نتایج جستجو برای: aza crown ether

تعداد نتایج: 44147  

2011
Hongxia Chen Limin Gu Yongmei Yin Kwangnak Koh Jaebeom Lee

Arginine plays an important role in cell division and the functioning of the immune system. We describe a novel method by which arginine can be identified using an artificial monolayer based on surface plasmon resonance (SPR). The affinity of arginine binding its recognition molecular was compared to that of lysine. In fabrication of an arginine sensing interface, a calix[4]crown ether monolaye...

Journal: :Science 1988
C J Pedersen

The discovery of the crown ethers stemmed from efforts to control the catalytic activity of vanadium and copper by complexation with multidentate ligands. The first crown ether, 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclo-octadeca-2,11-diene, was obtained in 0.4% yield during an attempt to prepare a phenolic ligand from catechol and bis(2-chloroethyl)ether. This compound, which complexed with...

2003
Vijaykumar S. Ijeri Ashwini K. Srivastava

Stability constants in 90% (v/v) DMSO /water mixture were evaluated for the complexes of Ag(I), Co(II), Cu(II), Mn(II), Ni(II), Zn(II), Pb(II), Cr(III) and Fe(III) with the macrocyclic compounds, namely, 15-crown-5, benzo-15-crown-5, 18-crown-6, dibenzo18-crown-6, dicyclohexano-18-crown-6, dibenzo-24-crown-8 and dicyclohexano-24-crown-8 by conductometric titrations. A potentiometric study of co...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2008
Kensuke Kurahashi Shigeo Umetani Yoshiki Sohrin

Novel 4-acyl-5-pyrazolones having aza-15-crown-5 (HPMP-A15C5) and aza-18-crown-6 (HPMP-A18C6) moieties as an intramolecular synergist have been synthesized by simple coupling reactions between 1-phenyl-3-methyl-4-chloroacetyl-5-pyrazolone and the corresponding azacrown ethers. The solvent extraction of the divalent metal ions (Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+) and Pb(2+)) were exam...

Journal: :Molecules 2009
Andrey G Vendilo Dmitry I Djigailo Svetlana V Smirnova Irina I Torocheshnikova Konstantin I Popov Vladimir G Krasovsky Igor V Pletnev

The pH-profiles of the extraction of Cs(+) into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been d...

2011
Hui-Ling Hu Geng-Ren Yang Chun-Wei Yeh

In the crystal structure of the title compound, C(17)H(18)N(2)O(4)S(3), mol-ecules are connected into centrosymmetric dimers via weak inter-molecular C-H⋯π inter-actions. These dimers are further connected through a series of weak C-H⋯O hydrogen bonds, while futher C-H⋯π inter-actions involving the phenyl and thia-zoline rings are also observed. The thia-zolidine ring is twisted from the benzen...

2012
Sung Kwon Kang Nam Sook Cho Siyoung Jang

In the title compound, C(12)H(12)N(6)S(4), the two terminal thia-diazole rings are twisted with respect to the central benzene ring, making dihedral angles of 54.28 (4) and 76.56 (3)°. The dihedral angle between the two thia-diazole rings is 27.77 (4)°. Inter-molecular N-H⋯N hydrogen bonds stabilize the crystal packing, linking the mol-ecules into a tape along the b axis.

2008
Li-he Yin Rong Wan Feng Han Bin Wang Jin-tang Wang

In the mol-ecule of the title compound, C(17)H(15)N(3)O(3)S·0.5H(2)O, the thia-diazole ring is oriented with respect to the two 2-methoxy-phenyl rings at dihedral angles of 3.70 (3) and 1.74 (2)°. An intra-molecular N-H⋯O hydrogen bond results in the formation of a planar six-membered ring, which is oriented with respect to the thia-diazole ring at a dihedral angle of 1.33 (3)°. Thus, all of th...

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