نتایج جستجو برای: crown ether addition

تعداد نتایج: 750363  

Journal: :Dalton transactions 2016
Teng-Hao Chen Andreas Schneemann Roland A Fischer Seth M Cohen

A series of unprecedented crown ether- and thiacrown ether-derivatized benzene dicarboxylic acid (H2bdc) ligands has been synthesized and incorporated into the prototypical isoreticular metal-organic framework (IRMOF) and UiO-66 materials. In the case of UiO-66, only MOFs comprised from a mixed-ligand composition, requiring both unsubstituted bdc and crown ether containing ligands, could be pre...

2012
Yu-Feng Wang

In the title compound, C(7)H(10)N(+)·ClO(4) (-)·C(12)H(24)O(6), the 4-methyl-anilinium cation inter-acts with an 18-crown-6 mol-ecule forming a rotator-stator-like structure through bifurcated N-H⋯(O,O) hydrogen bonds between the ammonium group of the cation and the O atoms of the crown ether mol-ecule. All three components of the structure possess mirror symmetry. The benzene ring is inclined ...

2001
Joseph T. Hupp Yuhua Dong

Recently we reported the profound effects of second-sphere crown ether binding upon the redox energetics and intervalence spectroscopy of selected mixed-valence (Crowd metal complex associatino is driven primarily by ether oxygen/ ammine hydrogen interactions, where the H-bond-donating capability of NH3 is greatly enhanced by coordination to a transition-metal cation.) For delocalized species s...

2010
Hien Ngoc Phan Hans-Wolfram Lerner Michael Bolte

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...

2017
Bing-Bing Wu Zhong-Xia Wang

A series of crown ether complexes of potassium quinolin-8-olates were synthesized and characterized. Catalysis of these complexes towards the ring-opening polymerization of rac-lactide was evaluated. The crown ether complexes of potassium quinolin-8-olate and potassium 2-methylquinolin-8-olate exhibited high catalytic activity and good molecular weight control. The 18-crown-6 complex of potassi...

2012
Le Tuan Anh Truong Hong Hieu Anatoly T. Soldatenkov Nadezhda M. Kolyadina Victor N. Khrustalev

The title compound, C(25)H(28)N(2)O(5), is a product of the Petrenko-Kritchenko condensation of N-acetyl-piperidone with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a fused penta-cyclic system containing an aza-14-crown-3-ether macrocycle, two piperidone and two benzene rings. The aza-14-crown-3-ether ring adopts a bowl conformation. The dihedral angle...

2010
Jia-Zhen Ge Min-Min Zhao Ping-Ping Shi

The reaction of dimethyl-amine, 18-crown-6, and perchloric acid in methanol yields the title compound, C(2)H(8)N(+)·ClO(4) (-)·C(12)H(24)O(6)·H(2)O. The dimethyl-ammonium cation and the water mol-ecule inter-act with the 18-crown-6 unit: N-H⋯O hydrogen bonds are formed between the ammonium NH(2) (+) group and four O atoms of the crown ether, while the water mol-ecule on the other side of 18-cro...

Journal: :Inorganic chemistry 2005
Atsuko Suzumura Dharam Paul Hideki Sugimoto Satoshi Shinoda Ryan R Julian J L Beauchamp Junji Teraoka Hiroshi Tsukube

A series of supramolecular complexes of various cytochrome c proteins with 18-crown-6 derivatives behave as cold-active synzymes in the H2O2 oxidation of racemic sulfoxides. This interesting behavior contrasts with native functionality, where the employed proteins act as electron transfer carriers. ESI-MS. UV, CD, and Raman spectroscopic characterizations reveal that four or five 18-crown-6 mol...

Journal: :Dalton transactions 2007
Zakaria Halime Mohammed Lachkar Loïc Toupet Athanassios G Coutsolelos Bernard Boitrel

Simple chelating agents have been synthesized using a porphyrin and a covalently linked crown-ether. Depending on the relative spatial arrangement of both motifs, the resulting ligands, either a macrotricycle or bis-macrocycles, differ one from another by their flexibility or their aptitude to chelate bivalent or trivalent cations. The coordination chemistry as well as the structural study of t...

Journal: :Chemistry 2001
A J Wright S E Matthews W B Fischer P D Beer

A series of novel resorcin-[4]arenes with extended pi systems have been synthesised and developed as potassium-selective transporters. Resorcin[4]arenes that feature crown ether moieties function as efficient carriers of K+ across bulk liquid membranes showing enhanced selectivity over the other alkali metal ions relative to a model system (benzo[15]crown-5). Incorporation of functionalities su...

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