نتایج جستجو برای: cryptand 222

تعداد نتایج: 8797  

Journal: :Organic & biomolecular chemistry 2009
Ming Liu Shijun Li Mingming Zhang Qizhong Zhou Feng Wang Menglong Hu Frank R Fronczek Ning Li Feihe Huang

Two three-dimensional catenanes have been successfully synthesized from a bis(m-phenylene)-32-crown-10-based cryptand and paraquat derivatives in reasonable yields.

2009
Mondher Dhifet Mohamed Salah Belkhiria Jean-Claude Daran Habib Nasri

As part of a systematic investigation for a number of Fe(II) porphyrin complexes used as biomimetic models for cytochrome P450, crystals of the title compound, [K(C(18)H(36)N(2)O(6))][Fe(II)(C(64)H(64)N(8)O(4))(HS)], were prepared. The compound exhibits a non-planar conformation with major ruffling and saddling distortions. The average equatorial iron-pyrrole N atom [Fe-N(p) = 2.102 (2) Å] bond...

Journal: :Angewandte Chemie 2010
Nipuni-Dhanesha H Gamage Yujiang Mei Joel Garcia Matthew J Allen

The magnetic and optical properties of the divalent state of europium make this ion extremely attractive for use in materials, catalysis, luminescence, magnetic, and diagnostic-medical applications. A major hindrance to the use of Eu in many of these applications is the extreme propensity of the ion to oxidize to Eu, especially in aqueous solution. Research efforts aimed at increasing the stabi...

Journal: :Chemistry 2013
Giuseppe Alibrandi Valeria Amendola Greta Bergamaschi Riccardo Dollenz Luigi Fabbrizzi Maurizio Licchelli Carmelo Lo Vecchio

The combined activity of the 1.1.1-cryptand and of a dicopper(II) bistren cryptate complex including chloride makes the Cl(-) ion be continuously and slowly delivered to the solution, without any external intervention. The 1.1.1-cryptand slowly releases OH(-) ions, according to a defined kinetics, and each OH(-) ion displaces a Cl(-) ion from the cryptate. Chloride displacement induces a sharp ...

2016
Dmitri V. Konarev Leokadiya V. Zorina Salavat S. Khasanov Alexey A. Popov Akihiro Otsuka Hideki Yamochi Gunzi Saito Rimma N. Lyubovskaya

Reduction of scandium nitride clusterfullerene, Sc3N@Ih-C80, by sodium fluorenone ketyl in the presence of cryptand[2,2,2] allows the crystallization of the {cryptand[2,2,2](Na(+))}2(Sc3N@Ih-C80(-))2·2.5C6H4Cl2 (1) salt. The Sc3N@Ih-C80˙(-) radical anions are dimerized to form single-bonded (Sc3N@Ih-C80(-))2 dimers.

Journal: :Chemical communications 2003
Feihe Huang Lev N Zakharov Arnold L Rheingold Jason W Jones Harry W Gibson

Water acts as a "molecular clip" to form a supramolecular cryptand structure that improves complexation of a diammonium salt by pseudorotaxane formation, and leads to a novel dimer in the solid state.

Journal: :Chemical communications 2015
Qi Wang Ming Cheng Shuhan Xiong Xiao-Yu Hu Juli Jiang Leyong Wang Yi Pan

Two types of cryptand-based host-guest complexes were constructed successfully, in which P=O functional groups were located at the different positions of the third arms. Consequently, supramolecular poly[2]pseudorotaxanes with almost linear and zigzag shapes were formed in the solid state.

Journal: :Dalton transactions 2011
Kalyan K Sadhu Susan Sen Parimal K Bharadwaj

Two laterally non-symmetric aza-oxa cryptands have been derivatized with the electron-withdrawing fluorophore, 7-nitrobenz-2-oxa-1,3-diazole to obtain the corresponding mono-, bis- and tris-products. In each case, no appreciable emission is observed when the fluorophore is excited due to an efficient photoinduced intramolecular electron transfer (PET) from the lone pair on nitrogen present in t...

Journal: :The Journal of organic chemistry 2010
Grazia Cafeo Howard M Colquhoun Angela Cuzzola Mario Gattuso Franz H Kohnke Luca Valenti Andrew J P White

The novel cryptand in/out-3, containing two tripyrrolemethane units bridged by three 1,3- diisopropylidenbenzene arms, was readily synthesized by a convergent three-step synthesis. It binds fluoride by inclusion with excellent selectivity with respect to a number of other tested anions. The structure of the free receptor and that of its fluoride complex were investigated in solution by NMR spec...

Journal: :Crystal growth & design 2010
Musabbir A Saeed Bryan M Wong Frank R Fronczek Ramaiyer Venkatraman Md Alamgir Hossain

Structural analysis of an adduct of a thiophene-based cryptand with tosylic acid shows the formation of a hybrid amine-water cyclic pentamer composed of four water molecules and one protonated amine in the charged hydrophobic cavity. The bulky tosylate groups remain outside the cavity, making the ligand favorable for hosting water molecules. Ab initio calculations based on density functional th...

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