نتایج جستجو برای: aza crown ether
تعداد نتایج: 44147 فیلتر نتایج به سال:
The title compound, C33H35N3O5, is the product of the multicomponent condensation of 1-benzyl-4-eth-oxy-carbonyl-piperidin-3-one with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a penta-cyclic system containing the aza-14-crown-4-ether macrocycle, tetra-hydro-pyrimidine, tetra-hydro-pyridine and two benzene rings. The aza-14-crown-4-ether ring adopts a...
The title compound, C24H29NO4, is the product of a Petrenko-Kritchenko condensation of 1,5-bis-(2-formyl-phen-oxy)-3-oxa-pentane, pentan-3-one and methyl-ammonium acetate in ethanol. The mol-ecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intra-molecular C-H⋯O hydrogen bond. The conformation of the C-O-C-C-O-C-C-O-C polyether chain is t-g...
A benign and efficient synthesis of chiral macrocyclic 'aza-crown' ethers of varying ring size is reported. The synthesis involves a Schiff base condensation of ether linked dialdehydes of varying chain length and (1R,2R)-(-)-1,2-diaminocyclohexane under mild conditions to yield the macrocycles, which are subsequently reduced to yield the diamino analogues.
A modified graphene oxide containing aza-9-crown-3 ether units covalently anchored has been prepared; aqueous suspensions of this material in the presence of Li(+), Na(+) and K(+) cations exhibit enhanced electrochemical response, enhanced photoinduced charge separation and longer lifetimes, facts that can be attributed to stabilization of electrons on graphene oxide by the nearby alkali metal ...
Sugar-aza-crown ether-based cavitand 1 can act as a selective turn-on fluorescence sensor for hydrogen sulfate ion in methanol among a series of tested anions. Spectroscopic studies, particularly NMR spectroscopy, revealed that the C-H hydrogen bonding between 1,2,3-triazole ring of cavitand 1 and hydrogen sulfate ion is crucial for the high selectivity of the receptor for hydrogen sulfate.
The title compound, C40H41NO8, is a product of the reduction of the cyclic carbonyl group of the γ-piperidone subunit of the aza-14-crown-4 ether with subsequent re-esterification of its dimethyl butenoate substituent into a monoethyl monomethyl group. The aza-crown macrocycle exhibits a bowl conformation with a dihedral angle of 70.82 (5)° between the benzene rings fused to it. The piperidine ...
A new metal cation probe bearing a central Ir(III) element and 1-aza-15-crown-5-ether substituted pyridyl pyrazolate as the chelate was synthesized. The octahedral molecular structure of was confirmed using single crystal X-ray diffraction analyses. Subsequent photophysical study showed yellow-green emission at approximately 560 nm in both fluid solution and solid state at room temperature. Rem...
Three new electrodes were prepared by incorporating two different charge-transfer complexes and amino crown ether into plasticized PVC membranes. The electrodes showed Nernstian response to triiodide ion over the activity range from 1.0 x 10(-5) to 1.0 x 10(-1) mol x L(-1) with detection limits at approximately 1.0 x 10(-6) mol x L(-1). The resulting electrodes have fast response times (20-30 s...
The title compound, C(29)H(33)NO(8), is a product of the Michael addition of the cyclic secondary amine subunit of the aza-14-crown-4 ether to dimethyl acetyl-enedicarboxyl-ate. The piperidinone ring exhibits a distorted chair conformation, and the dimethyl ethylenedicarboxylate fragment has a cis configuration with a dihedral angle of 78.96 (5)° between the two carboxyl-ate groups. The crystal...
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