نتایج جستجو برای: macrocycle and caesium carbonate cs2co3 ________________________________________

تعداد نتایج: 16831944  

Journal: :Chemical communications 2010
Thomas B Faust Paul G Heath Christopher A Muryn Grigore A Timco Richard E P Winpenny

A fluoro-metallocrown selectively binds caesium, extracting it from aqueous solutions into an organic layer; the binding of Cs is monitored by (1)H-NMR of the paramagnetic complexes.

2011
Paul S. Szalay Matthias Zeller Allen D. Hunter

In the title compound, C(16)H(28)N(4)O(8)·2H(2)O, the 12-membered macrocycle has twofold crystallographic symmetry and the asymmetric unit comprises one half-mol-ecule. The four carbox-yl/carboxyl-ate groups reside on the same side of the macrocycle. The mol-ecule is a double zwitterion with two of the carb-oxy-lic acid H atoms transferred to the two N atoms on the opposite sides of the macrocy...

2014
Jwa-Min Nam Mark A. Ratner Xiaogang Liu Chad A. Mirkin

Computational simulations of macrocycle-encapsulated single-walled carbon nanotubes (SWNTs) and C60 are reported. A molecular mechanical force field method has been used to calculate the physical properties of these complexes. The calculation shows that the macrocycle-encapsulated SWNTs and C60 are more stable than free SWNTs and C60. When macrocycles are bound to SWNTs, energetically stable we...

2013
K. Showrilu K. Rajarajan M. NizamMohideen

The title compound, (NH4)2[Zn(NCS)4]·2C12H24O6·H2O, the result of the reaction of ammonium thio-cyanate, 18-crown-6 and zinc(II) chloride in aqueous solution, exhibits an unusual supra-molecular structure. The Zn atom, two of the thio-cyanate chains and a water mol-ecule, disordered over two positions, lie on a mirror plane. The macrocycle adopts a conformation with approximate D 3d symmetry. T...

Journal: :Dalton transactions 2011
Giovanni Salassa Ana M Castilla Arjan W Kleij

A metal template approach affords in high yield a tetra-Zn(salphen) macrocycle (3) which shows strong and cooperative self-assembly mediated by the formation of Zn(salphen) dimer units held together via μ(2)-phenoxo interactions. A cooperative binding mode for the tetranuclear Zn(4) macrocycle 3 is supported by comparison of UV-vis and fluorescence titration data recorded for 3 when compared wi...

Journal: :Chemical communications 2012
Aleksandra Sarnicka Przemysław Starynowicz Jerzy Lisowski

Reaction of 4-tert-butyl-2,6-diformylphenol with (1R,2R)- or (1S,2S)-1,2-diaminocyclohexane in the presence of 1 equivalent of Zn(2+) ions leads to selective formation of a chiral 2+2 macrocycle. Application of 0.5 equivalent of Zn(2+) ions under the same conditions leads to selective formation of a chiral 3+3 macrocycle, which forms a cavitand-shaped trinuclear double-decker complex with Zn(II).

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1991
mojtaba shamsipur m.k. amini

complexes of benzo-15-crown-5 macrocycle with li+ and cs+ ions were investigated by 7li and 133cs nmr in a number of nonoqueous solutions. the resulting 1:1 complex with li+ ion was found to be much more stable than that with cs+ ion. with the exception of pyridine solutions the stabilities of the complexes varied inversely with the gutmann donor number of the solvents. some indirect evidence f...

2017
Liva Dzene Eric Ferrage Jean-Christophe Viennet Emmanuel Tertre Fabien Hubert

Radioactive caesium pollution resulting from Fukushima Dai-ichi and Chernobyl nuclear plant accidents involves strong interactions between Cs+ and clays, especially vermiculite-type minerals. In acidic soil environments, such as in Fukushima area, vermiculite is subjected to weathering processes, resulting in aluminization. The crystal structure of aluminized clays and its implications for Cs+ ...

2011
L. Schiesko P. McNeely

Systematic Langmuir probe measurements were performed during the caesium (Cs) conditioning of the IPP prototype negative hydrogen ion source. Conditioning consists of slowly injecting caesium into the source in order to increase the extracted negative ion current and minimize the co-extraced electrons. This process usually takes several days. Measurements were taken near the plasma grid where t...

Journal: :Organic & biomolecular chemistry 2015
Marco Caricato Arnaud Delforge Davide Bonifazi Daniele Dondi Andrea Mazzanti Dario Pasini

We describe the design and synthesis of a novel functionality-rich, homochiral macrocycle, possessing the overall molecular D2 symmetry, in which multivalency is introduced into the covalent framework by means of four suitably positioned pyridine moieties. The macrocycle synthesis is carried out with functionalized, enantiopure 1,1'-binaphthyl synthons as the source of chirality by means of a r...

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