4, 14-crown-4, 15-crown-5, and 18-crown-6 are utilized for competitive alkali metal cation extractions from aqueous solutions into chloroform. Variation of the electron-withdrawing properties of X in the series of methyl, phenyl, 4-nitrophenyl, and trifluoromethyl allows the influence of the acidity o...

Journal: :Analytical chemistry 2006
Amy E Hilderbrand Sunnie Myung David E Clemmer

A series of crown ethers, 12-crown-4, 15-crown-5, 18-crown-6, and dibenzo-30-crown-10, are examined as a possible means of shifting the mobilities of peptide ions. In this approach, a crown ether is added to a solution containing a mixture of peptides and is electrosprayed into the gas phase in order to create distributions of peptide-crown complexes. The ion complexes have different mobilities...

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