نتایج جستجو برای: aza crown ether
تعداد نتایج: 44147 فیلتر نتایج به سال:
Optically active stannolanes and trigonal bipyramidal pentacoordinated tin complexes were readily prepared by radical cyclization of N-propargylated chiral aza-Morita-Baylis-Hillman adducts induced by Bu(3)SnH. A translocated radical through the cyclization attacked the Bu(3)Sn group in an S(H)2 manner.
In the title compound, [Fe(C5H5)(C32H23FN3OS)], both the thia-zolidine ring and the pyrrolidine ring adopt a twist conformation on the N-C(H) bridging bond. Their mean planes are inclined to one another by 10.05 (10)°, and they make dihedral angles of 82.09 (10) and 89.67 (11)°, respectively, with the cyclo-pentane ring. The F atom deviates by -0.0238 (2) Å from the benzene ring to which it is ...
The title compound, C(16)H(12)ClN(3)S, was synthesized by the reaction of 5-(4-methyl-phen-yl)-1,3,4-thia-diazol-2-amine and 4-chloro-benzaldehyde. The thia-diazole ring is essentially planar with mean deviation of 0.0042 Å.
The synthesis of a novel aza-BODIPY dye functionalized with fused pyrazine rings, suitable for use as a selective colorimetric and fluorometric sensor for NH(4)(+), is outlined. In addition to significant fluorescence quenching, an obvious colorimetric change from green to red-pink is observed enabling facile "naked-eye" detection of NH(4)(+).
Sixteen lipophilic N-(X)sulfonyl carbamoyl lariat ethers with polyether ring sizes of 12-crown-4, 14-crown-4, 15-crown-5, and 18-crown-6 are utilized for competitive alkali metal cation extractions from aqueous solutions into chloroform. Variation of the electron-withdrawing properties of X in the series of methyl, phenyl, 4-nitrophenyl, and trifluoromethyl allows the influence of the acidity o...
A series of crown ethers, 12-crown-4, 15-crown-5, 18-crown-6, and dibenzo-30-crown-10, are examined as a possible means of shifting the mobilities of peptide ions. In this approach, a crown ether is added to a solution containing a mixture of peptides and is electrosprayed into the gas phase in order to create distributions of peptide-crown complexes. The ion complexes have different mobilities...
Responsive supramolecular gels were constructed from crown ether terminated four-arm star poly(epsilon-caprolactone) (PCL-DB24C8) and dibenzylammonium-terminated two-arm PCL-DBAS (see scheme), exploiting the formation of pseudorotaxane linkages between crown ether and ammonium moieties. The resultant supramolecular gels exhibit thermo- and pH-induced reversible gel-sol transition.
The creation of novel crown ether-paraquat polypseudorotaxane networks, constructed by bisparaquat monomers threading into the cavity of the crown ether units of linear supramolecular polymers that are formed based on the quadruple hydrogen bonded unit ureidopyrimidinone (Upy) in the concentrated solution, is described.
The title compound, C(16)H(14)ClNOS, a potent anti-bacterial chemical, features a dihedral angle of 49.4 (1)° between the 4-tolyl and thia-zolidinone rings, and a dihedral angle of 87.2 (5)° between the thia-zolidinone and 4-chloro-phenyl rings.
A selective and sensitive turn-on fluorescent NIR probe for cysteine has been developed. Cleavage of 2,4-dinitrobenzenesulfonyl (DNBS) with thiols switches the weakly fluorescent aza-BODIPY dye (λ(em) = 734 nm, Φ(f) = 0.03) to a strongly fluorescent species in the NIR region (λ(em) = 755 nm, Φ(f) = 0.14).
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