نتایج جستجو برای: 12 crown 4 ether

تعداد نتایج: 1739084  

Journal: :Dalton transactions 2012
K Duerr O Troeppner J Olah J Li A Zahl T Drewello N Jux J N Harvey I Ivanović-Burmazović

The solution behavior of iron(III) and iron(II) complexes of 5(4),10(4),15(4),20(4)-tetra-tert-butyl-5,10,15,20-tetraphenylporphyrin (H(2)tBuTPP) and the reaction with superoxide (KO(2)) in DMSO have been studied in detail. Applying temperature and pressure dependent NMR studies, the thermodynamics of the low-spin/high-spin equilibrium between bis- and mono-DMSO Fe(II) forms have been quantifie...

2017
VALENTINA N. GLUSHkO

Study of interaction between catechol and tetraethylene glycol dichloride in the n-butanol media, resulting with benzo-15-crown-5 production. Production of nitroand amino-derivatives of benzo-15-crown-5. Determination of their thermogravimetric characteristics. keywords: benzo-15-crown-5, catechol, tetraethylene glycol dichloride, crown ether, gas liquid chromatography, chromate-mass spectrometry

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...

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...

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2011
O A Fedorova Yu V Fedorov I E Labazava E N Gulakova J Saltiel

An E-4-styrylpyridine derivative endowed with 18-crown-6 as a substituent (E-1) was prepared and evaluated in acetonitrile as a potential ditopic ligand for protonated amino acids. The interactions of E-1 with the protonated amino acid perchlorates, ClO(4)(-) H(3)N(+)(CH(2))(n)COOH (n = 2, 5 and 10, A2, A5 and A10, respectively), were studied by optical methods, (1)H NMR and mass spectroscopy. ...

Journal: :Organic & biomolecular chemistry 2011
Yuji Tokunaga Masanori Kawabata Naoki Matsubara

This paper describes the acid/base-mediated three-state translational isomerization of two [2]rotaxanes, each containing N-alkylaniline and N,N-dialkylamine centers as binding sites for threaded dibenzo[24]crown-8 units. Under neutral conditions, the dialkylamine unit predominantly recognized the crown ether component through cooperative binding of a proton; when both amino units were protonate...

Journal: :Dalton transactions 2017
Ana I Ojeda-Amador Antonio J Martínez-Martínez Gemma M Robertson Stuart D Robertson Alan R Kennedy Charles T O'Hara

The structural chemistry of eleven donor complexes of the important Brønsted base potassium 1,1,1,3,3,3-hexamethyldisilazide (KHMDS) has been studied. Depending on the donor, each complex adopted one of five general structural motifs. Specifically, in this study the donors employed were toluene (to give polymeric 1 and dimeric 2), THF (polymeric 3), N,N,N',N'-tetramethylethylenediamine (TMEDA) ...

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...

2013
Volker Müller Gerlinde Frenzen Kurt Dehnicke Dieter Fenske

K 2 Se5 has been prepared by crystallization from a potassium polyselenide solution in DM F. In a similar way [Na(15-crown-5)]2Se5 can be prepared by crystallization from a sodium poly­ selenide solution in D M F in the presence o f 15-crown-5. Both compounds were characterized by FIR spectroscopy as well as by X-ray structure determinations. K 2 Se5: Space group P 2,2,2,, Z 4, 1659 observed in...

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